http://www.mdpi.com/journal/molecules Latest open access articles published in Molecules at http://www.mdpi.com/journal/molecules http://www.mdpi.com/1420-3049/18/6/7120 A series of new peptide dendrimers with amphiphilic surface, designed around a dendronized ornithine (Orn) core were synthesized and characterized by ESI-MS, 1H-, 13C- NMR, and CD spectrometry. An improved antimicrobial potency against S. aureus and E. coli was detected as a result of an increased charge, higher branching and variable lipophilicity of the residues located at the C-terminus. Minimal inhibitory concentration (MIC) values indicated that the selected dendrimers were not sensitive to the physiological concentration of Na+ and K+ ions (100 mM), but expressed reduced potency at 10 mM concentration of Mg2+ and Ca2+ ions. Circular dichroism (CD) curves measured under various conditions revealed structure and solvent-dependent curve evolution. ESI-MS studies of gas-phase interactions between selected dendrimers and both anionic (DMPG) and neutral (DMPC) phospholipids revealed the presence of variously charged dendrimer/phospholipid aggregates with 1:1 to 1:5 stoichiometry. The collision-induced fragmentation (CID) of the most abundant [dendrimer/phospholipid]2+ ions of the 1:1 stoichiometry demonstrated that the studied dendrimers formed stronger complexes with anionic DMPG. Both phospholipids have higher affinity towards dendrimers with a more compact structure. Higher differences in CID energy necessary for dissociation of 50% of the complex formed by dendrimers with DMPG vs. DMPC (DCID50) correlate with a lower hemotoxicity. Mass spectrometry results suggest that for a particular group of compounds the DCID50 might be one of the important factors explaining selectivity of antimicrobial peptides and their branched analogs targeting the bacterial membrane. Both circular dichroism and mass spectrometry studies demonstrated that dendrimers of Nα- and Nε-series possess a different conformation in solution and different affinity to model phospholipids, what might influence their specific microbicidal mechanism. Molecules 2013-06-18 18 6 Article 10.3390/molecules18067120 7120 7144 1420-3049 2013-06-18 doi: 10.3390/molecules18067120 Piotr Polcyn Paulina Zielinska Magdalena Zimnicka Anna Troć Przemysław Kalicki Jolanta Solecka Anna Laskowska Zofia Urbanczyk-Lipkowska http://www.mdpi.com/1420-3049/18/6/7103 NMR is commonly used to investigate macromolecular interactions. However, sensitivity problems hamper its use for studying such interactions at low physiologically relevant concentrations. At high concentrations, proteins or peptides tend to aggregate. In order to overcome this problem, we make use of reductive 13C-methylation to study protein interactions at low micromolar concentrations. Methyl groups in dimethyl lysines are degenerate with one 13CH3 signal arising from two carbons and six protons, as compared to one carbon and three protons in aliphatic amino acids. The improved sensitivity allows us to study protein-protein or protein-peptide interactions at very low micromolar concentrations. We demonstrate the utility of this method by studying the interaction between the post-translationally lipidated hypervariable region of a human proto-oncogenic GTPase K-Ras and a calcium sensor protein calmodulin. Calmodulin specifically binds K-Ras and modulates its downstream signaling. This binding specificity is attributed to the unique lipidated hypervariable region of K-Ras. At low micromolar concentrations, the post-translationally modified hypervariable region of K-Ras aggregates and binds calmodulin in a non-specific manner, hence conventional NMR techniques cannot be used for studying this interaction, however, upon reductively methylating the lysines of calmodulin, we detected signals of the lipidated hypervariable region of K-Ras at physiologically relevant nanomolar concentrations. Thus, we utilize 13C-reductive methylation of lysines to enhance the sensitivity of conventional NMR methods for studying protein interactions at low concentrations. Molecules 2013-06-18 18 6 Article 10.3390/molecules18067103 7103 7119 1420-3049 2013-06-18 doi: 10.3390/molecules18067103 Tanmay Chavan Sherwin Abraham Vadim Gaponenko http://www.mdpi.com/1420-3049/18/6/7093 Two new resveratrol trimer derivatives, named rheumlhasol A (1) and rheumlhasol B (2) were isolated from the methanolic extract of roots of Rheum lhasaense A. J. Li et P. K. Hsiao together with four known resveratrol dimer derivatives, including maximol A (3), gnetin C (4), e-viniferin (5), and pallidol (6). The structures were determined by combined spectroscopic methods and by comparison of their spectral data with those reported in the literature. All the compounds isolated from R. lhasaense were tested for their ability to scavenge1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Molecules 2013-06-18 18 6 Article 10.3390/molecules18067093 7093 7102 1420-3049 2013-06-18 doi: 10.3390/molecules18067093 Wen-Bo Liu Lin Hu Qun Hu Na-Na Chen Qing-Song Yang Fang-Fang Wang http://www.mdpi.com/1420-3049/18/6/7081 A series of monoazo disperse dyes derived from arylazothienopyridazines were synthesized. Fastness properties of dyed polyester samples were measured. Most of the dyed fabrics tested displayed excellent washing and perspiration fastness and moderate light fastness. Finally, the biological activity of the synthesized dyes against Gram positive bacteria, Gram negative bacteria and yeast were evaluated. Molecules 2013-06-18 18 6 Article 10.3390/molecules18067081 7081 7092 1420-3049 2013-06-18 doi: 10.3390/molecules18067081 Saleh Al-Mousawi Morsy El-Apasery Huda Mahmoud http://www.mdpi.com/1420-3049/18/6/7071 We have synthesized a novel amphiphilic naphthalene imide bearing a cationic dendrimer wedge (NID). NID molecules in water self-assemble to form a two-dimensional ribbon, which further coils to give a linear supramolecular nanofiber. The sample solution showed linear dichroism (LD) upon stirring of the solution, where NID nanofibers dominantly align at the center of vortex by hydrodynamic interaction with the downward torsional flows. Molecules 2013-06-17 18 6 Article 10.3390/molecules18067071 7071 7080 1420-3049 2013-06-17 doi: 10.3390/molecules18067071 Taiki Yamamoto Akihiko Tsuda http://www.mdpi.com/1420-3049/18/6/7058 Antimicrobial peptides (AMPs) from the dermaseptin and phylloseptin families were isolated from the skin secretion of Phyllomedusa nordestina, a recently described amphibian species from Northeastern Brazil. One dermaseptin and three phylloseptins were chosen for solid phase peptide synthesis. The antiprotozoal and antimicrobial activities of the synthetic peptides were determined, as well as their cytotoxicity in mouse peritoneal cells. AMPs are being considered as frameworks for the development of novel drugs inspired by their mechanism of action. Molecules 2013-06-17 18 6 Article 10.3390/molecules18067058 7058 7070 1420-3049 2013-06-17 doi: 10.3390/molecules18067058 Guilherme Brand Raimunda Santos Luisa Arake Valdelânia Silva Leiz Veras Vladimir Costa Carlos Costa Selma Kuckelhaus José Alexandre Maria Feio José Leite http://www.mdpi.com/1420-3049/18/6/7035 Solvent chirality transfer of (S)-/(R)-limonenes allows the instant generation of optically active PF8P2 aggregates with distinct circular dichroism (CD)/circularly polarized luminescence (CPL) amplitudes with a high quantum yield of 16–20%. The present paper also reports subtle mirror-symmetry-breaking effects in CD-/CPL-amplitude and sign, CD/UV-vis spectral wavelengths, and photodynamics of the aggregates, though the reasons for the anomaly are unsolved. However, these photophysical properties depend on (i) the chemical natures of chiral and achiral molecules when used in solvent quantity, (ii) clockwise and counterclockwise stirring operations, and (iii) the order of addition of limonene and methanol to the chloroform solution. Molecules 2013-06-17 18 6 Article 10.3390/molecules18067035 7035 7057 1420-3049 2013-06-17 doi: 10.3390/molecules18067035 Michiya Fujiki Yoshifumi Kawagoe Yoko Nakano Ayako Nakao http://www.mdpi.com/1420-3049/18/6/7023 Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancer cells. EGFR-mediated signaling involves inflammatory gene expression including cyclooxygenase (COX)-2 and interleukin (IL)-8, and is associated with cancer pathogenesis. In a search of phytochemicals with anti-inflammatory activity, the COX-2 and IL-8 inhibitory activities of some marine compounds were examined. After screening these compounds 11-episinulariolide acetate (1) from soft coral exhibited the most potent activity. Reverse-transcription PCR; western blotting; ELISA and luciferase assays were used to test the effect of compound 1 on EGF-stimulated expressions of COX-2 and IL-8 in A431 human epidermoid carcinoma cells. After exposure to 10 μM of compound 1, expression levels of COX-2 and IL-8 were reduced. In addition; intracellular Ca2+ increase and Ca2+-dependent transcription factor activation were blocked by compound 1. Thus, compound 1 can potentially serve as a lead compound for targeting Ca2+ signaling-dependent inflammatory diseases. Molecules 2013-06-17 18 6 Article 10.3390/molecules18067023 7023 7034 1420-3049 2013-06-17 doi: 10.3390/molecules18067023 Wen-Li Hsu Siou-Jin Chiu Yao-Ting Tsai Che-Mai Chang Jaw-Yan Wang Eric Wang Ming-Feng Hou Chiung-Yao Huang Jyh-Horng Sheu Wei-Chiao Chang http://www.mdpi.com/1420-3049/18/6/7004 Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants. Molecules 2013-06-14 18 6 Article 10.3390/molecules18067004 7004 7022 1420-3049 2013-06-14 doi: 10.3390/molecules18067004 Yin Thoo Swee Ho Faridah Abas Oi Lai Chun Ho Chin Tan http://www.mdpi.com/1420-3049/18/6/6990 The platinum(II) complexes trans-[PtCl2(Ln)2]∙xSolv 1–13 (Solv = H2O or CH3OH), involving N6-benzyladenosine-based N-donor ligands, were synthesized; Ln stands for N6-(2-methoxybenzyl)adenosine (L1, involved in complex 1), N6-(4-methoxy-benzyl)adenosine (L2, 2), N6-(2-chlorobenzyl)adenosine (L3, 3), N6-(4-chlorobenzyl)-adenosine (L4, 4), N6-(2-hydroxybenzyl)adenosine (L5, 5), N6-(3-hydroxybenzyl)-adenosine (L6, 6), N6-(2-hydroxy-3-methoxybenzyl)adenosine (L7, 7), N6-(4-fluoro-benzyl)adenosine (L8, 8), N6-(4-methylbenzyl)adenosine (L9, 9), 2-chloro-N6-(3-hydroxy-benzyl)adenosine (L10, 10), 2-chloro-N6-(4-hydroxybenzyl)adenosine (L11, 11), 2-chloro-N6-(2-hydroxy-3-methoxybenzyl)adenosine (L12, 12) and 2-chloro-N6-(2-hydroxy-5-methylbenzyl)adenosine (L13, 13). The compounds were characterized by elemental analysis, mass spectrometry, IR and multinuclear (1H-, 13C-, 195Pt- and 15N-) and two-dimensional NMR spectroscopy, which proved the N7-coordination mode of the appropriate N6-benzyladenosine derivative and trans-geometry of the title complexes. The complexes 1–13 were found to be non-toxic in vitro against two selected human cancer cell lines (HOS and MCF7; with IC50 > 50.0 µM). However, they were found (by ESI-MS study) to be able to interact with the physiological levels of the sulfur-containing biogenic biomolecule L-methionine by a relatively simple 1:1 exchange mechanism (one Ln molecule was replaced by one L-methionine molecule), thus forming a mixed-nitrogen/sulfur-ligand dichlorido-platinum(II) coordination species. Molecules 2013-06-14 18 6 Article 10.3390/molecules18066990 6990 7003 1420-3049 2013-06-14 doi: 10.3390/molecules18066990 Pavel Štarha Igor Popa Zdeněk Trávníček Ján Vančo http://www.mdpi.com/1420-3049/18/6/6969 12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione (quinone 2) served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating) or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the experimental conditions used. Molecules 2013-06-14 18 6 Review 10.3390/molecules18066969 6969 6989 1420-3049 2013-06-14 doi: 10.3390/molecules18066969 George Majetich Yong Zhang Xinrong Tian Ge Zou Yang Li Yangyang Wang Shougang Hu Eric Huddleston http://www.mdpi.com/1420-3049/18/6/6952 Allosamidins, which are secondary metabolites of the Streptomyces species, have chitin-mimic pseudotrisaccharide structures. They bind to catalytic centers of all family 18 chitinases and inhibit their enzymatic activity. Allosamidins have been used as chitinase inhibitors to investigate the physiological roles of chitinases in a variety of organisms. Two prominent biological activities of allosamidins were discovered, where one has anti-asthmatic activity in mammals, while the other has the chitinase-production- promoting activity in allosamidin-producing Streptomyces. In this article, recent studies on the novel biological activities of allosamidins are reviewed. Molecules 2013-06-13 18 6 Review 10.3390/molecules18066952 6952 6968 1420-3049 2013-06-13 doi: 10.3390/molecules18066952 Shohei Sakuda Hiromasa Inoue Hiromichi Nagasawa http://www.mdpi.com/1420-3049/18/6/6936 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field. Molecules 2013-06-13 18 6 Review 10.3390/molecules18066936 6936 6951 1420-3049 2013-06-13 doi: 10.3390/molecules18066936 Wilfried Schwab http://www.mdpi.com/1420-3049/18/6/6919 A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and few studies on the applicability of reference extractives for quantitative analysis have been presented. Using Salvia miltiorrhiza Bunge as an example in this paper, we first present a preliminary discussion on the feasibility and applicability of reference extractives for the quantitative analysis of TCMs. The reference extractive of S. miltiorrhiza Bunge, comprised of three pharmacological marker compounds, namely cryptotanshinone, tanshinone I and tanshinone IIA, was prepared from purchased Salvia miltiorrhiza Bunge by extraction with acetone under reflux, followed by silica gel column chromatography with stepwise elution with petroleum ether-ethyl acetate (25:1, v/v, 4.5 BV) to remove the non-target components and chloroform-methanol (10:1, v/v; 3 BV) to yield a crude reference extractive solution. After concentration, the solution was further purified by preparative reversed-phase HPLC on a C18 column with isocratic elution with 77% methanol aqueous solution to yield the total reference extractive of S. miltiorrhiza Bunge. Thereafter, the reference extractive was applied to the quality assessment of S. miltiorrhiza Bunge using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The validation of the method, including linearity, sensitivity, repeatability, stability and recovery testing, indicated that this method was valid, reliable and sensitive, with good reproducibility. The developed method was successfully applied to quantify seven batches of samples collected from different regions in China and the results were also similar to those obtained using reference standards, with relative standard deviation (RSD) <3%. Preparation of a reference extractive of S. miltiorrhiza Bunge was significantly less expensive and time consuming than preparation of a corresponding reference standard. Quantitative analysis using a reference extractive was shown to be simple, low-cost, time-saving and practical, with high sensitivity and good stability; and is, therefore, a strong alternative to the use of reference standards. Molecules 2013-06-13 18 6 Article 10.3390/molecules18066919 6919 6935 1420-3049 2013-06-13 doi: 10.3390/molecules18066919 Wen-Guang Jing Jun Zhang Li-Yan Zhang Dong-Zhe Wang Yue-Sheng Wang An Liu http://www.mdpi.com/1420-3049/18/6/6908 A novel annexin A5 derivative (cys-annexin A5) with a single cysteine residue at its C-terminal has been developed and successfully labeled in high labeling yield with 99mTc by a ligand exchange reaction. Like the 1st generation 99mTc-HYNIC-annexin A5, the novel 99mTc-cys-annexin A5 derivative shows in normal mice mainly renal and, to a lesser extent, hepatobiliary excretion. In rat models of hepatic apoptosis there was 283% increase in hepatic uptake of 99mTc-cys-annexin A5 as compared to normal mice. The results indicate that the novel 99mTc-cys-annexin A5 is a potential apoptosis imaging agent. