Display options:
Normal
Show Abstracts
Compact
Select/unselect all
Displaying article 1-33
p. 3844-3850
Received: 28 August 2009; in revised form: 21 September 2009 / Accepted: 25 September 2009 / Published: 28 September 2009
Show/Hide Abstract
| Download PDF Full-text (104 KB) Abstract: One new drimane-type sesquiterpenoid, named ugandenial A (1), was isolated from the ethyl acetate extract of the bark of Warburgia ugandensis (Canellaceae) together with eight known drimane-type sesquiterpenoids: 11α-hydroxycinnamosmolide (2), warburganal (3), polygodial (4), mukaadial (5), dendocarbin A (6), 9α-hydroxycinnamolide (7), dendocarbin L (8) and dendocarbin M (9). Their structures were established by detailed spectroscopic analysis. In addition a keto-enol equilibrium was demonstrated for compound 1 through a detailed NMR analysis run in CD2 Cl2 at 190 K. Cytotoxicity of the isolated compounds against KB cells was evaluated.
p. 3851-3867
Received: 10 August 2009; in revised form: 14 September 2009 / Accepted: 22 September 2009 / Published: 28 September 2009
Show/Hide Abstract
| Download PDF Full-text (1062 KB) Abstract: A family of dendritic tris-bipyridyl ruthenium coordination complexes incorporating two or four carboxylate groups for binding to a TiO2 surface site and another dendritic linker between the metal complex and highly absorptive dyes were formulated as thin films on TiO2 coated glass. The family included phenothiazine-substituted dendrons of increasing structural complexity and higher optical density. The dye-loaded films were characterized by steady-state emission and absorption measurements and by kinetic studies of luminescence and transient absorption. Upon photoexcitation of the bound dyes, rapid electron injection into the metal oxide film was the dominant observed process, producing oxidized dye that persisted for hundreds of milliseconds. Complex decay profiles for emission, transient absorption, and optical bleaching of the dendritic dyes point to highly heterogeneous behavior for the films, with observed persistence lifetimes related directly to structurally enhance electronic coupling between the metal oxide support and the dendritic dyes.
p. 3868
Received: 9 September 2009 / Published: 28 September 2009
Show/Hide Abstract
| Download PDF Full-text (16 KB) Abstract: We realized that the affiliations of the authors were incorrectly listed in our paper published in Molecules recently [1]. [...]
p. 3869-3880
Received: 10 September 2009; in revised form: 28 September 2009 / Accepted: 28 September 2009 / Published: 29 September 2009
Show/Hide Abstract
| Download PDF Full-text (89 KB) Abstract: Alfacalcidol (1α-hydroxyvitamin D3 ) has been widely used since 1981 as a prodrug for calcitriol (1α,25-dihydroxyvitamin D3 ) in the treatment of hypocalcemia, chronic renal failure, hypoparathyroidism and osteoporosis. More recently, doxercalciferol (1α-hydroxyvitamin D2 ) has been used since 1999 as a prodrug for 1α,25-dihydroxyvitamin D2 for the treatment of secondary hyperparathyroidism. Currently, six forms of vitamin D are known. They range from vitamin D2 to vitamin D7 and are distinguished by their differing side chains. Only vitamin D2 and vitamin D3 have been found to be biologically active based on the elucidation of activation pathways. Alfacalcidol and osteoporosis/doxercalciferol and secondary hyperparathyroidism are discussed, with a new look at old compounds including their practical syntheses.
(This article belongs to the Special Issue
Prodrugs )
p. 3881-3905
Received: 31 August 2009; in revised form: 22 September 2009 / Accepted: 27 September 2009 / Published: 29 September 2009
Show/Hide Abstract
| Download PDF Full-text (272 KB) Abstract: Novel polyfunctional small amphiphilic peptide dendrimers characterized by incorporation of a new core compounds – tris -amino acids or tetrakis -amino alcohols that originated from a series of basic amino acids – were efficiently synthesized. These new core elements yielded molecules with multiple branching and (+5)/(+6) charge at the 1-st dendrimer generation. Dendrimers exhibited significant antimicrobial potency against Gram(+) and Gram(-) strains involving also multiresistant reference strains (S. aureus ATCC 43300 and E. coli ATCC BAA-198). In addition, high activity against fungi from the Candida genus was detected. More charged and more hydrophobic peptide dendrimers expressed hemolytic properties.
p. 3906-3913
Received: 13 August 2009; in revised form: 5 September 2009 / Accepted: 15 September 2009 / Published: 30 September 2009
Show/Hide Abstract
| Download PDF Full-text (151 KB) Abstract: This study assessed the inhibitory effect of three C-glycosylflavonoids from Cymbopogon citratus leaves - isoorientin (1), swertiajaponin (2) and isoorientin 2"-Orhamnoside (3) - on human LDL oxidation. Isolated LDL was incubated with compounds 1-3 and the kinetics of lipid peroxidation were assessed by conjugated diene and malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) formation after addition of copper ions. Significant differences (p < 0.05) between the lag time phase of the control and the lag time phase in the presence of the compounds 1 (0.25 µM) and 2 (0.50 µM) were observed. After five hours of incubation all three compounds showed a significant inhibitory effect on MDA-TBARS formation with respect to the control. After six hours of incubation only compound 1 kept a remarkable antioxidant effect. This study demonstrates that isoorientin (1) is an effective inhibitor of in vitro LDL oxidation. As oxidative damage to LDL is a key event in the formation of atherosclerotic lesions, the use of this natural antioxidant may be beneficial to prevent or attenuate atherosclerosis.
p. 3914-3921
Received: 8 September 2009; in revised form: 29 September 2009 / Accepted: 30 September 2009 / Published: 30 September 2009
Show/Hide Abstract
| Download PDF Full-text (204 KB) Abstract: An efficient three-step solid-phase synthesis of diverse 3,5-disubstituted-2-aminofuranones