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066908 6908 6918 1420-3049 2013-06-10 doi: 10.3390/molecules18066908 Chunxiong Lu Quanfu Jiang Minjin Hu Cheng Tan Yu Ji Huixin Yu Zichun Hua http://www.mdpi.com/1420-3049/18/6/6898 A new dihydrochalcone derivative, 4',6'-dihydroxy-2',4-dimethoxy-5'-(2''-hydroxybenzyl)dihydrochalcone (1) and one known dihydrochalcone, 4',6'-dihydroxy-2',4- dimethoxydihydrochalcone (2) were isolated from leaves and twigs of Cyathostemma argenteum. Their structures were established by spectral methods, mainly 2D NMR spectroscopic techniques, which involved combined applications of DEPT, COSY, HMQC and HMBC. The molecular structure of 1 was also confirmed by single crystal X-ray diffraction. The test compounds 1 and 2 displayed significant inhibitory activity at a dose of 1 mg/ear on edema formation at all determination times, with similar intensity as phenylbutazone. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066898 6898 6907 1420-3049 2013-06-10 doi: 10.3390/molecules18066898 Jariya Somsrisa Puttinan Meepowpan Samroeng Krachodnok Haruthai Thaisuchat Sittiporn Punyanitya Narong Nantasaen Wilart Pompimon http://www.mdpi.com/1420-3049/18/6/6883 The apical sodium-dependent bile salt transporter (ASBT) plays a pivotal role in maintaining bile acid homeostasis. Inhibition of ASBT would reduce bile acid pool size and lower cholesterol levels. In this report, a series of novel arylsulfonylaminobenzanilides were designed and synthesized as potential inhibitors of ASBT. Most of them demonstrated great potency against ASBT’s bile acid transport activity. In particular, compound 5g2 inhibited ASBT activity with an IC50 value of 0.11 μM. These compounds represent potential cholesterol-lowering drugs. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066883 6883 6897 1420-3049 2013-06-10 doi: 10.3390/molecules18066883 Hong-Tao Liu Hong-Wei He Xiao-Guang Bai Ju-Xian Wang Chang-Liang Xu Shi-Ying Cai Rong-Guang Shao Yu-Cheng Wang http://www.mdpi.com/1420-3049/18/6/6866 Artemisinin (ART) and its derivatives artesunate (AS), dihydroartemisinin (DHA) are a group of drugs containing a sesquiterpene lactone used to treat malaria. Previously, AS was shown to not have antibacterial activity but to significantly increase the antibacterial activities of β-lactam antibiotics against E. coli. Herein, molecular docking experiments showed that ART, AS and DHA could dock into AcrB very well, especially DHA and AS; both DHA and AS had the same docking pose. The affinity between AS and AcrB seemed weaker than that of DHA, while the succinate tail of AS, which was like a “bug”, could extend in the binding pocket very well. Imitating the parent nucleus of DHA and the succinate tail of AS, twenty-one DHA derivatives 4a–u were designed and synthesized. Among them, seventeen were new compounds. The synergistic effects against E. coli AG100A/pET28a-AcrB showed among the new structures 4k, 4l, 4m, 4n, and 4r exhibited significant synergism with β-lactam antibiotics although they had no direct antibacterial activities themelves. The bacterial growth assay showed that only 4k in combination with ampicillin or cefuroxime could totally inhibit bacterial growth from 0 to 12 h, demonstrating that 4k had the best antibacterial enhancement effect. In conclusion, our results provided a new idea and several candidate compounds for antibacterial activity enhancers against multidrug resistant E. coli. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066866 6866 6882 1420-3049 2013-06-10 doi: 10.3390/molecules18066866 Chong Wu Jian Liu Xichun Pan Wenying Xian Bin Li Wei Peng Jingfang Wang Dacheng Yang Hong Zhou http://www.mdpi.com/1420-3049/18/6/6852 Limonium brasiliense is a common plant on the southern coast of Brazil. The roots are traditionally used for treatment of premenstrual syndrome, menstrual disturbances and genito-urinary infections. Pharmaceutical preparations obtained from its roots and used for these purposes were marketed in Brazil in the 1980s and 1990s. Currently, the Brazilian Drug Agency (National Health Surveillance Agency, ANVISA) has canceled the registration of these products, and their use was discontinued because of a lack of studies to characterize the plant raw material and ensure the effectiveness and safety of its use. The aim of the present study was to develop and validate an analytical method to determine the content of total polyphenols (TP) in an extract from L. brasiliense roots, by the UV/Vis spectrophotometric method. L. brasiliense roots were extracted in acetone:water (7:3, v/v-10% w/v). The crude extract was used to develop a method for TP assay. The method was validated according to national and international guidelines. The optimum conditions for analysis time, wavelength, and standard substance were 30 min, 760 nm, and pyrogallol, respectively. Under these conditions, validation by UV/Vis spectrophotometry proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform. This methodology complies with the requirements for analytical application and to ensure the reliability of the results. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066852 6852 6865 1420-3049 2013-06-10 doi: 10.3390/molecules18066852 Andressa Blainski Gisely Lopes João de Mello http://www.mdpi.com/1420-3049/18/6/6829 The formation of halogen bonded complexes formed between the trifluorohalomethanes CF3Cl, CF3Br and CF3I and the Lewis bases benzene and toluene at temperatures below 150K was investigated using FTIR and Raman spectroscopy. Experiments using liquid krypton as solvent show that for both CF3Br and CF3I substantial fractions of the monomers can be involved in 1:1 complexes. In addition, weak absorptions illustrating the formation of 2:1 complexes between CF3I and benzene are observed. Using spectra recorded at temperatures between 120 and 140 K, observed information on the relative stability was obtained for all complexes by determining the complexation enthalpies in solution. The resulting values for CF3Br.benzene, CF3I.benzene and (CF3I)2.benzene are −6.5(3), −7.6(2) and −14.5(9) kJ mol−1. The values for CF3Br.toluene and CF3I.toluene are −6.2(5) and −7.4(5) kJ mol−1. The experimental complexation enthalpies are compared with theoretical data obtained by combining results from MP2/aug-cc-pVDZ(-PP) and MP2/aug-cc-pVTZ(-PP) ab initio calculations, from statistical thermodynamical calculations and from Monte Carlo Free Energy Perturbation simulations. The data are also compared with results derived for other C-X···π halogen bonded complexes involving unsaturated Lewis bases such as ethene and ethyne. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066829 6829 6851 1420-3049 2013-06-10 doi: 10.3390/molecules18066829 Nick Nagels Dieter Hauchecorne Wouter Herrebout http://www.mdpi.com/1420-3049/18/6/6804 This review is oriented toward the asymmetric transfer hydrogenation (ATH) of imines regarding mostly fundamental, yet important topics from the practical point of view. Development of analytical methods for the monitoring of ATH (i.e., kinetics and stereoselectivity) belongs to those topics, as well as studies on the influence of reaction conditions and structural variations on the reaction performance. The second part is devoted to the reaction mechanism with the emphasis on imine ATH and catalyst behaviour under acidic conditions. The review also addresses the asymmetric hydrogenation (AH) of ketones and imines using molecular hydrogen and the application of ATH in pharmaceutical projects. The contributions of our group to each area are included. Molecules 2013-06-10 18 6 Review 10.3390/molecules18066804 6804 6828 1420-3049 2013-06-10 doi: 10.3390/molecules18066804 Jiří Václavík Petr Šot Beáta Vilhanová Jan Pecháček Marek Kuzma Petr Kačer http://www.mdpi.com/1420-3049/18/6/6792 Palm sugar-like flavouring (PSLF) is a type of flavour product that is formed by heating amino acids and sugar under specific heating conditions. Unfortunately, PSLF has a salty taste and contains high amounts of acrylamide. Hence, the objective of this research was to reduce saltiness and acrylamide without negatively affecting the aroma properties of PSLF. A decrease in the sodium phosphate (NaHPO4) buffer concentration from 0.20 to 0.02 M was found to reduce sodium to approximately 15% of the level found in original PSLF. A further decrease (~25%) in the sodium content was achieved by removing monobasic sodium phosphate (NaH2PO4) from the buffer system. Meanwhile, the addition of CaCl2 at 20–40 mg/L reduced the acrylamide content in PSLF by as much as 58%. A CaCl2 concentration of 20 mg/mL was most favourable as it most efficiently suppressed acrylamide formation while providing an acceptably high flavour yield in PSLF. In view of the high acrylamide content in PSLF, additional work is necessary to further reduce the amount of acrylamide by controlling the asparagine concentration in the precursor mixture. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066792 6792 6803 1420-3049 2013-06-10 doi: 10.3390/molecules18066792 Phui Tan Chin Tan Faridah Abas Chun Ho Wan Mustapha http://www.mdpi.com/1420-3049/18/6/6782 Water is a small molecule that nevertheless perturbs, sometimes significantly, the electronic properties of an enzyme’s active site. In this study, interactions of a water molecule with the ferric heme and the compound I (Cpd I) intermediate of cytochrome P450 are studied. Energy decomposition analysis (EDA) schemes are used to investigate the physical origins of these interactions. Localized molecular orbital EDA (LMOEDA) implemented in the quantum chemistry software GAMESS and the EDA method implemented in the ADF quantum chemistry program are used. EDA reveals that the electrostatic and polarization effects act as the major driving force in both of these interactions. The hydrogen bonding in the Cpd I•••H2O complex is similar to that in the water dimer; however, the relative importance of the electrostatic effect is somewhat larger in the water dimer. Molecules 2013-06-10 18 6 Article 10.3390/molecules18066782 6782 6791 1420-3049 2013-06-10 doi: 10.3390/molecules18066782 Nandun Thellamurege Hajime Hirao http://www.mdpi.com/1420-3049/18/6/6748 This review provides an update on our understanding of the chemical reactions (lipid oxidation, Strecker and Maillard reactions, thiamine degradation) and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused on ruminant species. This knowledge is essential in order to understand, control, and improve the quality of food products. More studies are necessary to fully understand the role of each compound in the overall cooked meat flavour and their possible effect in consumer acceptability. Molecules 2013-06-07 18 6 Review 10.3390/molecules18066748 6748 6781 1420-3049 2013-06-07 doi: 10.3390/molecules18066748 Virginia Resconi Ana Escudero María Campo http://www.mdpi.com/1420-3049/18/6/6734 Effective oral delivery of protein and peptide drugs remains an active topic in scientific research. In this study, matrix type microspheres were prepared with Eudragit® L100 containing N-trimethylchitosan chloride to improve the permeation of insulin across the intestinal epithelium via the paracellular pathway. Insulin loaded microspheres were initially formulated in accordance with a factorial design (23) and manufactured by means of a single water-in-oil emulsification/evaporation method. Based on external and internal morphology two microsphere formulations were selected from the initial formulations for further investigation in terms of particle size, dissolution behaviour and in vitro insulin transport across excised rat intestinal tissue. The initial eight microsphere formulations exhibited drug loading capacities ranging from 27.9–52.4% with different shapes and internal structures. The two selected microsphere formulations had average particle sizes of 157.3 ± 31.74 µm and 135.7 ± 41.05 µm, respectively, and mean dissolution time values for insulin release of 34.47 and 42.63 min, respectively. In vitro transport of insulin across excised rat intestinal tissue from the two selected microsphere formulations was 10.67–fold and 9.68–fold higher than the control group (insulin alone). The microsphere delivery system prepared from Eudragit® L100 containing N-trimethylchitosan chloride is therefore a promising candidate for effective oral insulin delivery. Molecules 2013-06-07 18 6 Article 10.3390/molecules18066734 6734 6747 1420-3049 2013-06-07 doi: 10.3390/molecules18066734 Etienne Marais Josias Hamman Lissinda Plessis Righard Lemmer Jan Steenekamp http://www.mdpi.com/1420-3049/18/6/6723 Protected L-homoDMDP en-8 and its C-6 epimer en-7 were prepared through two different pathways starting from the vinylpyrrolidine en-9. Based on the NMR and X-ray analysis, the stereochemistry of homoDMDP at C-6 was confirmed to be consistent with reported data. Compounds en-7 and en-8 are general intermediates for the synthesis of a series of 6-C-alkylated DMDP-related natural products, such as broussonetine G, homoDMDP-7-O-apioside, homoDMDP-7-O-b-D-xyloside and so on. Molecules 2013-06-07 18 6 Article 10.3390/molecules18066723 6723 6733 1420-3049 2013-06-07 doi: 10.3390/molecules18066723 Mu-Hua Huang Yi-Xian Li Yue-Mei Jia Chu-Yi Yu http://www.mdpi.com/1420-3049/18/6/6679 In order to present the relationship between ESR spectroscopy and isotope effects three levels are considered: (i) ESR spectroscopy is described on a general level up to the models for interpretation of the experimental spectra, which go beyond the usually used time and mass independent spin-Hamilton operator, (ii) the main characteristics of the generalized isotope effects are worked out, and finally (iii) the basic, mainly quantum mechanical effects are used to describe the coupling of electron spins with the degrees of freedom, which are accessible under the selected conditions, of the respective paramagnetic object under investigation. The ESR parameters and the respective models are formalized so far, that they include the time and mass depending influences and reflect the specific isotope effects. Relations will be established between the effects in ESR spectra to spin relaxation, to spin exchange, to the magnetic isotope effect, to the Jahn-Teller effects, as well as to the influence of zero-point vibrations. Examples will be presented which demonstrate the influence of isotopes as well as the kind of accessible information. It will be differentiated with respect to isotope effects in paramagnetic centres itself and in the respective matrices up to the technique of ESR imaging. It is shown that the use of isotope effects is indispensable in ESR spectroscopy. Molecules 2013-06-07 18 6 Review 10.3390/molecules18066679 6679 6722 1420-3049 2013-06-07 doi: 10.3390/molecules18066679 Reinhard Stößer Werner Herrmann http://www.mdpi.com/1420-3049/18/6/6663 In this study, the acetylcholinesterase inhibition and in vitro and in vivo antioxidant activities of Ganoderma lucidum grown on germinated brown rice (GLBR) were evaluated. In antioxidant assays in vitro, GLBR was found to have strong metal chelating activity, DPPH, ABTS, hydroxyl and superoxide radical scavenging activity. Cell-based antioxidant methods were used, including lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. In antioxidant assays in vivo, mice were administered with GLBR and this significantly enhanced the activities of antioxidant enzymes in the mice sera, livers and brains. The amount of total phenolic and flavonoid compounds were 43.14 mg GAE/g and 13.36 mg CE/g dry mass, respectively. GLBR also exhibited acetylcholinesterase inhibitory activity. In addition, HPLC analyses of GLBR extract revealed the presence of different phenolic compounds. These findings demonstrate the remarkable potential of GLBR extract as valuable source of antioxidants which exhibit interesting acetylcholinesterase inhibitory activity. Molecules 2013-06-07 18 6 Article 10.3390/molecules18066663 6663 6678 1420-3049 2013-06-07 doi: 10.3390/molecules18066663 Md. Hasnat Mehnaz Pervin Beong Lim http://www.mdpi.com/1420-3049/18/6/6620 The indole nucleus is an important element of many natural and synthetic molecules with significant biological activity. This review covers some of the relevant and recent achievements in the biological, chemical and pharmacological activity of important indole derivatives in the areas of drug discovery and analysis. Molecules 2013-06-06 18 6 Review 10.3390/molecules18066620 6620 6662 1420-3049 2013-06-06 doi: 10.3390/molecules18066620 Nagendra Kaushik Neha Kaushik Pankaj Attri Naresh Kumar Chung Kim Akhilesh Verma Eun Choi http://www.mdpi.com/1420-3049/18/6/6608 The compound [Ni(L)(isoph)2][Ni(L)]·8H2O (1; L = C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane; H2-isoph = isophthalic acid) has been synthesized and structurally characterized. Complex 1 exhibits a geometrically symmetric core with a {4/6} coordination number set. The coordination environment around the Ni(1) ion is a distorted octahedron, while the geometry around the four-coordinate Ni(2) is depicted as square planar in 1D hydrogen-bonded infinite chain. The compound crystallizes in the triclinic system P-1 with a = 8.602(2), b = 10.684(7), c = 16.550(3) Å, a = 91.04(4), b = 94.09(2), g = 111.09(4)°, V = 1413.9(10) Å3, Z = 1. The cyclic voltammogram of 1 undergoes one-electron wave corresponding to NiII/NiI process. The electronic spectra, electrochemical and TGA behavior of the complex are significantly affected by the nature of the hexamethyltetraaza macrocycle and the axial isoph2− ligand. Molecules 2013-06-06 18 6 Article 10.3390/molecules18066608 6608 6619 1420-3049 2013-06-06 doi: 10.3390/molecules18066608 In-Taek Lim Ki-Young Choi http://www.mdpi.com/1420-3049/18/6/6597 Small sized magnetite iron oxide nanoparticles (Fe3O4-NPs) with were successfully synthesized on the surface of rice straw using the quick precipitation method in the absence of any heat treatment. Ferric chloride (FeCl3·6H2O), ferrous chloride (FeCl2·4H2O), sodium hydroxide (NaOH) and urea (CH4N2O) were used as Fe3O4-NPs precursors, reducing agent and stabilizer, respectively. The rice straw fibers were dispersed in deionized water, and then urea was added to the suspension, after that ferric and ferrous chloride were added to this mixture and stirred. After the absorption of iron ions on the surface layer of the fibers, the ions were reduced with NaOH by a quick precipitation method. The reaction was carried out under N2 gas. The mean diameter and standard deviation of metal oxide NPs synthesized in rice straw/Fe3O4 nanocomposites (NCs) were 9.93 ± 2.42 nm. The prepared rice straw/Fe3O4-NCS were characterized using powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) and Fourier transforms infrared spectroscopy (FT‒IR). The rice straw/Fe3O4-NCs prepared by this method have magnetic properties. Molecules 2013-06-05 18 6 Article 10.3390/molecules18066597 6597 6607 1420-3049 2013-06-05 doi: 10.3390/molecules18066597 Roshanak Khandanlou Mansor Ahmad Kamyar Shameli Katayoon Kalantari http://www.mdpi.com/1420-3049/18/6/6584 Non-steroidal anti-inflammatory drugs (NSAIDs) were shown to reduce the risk of colorectal cancer recurrence and are widely used to modulate inflammatory responses. Indomethacin is an NSAID. Herein, we reported that indomethacin can suppress cancer cell migration through its influence on the focal complexes formation. Furthermore, endothelial growth factor (EGF)-mediated Ca2+ influx was attenuated by indomethacin in a dose dependent manner. Our results identified a new mechanism of action for indomethacin: inhibition of calcium influx that is a key determinant of cancer cell migration. Molecules 2013-06-04 18 6 Article 10.3390/molecules18066584 6584 6596 1420-3049 2013-06-04 doi: 10.3390/molecules18066584 Yuh-Cherng Guo Che-Mai Chang Wen-Li Hsu Siou-Jin Chiu Yao-Ting Tsai Yii-Her Chou Ming-Feng Hou Jaw-Yan Wang Mei-Hsien Lee Ke-Li Tsai Wei-Chiao Chang http://www.mdpi.com/1420-3049/18/6/6573 Three novel C19 homolignans, taiwankadsurins D (1), E (2) and F (4), and two new C18 lignans kadsuphilins N (3) and O (5) were isolated from the aerial parts of Taiwanese medicinal plant Kadsura philippinensis. The structures of compounds 1–5 were determined by spectroscopic analyses, especially 2D NMR techniques. The structure of compound 5 was further confirmed by X-ray crystallographic analysis. Compounds 1 and 2 have a 3,4-{1'-[(Z)-2''-methoxy-2''-oxoethylidene]}-pentano(2,3-dihydrobenzo[b]furano)-3-(2'''-methoxycarbonyl-2'''-hydroxy-2''',3'-epoxide) skeleton. Molecules 2013-06-04 18 6 Article 10.3390/molecules18066573 6573 6583 1420-3049 2013-06-04 doi: 10.3390/molecules18066573 Yu-Chi Lin Yuan-Bin Cheng Chia-Ching Liaw I-Wen Lo Yao-Haur Kuo Michael Chiang Chang-Hung Chou Ya-Ching Shen http://www.mdpi.com/1420-3049/18/6/6550 Carbohydrates and derivatives (such as glycolipids, glycoproteins) are of critical importance for cell structure, metabolism and functions. The effects of carbohydrate and lipid metabolic imbalances most often cause health disorders and diseases. In this study, new carbohydrate-based nanobioconjugates were designed and synthesized at room temperature using a single-step aqueous route combining chitosan and acyl-modified chitosan with fluorescent inorganic nanoparticles. N-palmitoyl chitosan (C-Pal) was prepared aiming at altering the lipophilic behavior of chitosan (CHI), but also retaining its reasonable water solubility for potential biomedical applications. CHI and C-Pal were used for producing biofunctionalized CdS quantum dots (QDs) as colloidal water dispersions. Fourier transform infrared spectroscopy (FTIR), thermal analysis (TG/DSC), surface contact angle (SCA), and degree of swelling (DS) in phosphate buffer were used to characterize the carbohydrates. Additionally, UV-Visible spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), dynamic light scattering (DLS), scanning and transmission electron microscopy (SEM/TEM) were used to evaluate the precursors and nanobioconjugates produced. The FTIR spectra associated with the thermal analysis results have undoubtedly indicated the presence of N-palmitoyl groups “grafted” to the chitosan chain (C-Pal) which significantly altered its behavior towards water swelling and surface contact angle as compared to the unmodified chitosan. Furthermore, the results have evidenced that both CHI and C-Pal performed as capping ligands on nucleating and stabilizing colloidal CdS QDs with estimated average size below 3.5 nm and fluorescent activity in the visible range of the spectra. Therefore, an innovative “one-step” process was developed via room temperature aqueous colloidal chemistry for producing biofunctionalized quantum dots using water soluble carbohydrates tailored with amphiphilic behavior offering potential applications as fluorescent biomarkers in the investigation of glycoconjugates for the nutrition, biology, pharmaceutical, and medicine fields. Molecules 2013-06-04 18 6 Article 10.3390/molecules18066550 6550 6572 1420-3049 2013-06-04 doi: 10.3390/molecules18066550 Joyce Santos Alexandra Mansur Herman Mansur http://www.mdpi.com/1420-3049/18/6/6532 The main objective of this work was the incorporation of reactive isocyanate groups into chitin and chitosan in order to effectively use the products as reactive thickening agents in castor oil. The resulting gel-like dispersions could be potentially used as biodegradable lubricating greases. Three different NCO–functionalized polymers were obtained: two of them by promoting the reaction of chitosan with 1,6-hexamethylene diisocyanate (HMDI), and the other by using chitin instead of chitosan. These polymers were characterized through 1H-NMR, FTIR and thermogravimetric analysis (TGA). Thermal and rheological behaviours of the oleogels prepared by dispersing these polymers in castor oil were studied by means of TGA and small-amplitude oscillatory shear (SAOS) measurements. The evolution and values of the linear viscoelasticity functions with frequency for –NCO–functionalized chitosan- and chitin-based oleogels are quite similar to those found for standard lubricating greases. In relation to long-term stability of these oleogels, no phase separation was observed and the values of viscoelastic functions increase significantly during the first seven days of ageing, and then remain almost constant. TGA analysis showed that the degradation temperature of the resulting oleogels is higher than that found for traditional lubricating greases. Molecules 2013-06-03 18 6 Article 10.3390/molecules18066532 6532 6549 1420-3049 2013-06-03 doi: 10.3390/molecules18066532 Rocío Gallego Jesús Arteaga Concepción Valencia José Franco http://www.mdpi.com/1420-3049/18/6/6521 This study develops a new solvent-compatible microfluidic chip based on phenol formaldehyde resin (PFR). In addition to its solvent-resistant characteristics, this microfluidic platform also features easy fabrication, organization, decomposition for cleaning, and reusability compared with conventional chips. Both solvent-dependent (e.g., polycaprolactone) and nonsolvent-dependent (e.g., chitosan) microparticles were successfully prepared. The size of emulsion droplets could be easily adjusted by tuning the flow rates of the dispersed/continuous phases. After evaporation, polycaprolactone microparticles ranging from 29.3 to 62.7 μm and chitosan microparticles ranging from 215.5 to 566.3 μm were obtained with a 10% relative standard deviation in size. The proposed PFR microfluidic platform has the advantages of active control of the particle size with a narrow size distribution as well as a simple and low cost process with a high throughput. Molecules 2013-06-03 18 6 Article 10.3390/molecules18066521 6521 6531 1420-3049 2013-06-03 doi: 10.3390/molecules18066521 Yung-Sheng Lin Chih-Hui Yang Chin-Tung Wu Alexandru Grumezescu Chih-Yu Wang Wan-Chen Hsieh Szu-Yu Chen Keng-Shiang Huang http://www.mdpi.com/1420-3049/18/6/6504 Pectinate gel beads containing Thai mango seed kernel extract (MSKE, cultivar ‘Fahlun’) were developed and characterised for the purpose of colon-targeted delivery. The MSKE-loaded pectinate beads were prepared using ionotropic gelation with varying pectin-to-MSKE ratios, MSKE concentrations, and concentrations of two cross-linkers (calcium chloride and zinc acetate). The formulated beads were spherical in shape and ranged in size between 1.13 mm and 1.88 mm. Zinc-pectinate (ZPG) beads containing high amounts of MSKE showed complete entrapment efficiency (EE) of MSKE (100%), while calcium-pectinate (CPG) beads demonstrated 70% EE. The in vitro release tests indicated that MSKE-loaded CPG beads were unstable in both simulated gastric medium (SGM) and simulated intestinal medium (SIM), while MSKE-loaded ZPG beads were stable in SIM but unable to prevent the release of MSKE in SGM. The protection of ZPG beads with gastro-resistant capsules (Eudragit® L 100-55) resulted in stability in both SGM and SIM; they disintegrated immediately in simulated colonic medium containing pectinolytic enzymes. MSKE-loaded ZPG beads were stable at 4, 25 and 45 °C during the study period of four months. The present study revealed that ZPG beads in enteric-coated capsules might be a promising carrier for delivering MSKE to the colon. Molecules 2013-06-03 18 6 Article 10.3390/molecules18066504 6504 6520 1420-3049 2013-06-03 doi: 10.3390/molecules18066504 Saruth Nithitanakool Pimolpan Pithayanukul Sandrine Bourgeois Hatem Fessi Rapepol Bavovada http://www.mdpi.com/1420-3049/18/6/6491 Over the years, the development of targeted medicines has made significant achievements. As a typical example, receptor tyrosine kinases (RTK) inhibitors have become important chemotherapy drugs for a variety of cancers. However, the effectiveness of these agents is always hindered by poor response rates and acquired drug resistance. In order to overcome these limitations, several dual-targeted inhibitors with quinazoline core were designed and synthesized. Though these compounds can simultaneously inhibit histone deacetylases (HDAC) as well as RTK, the structure-activity relationship (SAR) is still not clear enough. To further explore this type of dual-targeted inhibitors, a new class of quinazoline derivatives were designed and synthesized. Their activity evaluations include in vitro inhibitory activity of HDAC, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). The SAR study indicated that the introduction of polar group such as hydroxamate on the 4-position of the quinazoline core is more likely to provide a potent HDACi/HER2i hybrid rather than HDACi/EGFRi molecule. Molecules 2013-06-03 18 6 Article 10.3390/molecules18066491 6491 6503 1420-3049 2013-06-03 doi: 10.3390/molecules18066491 Xuan Zhang Mingbo Su Yi Chen Jia Li Wei Lu http://www.mdpi.com/1420-3049/18/6/6469 Molecular imaging—and especially Positron Emission Tomography (PET)—is of increasing importance for the diagnosis of various diseases and thus is experiencing increasing dissemination. Consequently, there is a growing demand for appropriate PET tracers which allow for a specific accumulation in the target structure as well as its visualization and exhibit decay characteristics matching their in vivo pharmacokinetics. To meet this demand, the development of new targeting vectors as well as the use of uncommon radionuclides becomes increasingly important. Uncommon nuclides in this regard enable the utilization of various selectively accumulating bioactive molecules such as peptides, antibodies, their fragments, other proteins and artificial structures for PET imaging in personalized medicine. Among these radionuclides, 89Zr (t1/2 = 3.27 days and mean Eβ+ = 0.389 MeV) has attracted increasing attention within the last years due to its favorably long half-life, which enables imaging at late time-points, being especially favorable in case of slowly-accumulating targeting vectors. This review outlines the recent developments in the field of 89Zr-labeled bioactive molecules, their potential and application in PET imaging and beyond, as well as remaining challenges. Molecules 2013-06-03 18 6 Review 10.3390/molecules18066469 6469 6490 1420-3049 2013-06-03 doi: 10.3390/molecules18066469 Gabriel Fischer Uwe Seibold Ralf Schirrmacher Björn Wängler Carmen Wängler http://www.mdpi.com/1420-3049/18/6/6455 It is well known that overwhelming neutrophil activation is closely related to acute and chronic inflammatory injuries. Formyl peptide receptor 1 (FPR1) plays an important role in activation of neutrophils and may represent a potent therapeutic target in inflammatory diseases. In the present study, we demonstrated that IA-LBI07-1 (IA), an extract of bioactive secondary metabolites from a marine Bacillus sp., has anti-inflammatory effects in human neutrophils. IA significantly inhibited superoxide generation and elastase release in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated neutrophils, but failed to suppress the cell responses activated by non-FPR1 agonists. IA did not alter superoxide production and elastase activity in cell-free systems. IA also attenuated the downstream signaling from FPR1, such as the Ca2+, MAP kinases and AKT pathways. In addition, IA inhibited the binding of N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein, a fluorescent analogue of FMLP, to FPR1 in human neutrophils and FPR1-transfected HEK293 cells. Taken together, these results show that the anti-inflammatory effects of IA in human neutrophils are through the inhibition of FPR1. Also, our data suggest that IA may have therapeutic potential to decrease tissue damage induced by human neutrophils. Molecules 2013-06-03 18 6 Article 10.3390/molecules18066455 6455 6468 1420-3049 2013-06-03 doi: 10.3390/molecules18066455 Shun-Chin Yang Chwan-Fwu Lin Wen-Yi Chang Jimmy Kuo Yin-Ting Huang Pei-Jen Chung Tsong-Long Hwang http://www.mdpi.com/1420-3049/18/6/6439 The inhibitory activity of isoferulic acid (IFA) on fructose- and glucose-mediated protein glycation and oxidation of bovine serum albumin (BSA) was investigated. Our data showed that IFA (1.25–5 mM) inhibited the formation of fluorescent advanced glycation end products (AGEs) and non-fluorescent AGE [Nε-(carboxymethyl) lysine: CML], as well as the level of fructosamine. IFA also prevented protein oxidation of BSA indicated by decreasing protein carbonyl formation and protein thiol modification. Furthermore, IFA suppressed the formation of β-cross amyloid structures of BSA. Therefore, IFA might be a new promising anti-glycation agent for the prevention of diabetic complications via inhibition of AGEs formation and oxidation-dependent protein damage. Molecules 2013-05-30 18 6 Article 10.3390/molecules18066439 6439 6454 1420-3049 2013-05-30 doi: 10.3390/molecules18066439 Aramsri Meeprom Weerachat Sompong Catherine Chan Sirichai Adisakwattana http://www.mdpi.com/1420-3049/18/6/6425 d-Glucosamine (DG) was conjugated to a core-cross linked polymeric micelle (CCPM) system equipped with both a near-infrared fluorophore (NIRF) and a gamma emitter (111In). The resultant nano-scale tumor-targeting imaging tracer, 111In-DG-NIRF-CCPM, selectively accumulated in a human epithelial carcinoma A-431 xenograft model in mice. At 24 hrs post injection, the tumor uptake was 2.62 ± 0.80 % of the injected dose per gram of tissue (%ID/g). Tumors were clearly delineated in both single-photon emission computed tomography (SPECT) and optical imaging. The results suggest that the prepared imaging tracer is a promising agent for tumor diagnosis. Molecules 2013-05-30 18 6 Article 10.3390/molecules18066425 6425 6438 1420-3049 2013-05-30 doi: 10.3390/molecules18066425 Hua Zhu Jun Zhao Xinfeng Lin Ye Hong Chun Li Zhi Yang http://www.mdpi.com/1420-3049/18/6/6408 In the past 20 years, synthetic combinatorial methods have fundamentally advanced the ability to synthesize and screen large numbers of compounds for drug discovery and basic research. Mixture-based libraries and positional scanning deconvolution combine two approaches for the rapid identification of specific scaffolds and active ligands. Here we present a quantitative assessment of the screening of 32 positional scanning libraries in the identification of highly specific and selective ligands for two formylpeptide receptors. We also compare and contrast two mixture-based library approaches using a mathematical model to facilitate the selection of active scaffolds and libraries to be pursued for further evaluation. The flexibility demonstrated in the differently formatted mixture-based libraries allows for their screening in a wide range of assays. Molecules 2013-05-30 18 6 Article 10.3390/molecules18066408 6408 6424 1420-3049 2013-05-30 doi: 10.3390/molecules18066408 Radleigh Santos Jon Appel Marc Giulianotti Bruce Edwards Larry Sklar Richard Houghten Clemencia Pinilla http://www.mdpi.com/1420-3049/18/6/6383 A series of metallosupramolecular [Fe2L3](BF4)4 “click” cylinders have been synthesized in excellent yields (90%–95%) from [Fe(H2O)6](BF4)2 and bis(bidentate) pyridyl-1,2,3-triazole ligands. All complexes were characterized by elemental analysis, IR, UV-vis, 1H-, 13C- and DOSY-NMR spectroscopies and, in four cases, the structures confirmed by X-ray crystallography. Molecular modeling indicated that some of these “click” complexes were of similar size and shape to related biologically active pyridylimine-based iron(II) helicates and suggested that the “click” complexes may bind both duplex and triplex DNA. Cell-based agarose diffusion assays showed that the metallosupramolecular [Fe2L3](BF4)4 “click” cylinders display no antifungal activity against S. cerevisiae. This observed lack of antifungal activity appears to be due to the poor stability of the “click” complexes in DMSO and biological media. Molecules 2013-05-29 18 6 Article 10.3390/molecules18066383 6383 6407 1420-3049 2013-05-29 doi: 10.3390/molecules18066383 Sreedhar Vellas James Lewis Madhu Shankar Alia Sagatova Joel Tyndall Brian Monk Christopher Fitchett Lyall Hanton James Crowley http://www.mdpi.com/1420-3049/18/6/6366 The work reported herein describes the synthesis and the assessment of the trypanocidal activity of thirteen new 1,2,4-triazole-3-thiones obtained from natural piperine, the main constituent of the dry fruits of Piper nigrum. It is part of a research program aiming to use abundant and easily available natural products as starting materials for the design and synthesis of new molecules potentially useful as antiparasitic drugs. The variously substituted triazole derivatives were synthesized from the natural amide in four steps with the use of microwave irradiation on overall yields ranging from 32% to 51%. The cyclohexyl substituted derivative showed the best trypanocidal profile on proliferative forms of Trypanosoma cruzi (Y strain), with IC50s = 18.3 and 8.87 mM against epimastigotes and amastigotes, respectively. Molecules 2013-05-29 18 6 Article 10.3390/molecules18066366 6366 6382 1420-3049 2013-05-29 doi: 10.3390/molecules18066366 Tatiany Franklim Leonardo Freire-de-Lima Julliana de Nazareth Sá Diniz José Previato Rosane Castro Lucia Mendonça-Previato Marco de Lima http://www.mdpi.com/1420-3049/18/6/6356 The aim of this study was to investigate the total phenolic content, total flavonoid contents, antioxidant activity and antimicrobial activity of ethanolic extract from stems (S) and leaves (L) of Impatiens balsamina L. (Balsaminaceae), which were harvested in Korea on March 10, 2011 (S1 and L1), May 14, 2011 (S2 and L2), and July 5, 2011 (S3 and L3), respectively. Our results revealed that the total phenolic (79.55–103.94 mg CE/g extract) and flavonoid (57.43–104.28 mg QE/g extract) contents of leaf extract were higher (p < 0.01) than those of stem extract. Leaf extracts (L1, L2, and L3) exhibited stronger (p < 0.01) free radical scavenging activity (66.06, 63.71, and 72.19%, respectively) than that of the positive control. In terms of antimicrobial activity, leaf extracts showed higher inhibitory effects against microorganisms than those of stem extracts (S1, S2, and S3). Among the leaf extracts at different harvest times, L3 showed the greatest antimicrobial activity against both Gram negative and Gram positive strains. From these results, the leaf extract from I. balsamina L. might be a valuable bioactive resource, and would seem to be applicable as a natural antioxidant in food preservation. Molecules 2013-05-29 18 6 Article 10.3390/molecules18066356 6356 6365 1420-3049 2013-05-29 doi: 10.3390/molecules18066356 Suk-Nam Kang Young-Min Goo Mi-Ra Yang Rashid Ibrahim Jae-Hyeon Cho Il-Suk Kim Ok-Hwan Lee http://www.mdpi.com/1420-3049/18/6/6311 Cyclooxygenase-2 (COX-2) is a key player in inflammation. Its overexpression is directly associated with various inflammatory diseases and, additionally, with several processes of carcinogenesis. The development of new selective COX-2 inhibitors (COXIBs) for use in cancer treatment is in the focus of the medicinal chemistry research field. For this purpose, a set of methods is available to determine COX-2 expression and activity in vitro and ex vivo but it is still a problem to functionally characterize COX-2 in vivo. This review focusses on imaging agents targeting COX-2 which have been developed for positron emission tomography (PET) and single photon emission computed tomography (SPECT) since 2005. The literature reveals that different radiochemical methods are available to synthesize COXIBs radiolabeled with fluorine-18, carbon-11, and isotopes of radioiodine. Unfortunately, most of the compounds tested did not show sufficient stability in vivo due to de[18F]fluorination or de[11C]methylation or they failed to bind specifically in the target region. So, suitable stability in vivo, matching lipophilicity for the target compartment and both high affinity and selectivity for COX-2 were identified as prominent criteria for radiotracer development. Up to now, it is not clear what approach and which model is the most suited to evaluate COX-2 targeting imaging agents in vivo. However, for proof of principle it has been shown that some radiolabeled compounds can bind specifically in COX-2 overexpressing tissue which gives hope for future work in this field. Molecules 2013-05-29 18 6 Review 10.3390/molecules18066311 6311 6355 1420-3049 2013-05-29 doi: 10.3390/molecules18066311 Markus Laube Torsten Kniess Jens Pietzsch http://www.mdpi.com/1420-3049/18/6/6298 Fucoxanthin is one of the most abundant carotenoids and possesses a number of beneficial medicinal qualities which include its anti-oxidant, anti-obesity and anti-cancer properties. In this study, the photostability of fucoxanthin in extracts with different chemical profiles was studied. The extracts were obtained from Undaria pinnatifida, a seaweed rich in this carotenoid, using conventional liquid solvent extraction procedures and the QuEChERS method. All the extracts contained all-trans-fucoxanthin as the major compound. Conventional procedures produced a fucoxanthin purity of lower than 50%, whereas after liquid-liquid partition, PSA cleanup, and PSA and GCB cleanup (QuEChERS method) fucoxanthin purity increased to 70%, 86%, and 94%, respectively. Although in the acetone extract the initial content of fucoxanthin was the highest, results demonstrate that coextractives play an important role in enhancing the rate of photodegradation. After light exposure, the conventional extracts lost around 90% of the initial fucoxanthin content. On the other hand, the extracts obtained by the QuEChERS method showed significantly higher light stability than the conventional extracts. These results suggest that the QuEChERS method could be used and further improved to obtain more purified and stable extracts for fucoxanthin from U. pinnatifida. Molecules 2013-05-29 18 6 Article 10.3390/molecules18066298 6298 6310 1420-3049 2013-05-29 doi: 10.3390/molecules18066298 Anna Piovan Roberta Seraglia Bruno Bresin Rosy Caniato Raffaella Filippini http://www.mdpi.com/1420-3049/18/6/6281 A new indole alkaloid, 12-hydroxy-N-acetyl-21(N)-dehydroplumeran-18-oic acid (13), and 11 known indole alkaloids: 3,4,5,6-tetradehydro-β-yohimbine (3), 19(E)-hunteracine (4), b-yohimbine (5), yohimbine (6), 19,20-dehydro-17-a-yohimbine (7), uleine (10), 20-epi-dasycarpidone (11), olivacine (8), 20-epi-N-nor-dasycarpidone (14), N-demethyluleine (15) and 20(E)-nor-subincanadine E (12) and a boonein d-lactone 9, ursolic acid (1) and 1D,1O-methyl-chiro-inositol (2) were isolated from the EtOH extracts of different parts of Aspidosperma ulei Markgr. (Apocynaceae). Identification and structural elucidation were based on IR, MS, 1H- and 13C-NMR spectral data and comparison to literature data. The antiplasmodial and antimalarial activity of 1, 5, 6, 8, 10 and 15 has been previously evaluated and 1 and 10 have important in vitro and in vivo antimalarial properties according to patent and/or scientific literature. With the aim of discovering new antiplasmodial indole alkaloids, 3, 4, 11, 12 and 13 were evaluated for in vitro inhibition against the multi-drug resistant K1 strain of the human malaria parasite Plasmodium falciparum. IC50 values of 14.0 (39.9), 4.5 (16.7) and 14.5 (54.3) mg/mL (mM) were determined for 3, 11 and 12, respectively. Inhibitory activity of 3, 4, 11, 12 and 13 was evaluated against NIH3T3 murine fibroblasts. None of these compounds exhibited toxicity to fibroblasts (IC50 > 50 mg/mL). Of the five compounds screened for in vitro antiplasmodial activity, only 11 was active. Molecules 2013-05-29 18 6 Article 10.3390/molecules18066281 6281 6297 1420-3049 2013-05-29 doi: 10.3390/molecules18066281 Zelina dos Santos Torres Edilberto Silveira Luiz Rocha e Silva Emerson Lima Marne de Vasconcellos Daniel de Andrade Uchoa Raimundo Filho Adrian Pohlit http://www.mdpi.com/1420-3049/18/6/6269 Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs) as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO3 relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9–35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNC-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals. Molecules 2013-05-28 18 6 Article 10.3390/molecules18066269 6269 6280 1420-3049 2013-05-28 doi: 10.3390/molecules18066269 Susan Azizi Mansor Ahmad Mohd Hussein Nor Ibrahim http://www.mdpi.com/1420-3049/18/6/6230 Macrocyclic scaffolds are commonly found in bioactive natural products and pharmaceutical molecules. So far, a large number of macrocyclic natural products have been isolated and synthesized. The construction of macrocycles is generally considered as a crucial and challenging step in the synthesis of macrocyclic natural products. Over the last several decades, numerous efforts have been undertaken toward the synthesis of complex naturally occurring macrocycles and great progresses have been made to advance the field of total synthesis. The commonly used synthetic methodologies toward macrocyclization include macrolactonization, macrolactamization, transition metal-catalyzed cross coupling, ring-closing metathesis, and click reaction, among others. Selected recent examples of macrocyclic synthesis of natural products and druglike macrocycles with significant biological relevance are highlighted in each class. The primary goal of this review is to summarize currently used macrocyclic drugs, highlight the therapeutic potential of this underexplored drug class and outline the general synthetic methodologies for the synthesis of macrocycles. Molecules 2013-05-24 18 6 Review 10.3390/molecules18066230 6230 6268 1420-3049 2013-05-24 doi: 10.3390/molecules18066230 Xufen Yu Dianqing Sun http://www.mdpi.com/1420-3049/18/6/6215 Calophyllum brasiliense is a rich source of bioactive coumarins, xanthones and biflavonoids. The aim of the study was to compare the phenol contents and the antioxidant activity of C. brasiliense extracts obtained by conventional and supercritical fluid extraction (SFE) methods, as well as the quantification of crude extracts and (−)-mammea A/BB yields. Dichloromethane and hexane were used as solvents for the conventional extractions and SFE was developed using supercritical CO2; the kinetic curves were modeled using a second-order empirical model. The dichloromethane extract presented the best total yield, although it showed the lowest content of (−)-mammea A/BB. The concentration of the coumarin was considerably higher in extracts obtained by the supercritical fluid method and a higher antioxidant activity was assigned to extracts obtained by this technique. Concerning the total phenolic contents, both the dichloro-methane and the supercritical extractions produced satisfactory amounts. The SFE method proved to be more promising than conventional methods. Molecules 2013-05-24 18 6 Article 10.3390/molecules18066215 6215 6229 1420-3049 2013-05-24 doi: 10.3390/molecules18066215 Renata Gonçalves Caroline Lemos Ivana Leal Celso Nakamura Diógenes Cortez Edson da Silva Vladimir Cabral Lúcio Cardozo-Filho http://www.mdpi.com/1420-3049/18/6/6193 Two modified chitosan derivatives were prepared in order to compare their adsorption properties for Hg(II) removal from aqueous solutions. The one chitosan adsorbent (CS) is only cross–linked with glutaraldehyde, while the other (CSm), which is magnetic, is cross-linked with glutaraldehyde and functionalized with magnetic nanoparticles (Fe3O4). Many possible interactions between materials and Hg(II) were observed after adsorption and explained via characterization with various techniques (SEM/EDAX, FTIR, XRD, DTG, DTA, VSM, swelling tests). The adsorption evaluation was done studying various parameters as the effect of pH (optimum value 5 for adsorption and 2 for desorption), contact time (fitting to pseudo–first, –second order and Elovich equations), temperature (isotherms at 25, 45, 65 °C), in line with a brief thermodynamic analysis (ΔG0 < 0, ΔH0 > 0, ΔS0 > 0). The maximum adsorption capacity (fitting with Langmuir and Freundlich model) of CS and CSm at 25 °C was 145 and 152 mg/g, respectively. The reuse ability of the adsorbents prepared was confirmed with sequential cycles of adsorption-desorption. Molecules 2013-05-24 18 6 Article 10.3390/molecules18066193 6193 6214 1420-3049 2013-05-24 doi: 10.3390/molecules18066193 George Kyzas Eleni Deliyanni http://www.mdpi.com/1420-3049/18/6/6173 The palladium (II)-catalysed reactions of alkenols and aminoalkenols such as oxycarbonylations or bicyclisations are powerful methods for the construction of oxygen and nitrogen-containing heterocyclic compounds. This review highlights recent progress in the development of the asymmetric palladium(II)-catalysed Wacker-type cyclisations of unsaturated polyols and aminoalcohols. The scope, limitations, and applications of these reactions are presented. Molecules 2013-05-24 18 6 Review 10.3390/molecules18066173 6173 6192 1420-3049 2013-05-24 doi: 10.3390/molecules18066173 Jana Doháňošová Tibor Gracza http://www.mdpi.com/1420-3049/18/6/6161 Oregano and thyme essential oils are used for therapeutic, aromatic and gastronomic purposes due to their richness in active substances, like carvacrol; however, the effects of the latter on the central nervous system have been poorly investigated. The aim of our study was to define the effects of carvacrol on brain neurochemistry and behavioural outcome in rats. Biogenic amine content in the prefrontal cortex and hippocampus after chronic or acute oral carvacrol administration was measured. Animals were assessed by a forced swimming test. Carvacrol, administered for seven consecutive days (12.5 mg/kg p.o.), was able to increase dopamine and serotonin levels in the prefrontal cortex and hippocampus. When single doses were used (150 and 450 mg/kg p.o.), dopamine content was increased in the prefrontal cortex at both dose levels. On the contrary, a significant dopamine reduction in hippocampus of animals treated with 450 mg/kg of carvacrol was found. Acute carvacrol administration only significantly reduced serotonin content in either the prefrontal cortex or in the hippocampus at the highest dose. Moreover, acute carvacrol was ineffective in producing changes in the forced swimming test. Our data suggest that carvacrol is a brain-active molecule that clearly influences neuronal activity through modulation of neurotransmitters. If regularly ingested in low concentrations, it might determine feelings of well-being and could possibly have positive reinforcer effects. Molecules 2013-05-24 18 6 Article 10.3390/molecules18066161 6161 6172 1420-3049 2013-05-24 doi: 10.3390/molecules18066161 Margherita Zotti Marilena Colaianna Maria Morgese Paolo Tucci Stefania Schiavone Pinarosa Avato Luigia Trabace http://www.mdpi.com/1420-3049/18/6/6153 A new 8,4¢-oxyneolignane glucoside 1 has been isolated from the stems of Dendrobium aurantiacum var. denneanum together with six known phenolic glucosides 2-7. The structure of the new compound, including its absolute configuration, was determined by spectroscopic and chemical methods as (–)-(7S,8R,7¢E)-4-hydroxy-3,3¢,5,5¢-tetramethoxy-8,4¢-oxyneolign-7¢-ene-7,9,9¢-triol 7,9¢-bis-O-β-D-glucopyranoside (1). In the in vitro assays, compound 1 and (-)-syringaresinol-4,4¢-bis-O-β-D-glucopyranoside (2) showed evident activity against glutamate-induced neurotoxicity in PC12 cells. Shashenoside I (4) showed a selective cytotoxic activity with the IC50 value of 4.17 μM against the acute myeloid leukemia cell line MV4-11, while it was inactive against 10 other human tumor cell lines. Molecules 2013-05-23 18 6 Article 10.3390/molecules18066153 6153 6160 1420-3049 2013-05-23 doi: 10.3390/molecules18066153 Liang Xiong Zhi-Xing Cao Cheng Peng Xiao-Hong Li Xiao-Fang Xie Ting-Mo Zhang Qin-Mei Zhou Lian Yang Li Guo http://www.mdpi.com/1420-3049/18/6/6142 An efficient one-pot synthesis of novel β-amino acid derivatives containing a thiadiazole moiety was developed using a chiral squaramide cinchona alkaloid as organocatalyst. The reactions afforded chiral β-amino acid derivatives in moderate yields and with moderate to excellent enantioselectivities. The present study demonstrated for the first time the use of a Mannich reaction catalyzed by a chiral bifunctional organocatalyst for the one-pot synthesis of novel β-amino acid derivatives bearing a 1,3,4-thiadiazole moiety on nitrogen. Molecules 2013-05-23 18 6 Article 10.3390/molecules18066142 6142 6152 1420-3049 2013-05-23 doi: 10.3390/molecules18066142 Kankan Zhang Xueping Liang Ming He Jian Wu Yuping Zhang Wei Xue Linhong Jin Song Yang Deyu Hu http://www.mdpi.com/1420-3049/18/6/6128 Novel antioxidants have been synthesized and characterized by their chemical properties as antioxidants with high superoxide scavenging activity. (2R,3R)-diphenylethylenediamine is a spacer in antioxidants, and we synthesized targets 11a and 11b by conjugation with o-hydroquinone and p-hydroquinone at the two N-termini, respectively. Superoxide scavenging activities of the plant flavonoid-like 11a and 11b were compared with those of known antioxidants, and shown to increase in the following order: curcumin << ascorbic acid < Trolox < ()-epicatechin < 11a < quercetin ≤ 11b . Compound 11a also formed a solvated 11a–metal complex with metal ions. The 11a–Cu2+ complex was shown to have higher superoxide scavenging activity than that of 11a, 11b, Cu2+, and the 11a–Al3+ and 11a–La3+ complexes, whereas the 11a–Al3+ complex increased rather than decreased superoxide levels. The 11a–Al3+ complex did not abstract one electron from the SOMO of O2−. since the HOMO and LUMO phases of Al3+ do not exist in the center of the 11a–Al3+ complex. However, the SOMO of the 11a–Cu2+ complex distributed in the center of Cu2+ may abstract one electron from the SOMO of O2−.. These results suggest that 11a and 11b are powerful antioxidants. Molecules 2013-05-23 18 6 Article 10.3390/molecules18066128 6128 6141 1420-3049 2013-05-23 doi: 10.3390/molecules18066128 Shigeki Kobayashi Sachi Kanai http://www.mdpi.com/1420-3049/18/5/6113 Sophoricoside exhibits numerous pharmacological effects, including anti- inflammatory and anti-cancer actions, yet the exact mechanism that accounts for the anti-allergic effects of sophoricoside is not completely understood. The aim of the present study was to elucidate whether and how sophoricoside modulates the mast cell-mediated allergic inflammation in vitro and in vivo. We investigated the pharmacological effects of sophoricoside on both compound 48/80 or histamine-induced scratching behaviors and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in mice. Additionally, to find a possible explanation for the anti-inflammatory effects of sophoricoside, we evaluated the effects of sophoricoside on the production of histamine and inflammatory cytokines and activation of nuclear factor-κB (NF-κB) and caspase-1 in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated human mast cells (HMC-1). The finding of this study demonstrated that sophoricoside reduced compound 48/80 or histamine-induced scratching behaviors and DNCB-induced atopic dermatitis in mice. Additionally, sophoricoside inhibited the production of inflammatory cytokines as well as the activation of NF-κB and caspase-1 in stimulated HMC-1. Collectively, the findings of this study provide us with novel insights into the pharmacological actions of sophoricoside as a potential molecule for use in the treatment of allergic inflammation diseases. Molecules 2013-05-22 18 5 Article 10.3390/molecules18056113 6113 6127 1420-3049 2013-05-22 doi: 10.3390/molecules18056113 Su-Jin Kim Gil-Yong Lee Ji-Wook Jung Sa-Rang Oh Eun-Mi Ahn Sung-Hoon Kim Seung-Heon Hong Jae-Young Um http://www.mdpi.com/1420-3049/18/5/6101 The two step synthesis of a new bolaamphiphile derived from alkenyl l-rhamnosides was described. The general synthetic strategy of bolaamphiphiles derived from l-rhamnose was based on a previous work describing the synthesis of bolaamphiphiles derived from d-xylose. The conformational properties of this new compound were investigated by FTIR spectroscopy in an aqueous film in order to obtain a reference for further studies about the membrane-interacting properties. Moreover, the surface activity of this new bolaamphiphile was analyzed by Langmuir balance technology and was compared with that of the analogous bolaamphiphile derived from alkenyl D-xylosides. The findings indicate that the rhamnoside-based bolaform has an increased surface activity and a better ability to form aggregates than xyloside-based one. Molecules 2013-05-22 18 5 Short Note 10.3390/molecules18056101 6101 6112 1420-3049 2013-05-22 doi: 10.3390/molecules18056101 Sylvain Gatard Mehmet Nasir Magali Deleu Nadia Klai Vincent Legrand Sandrine Bouquillon http://www.mdpi.com/1420-3049/18/5/6092 Six biflavonoids were isolated from G. madruno, one of which, 7''-O-(6''''-acetyl)-glucoside of morelloflavone, is a new compound identified on the basis of 1D, 2D NMR (HMQC and HMBC) spectroscopic methods and chemical evidence. The antioxidant activity of the biflavonoids against low-density lipoprotein (LDL) peroxidation induced with Cu2+, was studied by means of a TBARS assay. The antioxidant potential of a biflavonoid fraction (BF) was also evaluated and correlated with its biflavonoid content. The flavanone-(3→8'')-flavone biflavonoids displayed antioxidant activity, particularly morelloflavone, which was significantly more potent than quercetin, with a CE50 of 12.36 μg/mL. Lipid peroxidation, was also significantly reduced in the presence of the BF (EC50 = 11.85 μg/mL). These results suggest that the BF is an excellent antioxidant. Molecules 2013-05-22 18 5 Article 10.3390/molecules18056092 6092 6100 1420-3049 2013-05-22 doi: 10.3390/molecules18056092 Edison Osorio Julián Londoño Jaume Bastida http://www.mdpi.com/1420-3049/18/5/6057 In order to find novel antiviral agents, a series of allosteric MEK1 inhibitors were designed and synthesized. Based on docking results, multiple optimizations were made on the coumarin scaffold. Some of the derivatives showed excellent MEK1 binding affinity in the appropriate enzymatic assays and displayed obvious inhibitory effects on the ERK pathway in a cellular assay. These compounds also significantly inhibited virus (EV71) replication in HEK293 and RD cells. Several compounds showed potential as agents for the treatment of viral infective diseases, with the most potent compound 18 showing an IC50 value of 54.57 nM in the MEK1 binding assay. Molecules 2013-05-21 18 5 Article 10.3390/molecules18056057 6057 6091 1420-3049 2013-05-21 doi: 10.3390/molecules18056057 Chao Wang Hao Zhang Fengrong Xu Yan Niu Yun Wu Xin Wang Yihong Peng Jing Sun Lei Liang Ping Xu http://www.mdpi.com/1420-3049/18/5/6035 The aim of this work was to gain insight into the effect of food formulation on aroma release and perception, both of which playing an important role in food appreciation. The quality and quantity of retronasal aroma released during food consumption affect the exposure time of olfactory receptors to aroma stimuli, which can influence nutritional and hedonic characteristics, as well as consumption behaviors. In yogurts, fruit preparation formulation can be a key factor to modulate aroma stimulation. In this context, the impact of size and hardness of fruit pieces in fat-free pear yogurts was studied. Proton Transfer Reaction-Mass Spectrometry (PTR-MS) was used to allow sensitive and on-line monitoring of volatile odorous compound release in the breath during consumption. In parallel, a trained panel used sensory profile and Temporal Dominance of Sensations (TDS) methods to characterize yogurt sensory properties and their dynamic changes during consumption. Results showed that the size of pear pieces had few effects on aroma release and perception of yogurts, whereas fruit hardness significantly influenced them. Despite the fact that yogurts presented short and similar residence times in the mouth, this study showed that fruit preparation could be an interesting formulation factor to enhance exposure time to stimuli and thus modify food consumption behaviors. These results could be taken into account to formulate new products that integrate both nutritional and sensory criteria. Molecules 2013-05-21 18 5 Article 10.3390/molecules18056035 6035 6056 1420-3049 2013-05-21 doi: 10.3390/molecules18056035 Joshua Mesurolle Anne Saint-Eve Isabelle Déléris Isabelle Souchon http://www.mdpi.com/1420-3049/18/5/6021 D-Glucopyranose-derived and L-idopyranose-derived piperidine nitrones were synthesized in good overall yields through six-step reaction sequence starting from readily available 2,3,4,6-tetra-O-benzyl-D-glucopyranose. The method is efficient and could be general for the synthesis of aldohexose-derived piperidine nitrones which are precursors of piperidine iminosugars. Molecules 2013-05-21 18 5 Article 10.3390/molecules18056021 6021 6034 1420-3049 2013-05-21 doi: 10.3390/molecules18056021 Hui Zhao Wen-Bo Zhao Jian-She Zhu Yue-Mei Jia Chu-Yi Yu http://www.mdpi.com/1420-3049/18/5/6008 Hen egg-white lysozyme (LSZ) is currently used in the food industry to limit the proliferation of lactic acid bacteria spoilage in the production of wine and beer, and to inhibit butyric acid fermentation in hard and extra hard cheeses (late blowing) caused by the outgrowth of clostridial spores. The aim of this work was to evaluate how the enzyme activity in commercial preparations correlates to the enzyme concentration and can be affected by the presence of process-related impurities. Different analytical approaches, including turbidimetric assay, SDS-PAGE and HPLC were used to analyse 17 commercial preparations of LSZ marketed in different countries. The HPLC method adopted by ISO allowed the true LSZ concentration to be determined with accuracy. The turbidimetric assay was the most suitable method to evaluate LSZ activity, whereas SDS-PAGE allowed the presence of other egg proteins, which are potential allergens, to be detected. The analytical results showed that the purity of commercially available enzyme preparations can vary significantly, and evidenced the effectiveness of combining different analytical approaches in this type of control. Molecules 2013-05-21 18 5 Article 10.3390/molecules18056008 6008 6020 1420-3049 2013-05-21 doi: 10.3390/molecules18056008 Milena Brasca Stefano Morandi Tiziana Silvetti Veronica Rosi Stefano Cattaneo Luisa Pellegrino http://www.mdpi.com/1420-3049/18/5/5993 The anionic calixarenes para-sulphonatocalix[4]arene and 1,3-di-Ophosphonatocalix[ 4]arene, have been used to cap silver nanoparticles. The binding of these functional particles with regard to various serum albumins (bovine serum albumin, human serum albumin, porcine serum albumin and sheep serum albumin) has been studied by variable temperature fluorescence spectroscopy. The quenching of the fluorescence of the proteins was shown to vary as a function of the anionic calixarene capping molecule and also as a function of the origin of the serum albumin. It is thus possible to discriminate between the different species. Molecules 2013-05-21 18 5 Article 10.3390/molecules18055993 5993 6007 1420-3049 2013-05-21 doi: 10.3390/molecules18055993 Yannick Tauran Arnaud Brioude Beomjoon Kim Florent Perret Anthony Coleman http://www.mdpi.com/1420-3049/18/5/5980 Micheliolide (MCL) derivatives with etherification or esterification of the hydroxyl group at the C4 position were synthesized and evaluated for their activities against different acute myelogenous leukemia (AML) cell lines. These derivatives demonstrated comparable activities against AML cell lines HL-60 and doxorubicin resistant cell line HL-60/A. As to multi-drug resistant AML progenitor cells KG-1a, MCL and some of its derivatives maintained significant activities, and only 1.1–2.7 fold activity reductions were observed when compared with the activities against HL-60, while doxorubicin showed 20-fold activity reduction. Our study demonstrated that the C4 hydroxyl group of MCL might not only be a suitable position for structural modifications, but also be a starting point for the design of appropriate molecular probes to explore the specific targets in the progenitor cell line KG-1a. Molecules 2013-05-21 18 5 Article 10.3390/molecules18055980 5980 5992 1420-3049 2013-05-21 doi: 10.3390/molecules18055980 Wei-Wei Ma Qian-Qian Shi Ya-Hui Ding Jing Long Quan Zhang Yue Chen http://www.mdpi.com/1420-3049/18/5/5965 The effect of foliar salicylic acid (SA) applications (10−3 and 10−5 M) on activities of nitrate reductase, guaiacol peroxidase (POD), superoxide dismutases (SOD), catalase (CAT) and proline enzymes and physiological parameters was evaluated in two ginger varieties (Halia Bentong and Halia Bara) under greenhouse conditions. In both varieties, tested treatments generally enhanced photosynthetic rate and total dry weight. Photosynthetic rate increases were generally accompanied by increased or unchanged stomatal conductance levels, although intercellular CO2 concentrations of treated plants were typically lower than in controls. Lower SA concentrations were generally more effective in enhancing photosynthetic rate and plant growth. Exogenous application of SA increased antioxidant enzyme activities and proline content; the greatest responses were obtained in plants sprayed with 10–5 M SA, with significant increases observed in CAT (20.1%), POD (45.2%), SOD (44.1%) and proline (43.1%) activities. Increased CAT activity in leaves is naturally expected to increase photosynthetic efficiency and thus net photosynthesis by maintaining a constant CO2 supply. Our results support the idea that low SA concentrations (10–5 M) may induce nitrite reductase synthesis by mobilizing intracellular NO3− and can provide protection to nitrite reductase degradation in vivo in the absence of NO3–. Observed positive correlations among proline, SOD, CAT and POD activities in the studied varieties suggest that increased SOD activity was accompanied by increases in CAT and POD activities because of the high demands of H2O2 quenching. Molecules 2013-05-21 18 5 Article 10.3390/molecules18055965 5965 5979 1420-3049 2013-05-21 doi: 10.3390/molecules18055965 Ali Ghasemzadeh Hawa Jaafar http://www.mdpi.com/1420-3049/18/5/5954 The synthesis of nanoparticles has become a matter of great interest in recent times due to their various advantageous properties and applications in a variety of fields. The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (BS, Sargassum muticum) water extract containing sulphated polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. The structural and properties of the Fe3O4-NPs were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), vibrating sample magnetometry (VSM) and transmission electron microscopy. The average particle diameter as determined by TEM was found to be 18 ± 4 nm. X-ray diffraction showed that the nanoparticles are crystalline in nature, with a cubic shape. The nanoparticles synthesized through this biosynthesis method can potentially useful in various applications. Molecules 2013-05-21 18 5 Article 10.3390/molecules18055954 5954 5964 1420-3049 2013-05-21 doi: 10.3390/molecules18055954 Mahnaz Mahdavi Farideh Namvar Mansor Ahmad Rosfarizan Mohamad http://www.mdpi.com/1420-3049/18/5/5936 Several diterpenes with the labdane skeleton show biological activity, including antiproliferative effects. Most of the research work on bioactive labdanes has been carried out on naturally occurring diterpenes and semisynthetic derivatives, but much less is known on the effects of diterpene dimers. The aim of the present work was to synthesize dimeric diterpenes from the labdane imbricatolic acid using esters, ethers and the triazole ring as linkers. Some 18 new derivatives were prepared and the compounds were evaluated for antiproliferative activity on human normal fibroblasts (MRC-5) and the following human tumor cell lines: AGS, SK-MES-1, J82 and HL-60. The diethers 8–10, differing in the number of CH2 units in the linker, presented better antiproliferative activity with a maximum effect for the derivative 9. The best antiproliferative effect against HL-60 cells was found for compounds 3 and 17, with IC50 values of 22.3 and 23.2 μM, lower than that found for the reference compound etoposide (2.23 μM). The compounds 9, 17 and 11 were the most active derivatives towards AGS cells with IC50 values of 17.8, 23.4 and 26.1 μM. A free carboxylic acid function seems relevant for the effect as several of the compounds showed less antiproliferative effect after methylation. Molecules 2013-05-21 18 5 Article 10.3390/molecules18055936 5936 5953 1420-3049 2013-05-21 doi: 10.3390/molecules18055936 Mariano Pertino Cristina Theoduloz Marco Bastías Guillermo Schmeda-Hirschmann http://www.mdpi.com/1420-3049/18/5/5891 Alternaria is a cosmopolitan fungal genus widely distributing in soil and organic matter. It includes saprophytic, endophytic and pathogenic species. At least 268 metabolites from Alternaria fungi have been reported in the past few decades. They mainly include nitrogen-containing metabolites, steroids, terpenoids, pyranones, quinones, and phenolics. This review aims to briefly summarize the structurally different metabolites produced by Alternaria fungi, as well as their occurrences, biological activities and functions. Some considerations related to synthesis, biosynthesis, production and applications of the metabolites from Alternaria fungi are also discussed. Molecules 2013-05-21 18 5 Review 10.3390/molecules18055891 5891 5935 1420-3049 2013-05-21 doi: 10.3390/molecules18055891 Jingfeng Lou Linyun Fu Youliang Peng Ligang Zhou http://www.mdpi.com/1420-3049/18/5/5858 Recently, there has been significant progress in the field of soft- and hard-X-ray imaging for a wide range of applications, both technically and scientifically, via developments in sources, optics and imaging methodologies. While one community is pursuing extensive applications of available X-ray tools, others are investigating improvements in techniques, including new optics, higher spatial resolutions and brighter compact sources. For increased image quality and more exquisite investigation on characteristic biological phenomena, contrast agents have been employed extensively in imaging technologies. Heavy metal nanoparticles are excellent absorbers of X-rays and can offer excellent improvements in medical diagnosis and X-ray imaging. In this context, the role of gold (Au) is important for advanced X-ray imaging applications. Au has a long-history in a wide range of medical applications and exhibits characteristic interactions with X-rays. Therefore, Au can offer a particular advantage as a tracer and a contrast enhancer in X-ray imaging technologies by sensing the variation in X-ray attenuation in a given sample volume. This review summarizes basic understanding on X-ray imaging from device set-up to technologies. Then this review covers recent studies in the development of X-ray imaging techniques utilizing gold nanoparticles (AuNPs) and their relevant applications, including two- and three-dimensional biological imaging, dynamical processes in a living system, single cell-based imaging and quantitative analysis of circulatory systems and so on. In addition to conventional medical applications, various novel research areas have been developed and are expected to be further developed through AuNP-based X-ray imaging technologies. Molecules 2013-05-17 18 5 Review 10.3390/molecules18055858 5858 5890 1420-3049 2013-05-17 doi: 10.3390/molecules18055858 Sungsook Ahn Sung Jung Sang Lee http://www.mdpi.com/1420-3049/18/5/5814 The present paper reviews vasodilator compounds isolated from plants that were reported in the past 22 years (1990 to 2012) and the different mechanisms of action involved in their vasodilator effects. The search for reports was conducted in a comprehensive manner, intending to encompass those metabolites with a vasodilator effect whose mechanism of action involved both vascular endothelium and arterial smooth muscle. The results obtained from our bibliographic search showed that over half of the isolated compounds have a mechanism of action involving the endothelium. Most of these bioactive metabolites cause vasodilation either by activating the nitric oxide/cGMP pathway or by blocking voltage-dependent calcium channels. Moreover, it was found that many compounds induced vasodilation by more than one mechanism. This review confirms that secondary metabolites, which include a significant group of compounds with extensive chemical diversity, are a valuable source of new pharmaceuticals useful for the treatment and prevention of cardiovascular diseases. Molecules 2013-05-17 18 5 Review 10.3390/molecules18055814 5814 5857 1420-3049 2013-05-17 doi: 10.3390/molecules18055814 Francisco Luna-Vázquez César Ibarra-Alvarado Alejandra Rojas-Molina Isela Rojas-Molina Miguel Zavala-Sánchez http://www.mdpi.com/1420-3049/18/5/5804 Dried root of Rehmannia glutinosa is a kidney-tonifying herbal medicine with a long history of safe use in traditional folk medicine for the treatment of joint diseases. This study was conducted to investigate prevention of bone loss by a standardized dried root of R. glutinosa in an ovariectomized (OVX) rat model of osteoporosis. The OVX groups were divided into five groups treated with distilled water, 17β-estradiol (E2 10 µg/kg, once daily, i.p) and dried root of R. glutinosa extracts (DRGE 30, 100, and 300 mg/kg, twice daily, p.o) for eight weeks. We measured the body, organs, and uterus weights, and femur and lumbar vertebrae bone mineral density (BMD), serum alkaline phosphatase (ALP), estradiol levels. The treatments with DRGE 300 mg/kg significantly inhibited BMD decrease in the femur and lumbar (17.5% and 16.4%, p < 0.05, respectively) by OVX without affecting the body, organs, and uterus weights. Also, serum ALP level in the DRGE 300 mg/kg treated group was significantly decreased, but the estradiol level did not change in serum of the DRGE 300 mg/kg treated group. These results show that DRGE is able to prevent OVX-induced bone loss without influencing hormones such as estrogen. Molecules 2013-05-17 18 5 Communication 10.3390/molecules18055804 5804 5813 1420-3049 2013-05-17 doi: 10.3390/molecules18055804 Dong Lim Yun Kim http://www.mdpi.com/1420-3049/18/5/5792 Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean) and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea) and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa) were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop. Molecules 2013-05-17 18 5 Article 10.3390/molecules18055792 5792 5803 1420-3049 2013-05-17 doi: 10.3390/molecules18055792 Mayron de Vasconcelos Cláudio Cunha Francisco Arruda Victor Carneiro Rafaela Bastos Fábio Mercante Kyria Nascimento Benildo Cavada Ricardo Santos Edson Teixeira http://www.mdpi.com/1420-3049/18/5/5779 Dendrobium spp. are precious medicinal plants, used in China for thousands of years as health foods and nutrients. Polysaccharides are the main effective ingredients in Dendrobium plants. In this study, the chemical characteristics and the effects of crude polysaccharides (CPs) from five species of Dendrobium on macrophage function were investigated and compared in vitro for the first time. Chemical characteristic studies showed that CPs from different species of Dendrobium were diverse, displaying widely varied Mw distributions and molar ratios of monosaccharides. Their effects on macrophage functions, such as promoting phagocytosis, release of NO and cytokines IL-1α, IL-6, IL-10 and TNF-α, were also different. Moreover, CPs from D. officinale, especially collected from Yunnan Province, exerted the strongest immunomodulatory activities and could be explored as a novel potential functional food. The diverse chemical characteristics of CPs from different species of Dendrobium might contribute to their varied effects on macrophage functions, which should be further investigated. Molecules 2013-05-17 18 5 Article 10.3390/molecules18055779 5779 5791 1420-3049 2013-05-17 doi: 10.3390/molecules18055779 Lan-Zhen Meng Guang-Ping Lv De-Jun Hu Kit-Leong Cheong Jing Xie Jing Zhao Shao-Ping Li http://www.mdpi.com/1420-3049/18/5/5761 This manuscript describes the evaluation of anti-infective potential in vitro of organic extracts from nine sponges, one ascidian, two octocorals, one bryozoan, and 27 seaweed species collected along the Brazilian coast. Antimicrobial activity was tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 10231) by the disk diffusion method. Antiprotozoal activity was evaluated against Leishmania braziliensis (MHOM/BR/96/LSC96-H3) promastigotes and Trypanosoma cruzi (MHOM/BR/00/Y) epimastigotes by MTT assay. Activity against intracellular amastigotes of T. cruzi and L. brasiliensis in murine macrophages was also evaluated. Antiviral activity was tested against Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the plaque number reduction assay (IC50). Cytotoxicity on VERO cells was evaluated by the MTT assay (CC50). The results were expressed as SI = CC50/IC50. The most promising antimicrobial results were obtained against S. aureus and C. albicans with Dragmacidon reticulatum. Among the seaweeds, only Osmundaria obtusiloba showed moderate activity against P. aeruginosa. Concerning antiprotozoal activity, Bugula neritina, Carijoa riseii, Dragmaxia anomala and Haliclona (Halichoclona) sp. showed the most interesting results, mainly against extracellular promastigote forms of L. braziliensis (66, 35.9, 97.2, and 43.6% inhibition, respectively). Moreover, six species of seaweeds Anadyomene saldanhae, Caulerpa cupressoides, Canistrocarpus cervicornis, Dictyota sp., Ochtodes secundiramea, and Padina sp. showed promising results against L. braziliensis (87.9, 51.7, 85.9, 93.3, 99.7, and 80.9% inhibition, respectively), and only Dictyota sp. was effective against T. cruzi (60.4% inhibition). Finally, the antiherpes activity was also evaluated, with Haliclona (Halichoclona) sp. and Petromica citrina showing the best results (SI = 11.9 and SI > 5, respectively). All the active extracts deserve special attention in further studies to chemically characterize the bioactive compounds, and to perform more refined biological assays. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055761 5761 5778 1420-3049 2013-05-16 doi: 10.3390/molecules18055761 Éverson Bianco Simone de Oliveira Caroline Rigotto Maiko Tonini Tatiana da Rosa Guimarães Francine Bittencourt Lidiane Gouvêa Cassandra Aresi Maria de Almeida Maria Moritz Cintia Martins Fernando Scherner João Carraro Paulo Horta Flávio Reginatto Mario Steindel Cláudia Simões Eloir Schenkel http://www.mdpi.com/1420-3049/18/5/5749 Oil-chitosan composite spheres were synthesized by encapsulation of sunflower seed oil in chitosan droplets, dropping into NaOH solution and in situ solidification. Hydrophilic materials (i.e., iron oxide nanoparticles) and lipophilic materials (i.e., rhodamine B or epirubicin) could be encapsulated simultaneously in the spheres in a one step process. The diameters of the prepared spheres were 2.48 ± 0.11 mm (pure chitosan spheres), 2.31 ± 0.08 mm (oil-chitosan composites), 1.49 ± 0.15 mm (iron-oxide embedded oil-chitosan composites), and 1.69 ± 0.1 mm (epirubicin and iron oxide encapsulated oil-chitosan composites), respectively. Due to their superparamagnetic properties, the iron-oxide embedded oil-chitosan composites could be guided by a magnet. A lipophilic drug (epirubicin) could be loaded in the spheres with encapsulation rate measured to be 72.25%. The lipophilic fluorescent dye rhodamine B was also loadable in the spheres with red fluorescence being observed under a fluorescence microscope. We have developed a novel approach to an in situ process for fabricating oil-chitosan composite spheres with dual encapsulation properties, which are potential multifunctional drug carriers. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055749 5749 5760 1420-3049 2013-05-16 doi: 10.3390/molecules18055749 Keng-Shiang Huang Chih-Yu Wang Chih-Hui Yang Alexandru Grumezescu Yung-Sheng Lin Chao-Pin Kung I-Yin Lin Yi-Ching Chang Wei-Jie Weng Wei-Ting Wang http://www.mdpi.com/1420-3049/18/5/5736 As part of a program aiming at the selection of yeast strains which might be of interest as sources of natural flavours and fragrances, the bioreduction of (4R)-(−)-carvone and (1R)-(−)-myrtenal by whole-cells of non-conventional yeasts (NCYs) belonging to the genera Candida, Cryptococcus, Debaryomyces, Hanseniaspora, Kazachstania, Kluyveromyces, Lindnera, Nakaseomyces, Vanderwaltozyma and Wickerhamomyces was studied. Volatiles produced were sampled by means of headspace solid-phase microextraction (SPME) and the compounds were analysed and identified by gas chromatography–mass spectroscopy (GC-MS). Yields (expressed as % of biotransformation) varied in dependence of the strain. The reduction of both (4R)-(−)-carvone and (1R)-(−)-myrtenal were catalyzed by some ene-reductases (ERs) and/or carbonyl reductases (CRs), which determined the formation of (1R,4R)-dihydrocarvone and (1R)-myrtenol respectively, as main flavouring products. The potential of NCYs as novel whole-cell biocatalysts for selective biotransformation of electron-poor alkenes for producing flavours and fragrances of industrial interest is discussed. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055736 5736 5748 1420-3049 2013-05-16 doi: 10.3390/molecules18055736 Marta Goretti Benedetta Turchetti Maria Cramarossa Luca Forti Pietro Buzzini http://www.mdpi.com/1420-3049/18/5/5723 Four new citrinin derivatives, including two citrinin dimers and two citrinin monomer derivatives, were isolated and identified from a marine-derived fungal strain Penicillium sp. ML226 along with six known related compounds. Their structures were elucidated by spectroscopic and chemical methods. The new compounds showed modest cytotoxic activity against HepG-2 cell line and weak antimicrobial activity against Staphylococcus aureus. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055723 5723 5735 1420-3049 2013-05-16 doi: 10.3390/molecules18055723 Mei Wang Chun Lu Qing Xu Si Song Zhi Hu Zhong Zheng http://www.mdpi.com/1420-3049/18/5/5706 Proteolytic cleavage of amyloid precursor protein by β-secretase (BACE1) is a key step in generating the N-terminal of β-amyloid (Aβ), which further forms into amyloid plaques that are considered as the hallmark of Alzheimer’s disease. Inhibitors of BACE1 can reduce the levels of Aβ and thus have a therapeutic potential for treating the disease. We report here the identification of a series of small molecules bearing an indole acylguanidine core structure as potent BACE1 inhibitors. The initial weak fragment was discovered by virtual screening, and followed with a hit-to-lead optimization. With the aid of co-crystal structures of two discovered inhibitors (compounds 19 and 25) with BACE1, we explored the SAR around the indole and aryl groups, and obtained several BACE1 inhibitors about 1,000-fold more potent than the initial fragment hit. Accompanying the lead optimization, a previously under-explored sub-site opposite the flap loop was redefined as a potential binding site for later BACE1 inhibitor design. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055706 5706 5722 1420-3049 2013-05-16 doi: 10.3390/molecules18055706 Yiquan Zou Li Li Wuyan Chen Tiantian Chen Lanping Ma Xin Wang Bing Xiong Yechun Xu Jingkang Shen http://www.mdpi.com/1420-3049/18/5/5697 The trace impurities discovered after extended storage of a 5-amino- benzimidazole library were determined as imidazo[4,5-g]quinazoline derivatives by extensive spectroscopic data analysis. The formation of this highly aromatic heterocyclic ring involved a novel multi-component reaction, using which several novel compounds were prepared. Its mechanism was deduced as a cascade of chemical transformations, including the formation of a Schiff’s base, intramolecular hetero-Diels-Alder reaction, defluorination and dehydrogenation. Molecules 2013-05-16 18 5 Article 10.3390/molecules18055697 5697 5705 1420-3049 2013-05-16 doi: 10.3390/molecules18055697 Li Li Qianqian Zhang Bo Liu Gang Liu http://www.mdpi.com/1420-3049/18/5/5684 The aim of this research was to determine the chemical composition of the essential oil of Acorus calamus rhizomes, its insecticidal activity against the booklouse, (Liposcelis bostrychophila) and to isolate any insecticidal constituents from the essential oil. The essential oil of A. calamus rhizomes was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. A total of 32 components of the essential oil of A. calamus rhizomes was identified and the principal compounds in the essential oil were determined to be α-asarone (50.09%), (E)-methylisoeugenol (14.01%), and methyleugenol (8.59%), followed by β-asarone (3.51%), α-cedrene (3.09%) and camphor (2.42%). Based on bioactivity-guided fractionation, the three active constituents were isolated from the essential oil and identified as methyleugenol, (E)-methylisoeugenol and α-asarone. The essential oil exhibited contact toxicity against L. bostrychophila with an LD50 value of 100.21 µg/cm2 while three constituent compounds, α-asarone, methyleugenol, and (E)-methylisoeugenol had LD50 values of 125.73 µg/cm2, 103.22 µg/cm2 and 55.32 µg/cm2, respectively. Methyleugenol and (E)-methylisoeugenol possessed fumigant toxicity against L. bostrychophila adults with LC50 values of 92.21 μg/L air and 143.43 μg/L air, respectively, while the crude essential oil showed an LC50 value of 392.13 μg/L air. The results indicate that the essential oil of A. calamus rhizomes and its constituent compounds have potential for development into natural fumigants/insecticides for control of the booklice. Molecules 2013-05-15 18 5 Article 10.3390/molecules18055684 5684 5696 1420-3049 2013-05-15 doi: 10.3390/molecules18055684 Xin Liu Li Zhou Zhi Liu Shu Du http://www.mdpi.com/1420-3049/18/5/5669 Eighteen (3R) and (3R,4R)-N-phenyl-, N-phenylalkyl and N-arylsuccinimides were prepared with high enantioselectivity by biotransformation of maleimides with A. fumigatus. This environmentally friendly, clean and economical procedure was performed by the whole-cell fungal bioconversion methodology. Their corresponding eighteen racemic succinimides were prepared instead by synthetic methods. Both, the racemic and the chiral succinimides were tested simultaneously by the microbroth dilution method of CLSI against a panel of human opportunistic pathogenic fungi of clinical importance. Chiral succinimides showed higher antifungal activity than the corresponding racemic ones and the differences in activity were established by statistical methods. The bottlenecks for developing chiral drugs are how to obtain them through a low-cost procedure and with high enantiomeric excess. Results presented here accomplish both these objectives, opening an avenue for the development of asymmetric succinimides as new antifungal drugs for pharmaceutical use. Molecules 2013-05-15 18 5 Article 10.3390/molecules18055669 5669 5683 1420-3049 2013-05-15 doi: 10.3390/molecules18055669 Maximiliano Sortino Agustina Postigo Susana Zacchino http://www.mdpi.com/1420-3049/18/5/5648 A water-soluble indocarbocyanine dye was synthesized and its photophysics were studied for the first time on two solid hosts, microcrystalline cellulose and b-cyclodextrin, as well as in homogeneous media. The inclusion of the indocarbocyanine moiety onto microcrystalline cellulose increased the dye aggregation with both H and J aggregates being formed. Adsorption on b-cyclodextrin enhanced aggregation in a similar way. The fluorescence quantum yields were determined for the powdered samples of the cyanine dye on the two hosts and a significant increase was observed relative to homogeneous solution. A remarkable concentration dependence was also detected in both cases. A lifetime distribution analysis has shown that the indocarbocyanine dye mainly occupies the amorphous part of cellulose and is not entrapped in the crystalline part of this host. In the b-CD case, the adsorption occurs outside the host cavity. In both hosts a strong concentration quenching effect is observed and only monomers emit. Both adsorptions may be explained by stereochemical constraints imposed by the two long sulphoethyl tails linked to nitrogen atoms of the indocarbocyanine dye. Molecules 2013-05-15 18 5 Article 10.3390/molecules18055648 5648 5668 1420-3049 2013-05-15 doi: 10.3390/molecules18055648 Reda El-Shishtawy Anabela Oliveira Paulo Almeida Diana Ferreira David Conceição Luis Ferreira http://www.mdpi.com/1420-3049/18/5/5611 Gene therapy involves the introduction of foreign genetic material into cells in order exert a therapeutic effect. The application of gene therapy to the field of orthopaedic tissue engineering is extremely promising as the controlled release of therapeutic proteins such as bone morphogenetic proteins have been shown to stimulate bone repair. However, there are a number of drawbacks associated with viral and synthetic non-viral gene delivery approaches. One natural polymer which has generated interest as a gene delivery vector is chitosan. Chitosan is biodegradable, biocompatible and non-toxic. Much of the appeal of chitosan is due to the presence of primary amine groups in its repeating units which become protonated in acidic conditions. This property makes it a promising candidate for non-viral gene delivery. Chitosan-based vectors have been shown to transfect a number of cell types including human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). Aside from its use in gene delivery, chitosan possesses a range of properties that show promise in tissue engineering applications; it is biodegradable, biocompatible, has anti-bacterial activity, and, its cationic nature allows for electrostatic interaction with glycosaminoglycans and other proteoglycans. It can be used to make nano- and microparticles, sponges, gels, membranes and porous scaffolds. Chitosan has also been shown to enhance mineral deposition during osteogenic differentiation of MSCs in vitro. The purpose of this review is to critically discuss the use of chitosan as a gene delivery vector with emphasis on its application in orthopedic tissue engineering. Molecules 2013-05-15 18 5 Review 10.3390/molecules18055611 5611 5647 1420-3049 2013-05-15 doi: 10.3390/molecules18055611 Rosanne Raftery Fergal O'Brien Sally-Ann Cryan http://www.mdpi.com/1420-3049/18/5/5594 Angiogenesis plays a key role in cancer progression and correlates with disease aggressiveness and poor clinical outcomes. Affinity ligands discovered by screening phage display random peptide libraries can be engineered to molecularly target tumor blood vessels for noninvasive imaging and early detection of tumor aggressiveness. In this study, we tested the ability of a phage-display-selected peptide sequence recognizing specifically bone marrow- derived pro-angiogenic tumor-homing cells, the QFP-peptide, radiolabeled with 64Cu radioisotope to selectively image tumor vasculature in vivo by positron emission tomography (PET). To prepare the targeted PET tracer we modified QFP-phage with the DOTA chelator and radiolabeled the purified QFP-phage-DOTA intermediate with 64Cu to obtain QFP-targeted radioconjugate with high radiopharmaceutical yield and specific activity. We evaluated the new PET tracer in vivo in a subcutaneous (s.c.) Lewis lung carcinoma (LLC) mouse model and conducted tissue distribution, small animal PET/CT imaging study, autoradiography, histology, fluorescence imaging, and dosimetry assessments. The results from this study show that, in the context of the s.c. LLC immunocompetent mouse model, the QFP-tracer can target tumor blood vessels selectively. However, further optimization of the biodistribution and dosimetry profile of the tracer is necessary to ensure efficient radiopharmaceutical applications enabled by the biological specificity of the QFP-peptide. Molecules 2013-05-15 18 5 Article 10.3390/molecules18055594 5594 5610 1420-3049 2013-05-15 doi: 10.3390/molecules18055594 Cam Patterson C. Frederick Hong Yuan Laura Dyer Pamela Lockyer David Lalush Anka Veleva http://www.mdpi.com/1420-3049/18/5/5580 A hexachlorocyclotriphosphazene (HCCP)-mediated direct formation of quinazoline (thio)ethers from quinazolin-4(3H)-ones has been developed. Treatment of quinazolin-4(3H)-ones with HCCP, diisopropylethylamine (DIPEA), and thiophenols resulted in formation of the corresponding 4-arylthioquinazoline derivatives in moderate to excellent yields. This method has also been utilized to prepare 4-aryloxyquinazoline and 4-alkoxyquinazoline derivatives using phenols and sodium alkoxides as the nucleophiles. Molecules 2013-05-15 18 5 Article 10.3390/molecules18055580 5580 5593 1420-3049 2013-05-15 doi: 10.3390/molecules18055580 Baoxiang Hu Xiaochu Zhang Lili Sheng Ming Guo Zhenlu Shen Xinquan Hu Nan Sun Weimin Mo http://www.mdpi.com/1420-3049/18/5/5568 Three new multiflorane-type triterpenes; 7a-methoxymultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (1), 7-oxomultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (2), and multiflora-7,9(11)-diene-3a,29-diol 3-p-hydroxybenzoate-29-benzoate (3), were isolated from seeds of Cucurbita maxima, along with three known compounds. Compound 3 and multiflora-7,9(11)-diene-3a-29-diol 3-benzoate (5) exhibited potent inhibitory effects on melanogenesis, with low cytotoxicities, and 2 exhibited single-digit micromolar cytotoxicity against HL-60 and P388 cells. Molecules 2013-05-14 18 5 Article 10.3390/molecules18055568 5568 5579 1420-3049 2013-05-14 doi: 10.3390/molecules18055568 Takashi Kikuchi Mika Takebayashi Mayumi Shinto Takeshi Yamada Reiko Tanaka http://www.mdpi.com/1420-3049/18/5/5543 Kinetic Isotope effects (KIEs) have long served as a probe for the mechanisms of both enzymatic and solution reactions. Here, we discuss various models for the physical sources of KIEs, how experimentalists can use those models to interpret their data, and how the focus of traditional models has grown to a model that includes motion of the enzyme and quantum mechanical nuclear tunneling. We then present two case studies of enzymes, thymidylate synthase and alcohol dehydrogenase, and discuss how KIEs have shed light on the C-H bond cleavages those enzymes catalyze. We will show how the combination of both experimental and computational studies has changed our notion of how these enzymes exert their catalytic powers. Molecules 2013-05-14 18 5 Review 10.3390/molecules18055543 5543 5567 1420-3049 2013-05-14 doi: 10.3390/molecules18055543 Daniel Roston Zahidul Islam Amnon Kohen http://www.mdpi.com/1420-3049/18/5/5531 Water extractable arabinoxylan (WEAX) aerogels were prepared by extracting the solvent from the alcogels (WEAX hydrogels with an alcohol as the solvent) with carbon dioxide under supercritical conditions. WEAX aerogels were characterized using scanning electron microscopy and adsorption and desorption nitrogen isotherms. The micrographs indicate a heterogeneous porous network structure in WEAX aerogel. Adsorption/desorption nitrogen isotherms of this material were type IV, which confirm that this material possess a mesoporous structure. WEAX aerogels rehydration capability was evaluated and the water absorption mechanism was determined. The WEAX aerogels water absorption mechanism was non-Fickian (n = 0.54). Molecules 2013-05-14 18 5 Article 10.3390/molecules18055531 5531 5542 1420-3049 2013-05-14 doi: 10.3390/molecules18055531 Jorge Marquez-Escalante Elizabeth Carvajal-Millan Mario Miki-Yoshida Lorena Alvarez-Contreras Alma Toledo-Guillén Jaime Lizardi-Mendoza Agustín Rascón-Chu http://www.mdpi.com/1420-3049/18/5/5517 The synthesis of a newangular analog 11 of cyclozonarone was achieved via Diels-Alder reaction between a sesquiterpene-1,3-diene and 1,4-benzoquinone. The cytotoxic activity of ent-cyclozonarone [(+)-10] and the angular (−)-cyclozonarone analog 11 has been determined in three human cancer cell lines and in normal fibroblasts using the sulforhodamine B assay. The analyzed isomers induce cell death in different cancer cell lines by eliciting nuclear condensation and fragmentation, decreasing mitochondrial membrane permeability and increasing caspase-3 activity, all traits indicating apoptosis, with the effects of (+)-10 being stronger than those of 11 in all cases. Molecules 2013-05-13 18 5 Article 10.3390/molecules18055517 5517 5530 1420-3049 2013-05-13 doi: 10.3390/molecules18055517 Natalia Sobarzo Iván Venegas Cristian Sánchez Luis Catalán Cristóbal Rojas Valentina Valdivia Joan García Mauricio Fritis http://www.mdpi.com/1420-3049/18/5/5498 A series of novel 3-benzisoxazolyl-4-indolyl-maleimides were synthesized and evaluated for their GSK-3β inhibitory activity. Most compounds exhibited high inhibitory potency towards GSK-3β. Among them, compound 7j with an IC50 value of 0.73 nM was the most promising GSK-3β inhibitor. Preliminary structure-activity relationships were examined and showed that different substituents on the indole ring and N1-position of the indole ring had varying degrees of influence on the GSK-3β inhibitory potency. Compounds 7c, 7f, 7j–l and 7o–q could obviously reduce Aβ-induced Tau hyperphosphorylation by inhibiting GSK-3β in a cell-based functional assay. Molecules 2013-05-13 18 5 Article 10.3390/molecules18055498 5498 5516 1420-3049 2013-05-13 doi: 10.3390/molecules18055498 Qing Ye Meng Li Yubo Zhou Tao Pang Lei Xu Jiayi Cao Liang Han Yujin Li Weisi Wang Jianrong Gao Jia Li http://www.mdpi.com/1420-3049/18/5/5482 New hetaryl- and alkylidenerhodanine derivatives 3a–d, 3e, and 4a–d were prepared from heterocyclic aldehydes 1a–d or acetaldehyde 1e. The treatment of several rhodanine derivatives 3a–d and 3e with piperidine or morpholine in THF under reflux, afforded (Z)-5-(hetarylmethylidene)-2-(piperidin-1-yl)thiazol-4(5H)-ones and 2-morpholinothiazol-4(5H)-ones 5a–d, 6a–d, and (Z)-5-ethylidene-2-morpholinothiazol-4(5H)-one (5e), respectively, in good yields. Structures of all compounds were determined by IR, 1D and 2D NMR and mass spectrometry. Several of these compounds were screened by the U.S. National Cancer Institute (NCI) to assess their antitumor activity against 60 different human tumor cell lines. Compound 3c showed high activity against HOP-92 (Non-Small Cell Lung Cancer), which was the most sensitive cell line, with GI50 = 0.62 μM and LC50 > 100 μM from the in vitro assays. In vitro antifungal activity of these compounds was also determined against 10 fungal strains. Compound 3e showed activity against all fungal strains tested, but showed high activity against Saccharomyces cerevisiae (MIC 3.9 μg/mL). Molecules 2013-05-13 18 5 Article 10.3390/molecules18055482 5482 5497 1420-3049 2013-05-13 doi: 10.3390/molecules18055482 Alberto Insuasty Juan Ramírez Marcela Raimondi Carlos Echeverry Jairo Quiroga Rodrigo Abonia Manuel Nogueras Justo Cobo María Rodríguez Susana Zacchino Braulio Insuasty http://www.mdpi.com/1420-3049/18/5/5472 Enantioselective esterification of ibuprofen has been successfully carried out in an organic solvent catalyzed by recombinant APE 1547 (a thermophilic esterase from the archaeon Aeropyrum pernix K1). Here we used microwave irradiation (MW) as the mode of heating to improve the enzyme performance. Under the optimum conditions, the enzyme activity of APE 1547 was 4.16 μmol/mg/h and the enantioselectivity (E value) was 52.9. Compared with conventional heating, the enzyme activity and the enantioselectivity were increased about 21.9-fold and 1.4-fold, respectively. The results also indicated that APE 1547 can maintain 95% of its activity even after being used five times, suggesting that the enzyme is stable under low power MW conditions. Molecules 2013-05-13 18 5 Article 10.3390/molecules18055472 5472 5481 1420-3049 2013-05-13 doi: 10.3390/molecules18055472 Zecheng Yang Xuedun Niu Xuedong Fang Ge Chen Hong Zhang Hong Yue Lei Wang Dantong Zhao Zhi Wang http://www.mdpi.com/1420-3049/18/5/5455 The aim of this study was to develop novel transdermal films of ondansetron HCl with high molecular weight chitosan as matrix polymer and 2-(2-ethoxy-ethoxy) ethanol (Transcutol®) as plasticizer. In this context, firstly the physicochemical properties of gels used to formulate transdermal films were characterized and, physicochemical properties and bioadhesiveness of the transdermal films prepared with chitosan gels were assessed. The impact of three different types of terpenes, namely limonene, nerolidol and eucalyptol on in vitro skin permeation of ondansetron from transdermal films were also examined. ATR-FTIR measurements were performed to investigate the effects of the chitosan film formulations on in vitro conformational order of stratum corneum intercellular lipids after 24 h permeation study. The results showed that the chitosan gels consisting of Transcutol® as plasticizer and terpenes as penetration enhancer may be used to prepare transdermal films of ondansetron due to the good mechanical properties and bioadhesiveness of the transdermal films. Eucalyptol (1%) showed higher permeation enhancer effect than the other terpenes and control. ATR-FTIR data confirmed that finding in which eucalyptol induced a blue shift in the both CH2 asymmetric and symmetric absorbance peak positions indicating increased lipid fluidity of stratum corneum. Molecules 2013-05-10 18 5 Article 10.3390/molecules18055455 5455 5471 1420-3049 2013-05-10 doi: 10.3390/molecules18055455 Aslı Can Meryem Erdal Sevgi Güngör Yıldız Özsoy http://www.mdpi.com/1420-3049/18/5/5434 The fragrant camphor tree (Cinnamomum camphora) and its products, such as camphor oil, have been coveted since ancient times. Having a rich history of traditional use, it was particularly used as a fumigant during the era of the Black Death and considered as a valuable ingredient in both perfume and embalming fluid. Camphor has been widely used as a fragrance in cosmetics, as a food flavourant, as a common ingredient in household cleaners, as well as in topically applied analgesics and rubefacients for the treatment of minor muscle aches and pains. Camphor, traditionally obtained through the distillation of the wood of the camphor tree, is a major essential oil component of many aromatic plant species, as it is biosynthetically synthesised; it can also be chemically synthesised using mainly turpentine as a starting material. Camphor exhibits a number of biological properties such as insecticidal, antimicrobial, antiviral, anticoccidial, anti-nociceptive, anticancer and antitussive activities, in addition to its use as a skin penetration enhancer. However, camphor is a very toxic substance and numerous cases of camphor poisoning have been documented. This review briefly summarises the uses and synthesis of camphor and discusses the biological properties and toxicity of this valuable molecule. Molecules 2013-05-10 18 5 Review 10.3390/molecules18055434 5434 5454 1420-3049 2013-05-10 doi: 10.3390/molecules18055434 Weiyang Chen Ilze Vermaak Alvaro Viljoen http://www.mdpi.com/1420-3049/18/5/5420 A series of new matrinic acid derivatives 5a–e was synthesized. The chemical structures of the synthesized compounds were confirmed by 1H-NMR, 13C-NMR, and electrospray ionization mass spectroscopy. The anti-tumor activities were also investigated in vitro by evaluating the effect of synthesized compounds on the proliferation of A375, A549, HeLa, and HepG2 cells. Compound 5e was found to be the most potent against A375 and HeLa cells, with IC50 values of 37 and 75.5 μg/mL, respectively. Compounds 5b, 5c, 5g, and 5h also exhibited antiproliferative activities against A549 cells, with IC50 values within the 36.2–47 μg/mL range. For HepG2 cells, 5e and 5i, with IC50 values of 78.9 and 61 μg/mL, respectively, showed higher antiproliferative activity than taxol. Molecules 2013-05-10 18 5 Article 10.3390/molecules18055420 5420 5433 1420-3049 2013-05-10 doi: 10.3390/molecules18055420 Fan Chao Dong-En Wang Rui Liu Qin Tu Jian-Jun Liu Jinyi Wang http://www.mdpi.com/1420-3049/18/5/5405 Ultraviolet (UV) radiation induces DNA damage, oxidative stress, and inflammatory processes in human epidermis, resulting in inflammation, photoaging, and photocarcinogenesis. Adequate protection of skin against the harmful effect of UV irradiation is essential. In recent years naturally occurring herbal compounds such as phenolic acids, flavonoids, and high molecular weight polyphenols have gained considerable attention as beneficial protective agents. The simple phenolic veratric acid (VA, 3,4-dimethoxybenzoic acid) is one of the major benzoic acid derivatives from vegetables and fruits and it also occurs naturally in medicinal mushrooms which have been reported to have anti-inflammatory and anti-oxidant activities. However, it has rarely been applied in skin care. This study, therefore, aimed to explore the possible roles of veratric acid in protection against UVB-induced damage in HaCaT cells. Results showed that veratric acid can attenuate cyclobutane pyrimidine dimers (CPDs) formation, glutathione (GSH) depletion and apoptosis induced by UVB. Furthermore, veratric acid had inhibitory effects on the UVB-induced release of the inflammatory mediators such as IL-6 and prostaglandin-E2. We also confirmed the safety and clinical efficacy of veratric acid on human skin. Overall, results demonstrated significant benefits of veratric acid on the protection of keratinocyte against UVB-induced injuries and suggested its potential use in skin photoprotection. Molecules 2013-05-10 18 5 Article 10.3390/molecules18055405 5405 5419 1420-3049 2013-05-10 doi: 10.3390/molecules18055405 Seoung Shin Eunsun Jung Seungbeom Kim Kyung-Eun Lee Jong-Kyung Youm Deokhoon Park http://www.mdpi.com/1420-3049/18/5/5389 Curcumin is the major phenolic compound present in turmeric (Curcuma longa L.). Curcumin and 15 novel analogs were investigated for their antioxidant and selected biological activities. Strong relationships between the structure and evaluated activity revealed that the compounds with specific functional groups and carbon skeleton had specific biological profiles. Among the compounds tested, the derivatives (E)-2-(3,4-dimethoxybenzylidene)-5-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclopentanone (3e), and (E)-2-(4-hydroxy-3-methoxybenzylidene)-5-((E)-3-(4-hydroxy-3-methoxyphenyl)acryloyl)-cyclopentanone (3d) and the parent compound curcumin exhibited the strongest free radical scavenging and antioxidant capacity. Concerning the other biological activities studied the compound (E)-2-(4-hydroxy-3-methoxybenzylidene)-5-((E)-3-(4-hydroxy-3-methoxy-phenyl)-acryloyl)cyclopentanone (3d) was the most potent angiotensin converting enzyme (ACE) inhibitor, while the derivatives (E)-2-(4-hydroxybenzylidene)-6-((E)-3-(4-hydroxyphenyl)acryloyl)cyclohexanone (2b), (E)-2-(3,4-dimethoxybenzylidene)-6-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclohexanone (2e) and (E)-2-(3,4-dimethoxybenzylidene)-5-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclopentanone (3e) exhibited strong tyrosinase inhibition. Moreover, (E)-2-(3,4-dimethoxybenzylidene)-6-((E)-3-(3,4-dimethoxyphenyl)-acryloyl)cyclohexanone (2e) was also found to be the strongest human HIV-1 protease inhibitor in vitro among the tested compounds. Cytotoxicity studies using normal human lung cells revealed that the novel curcumin as well as its carbocyclic analogs are not toxic. Molecules 2013-05-10 18 5 Article 10.3390/molecules18055389 5389 5404 1420-3049 2013-05-10 doi: 10.3390/molecules18055389 Khushwant Bhullar Amitabh Jha Dani Youssef H. Rupasinghe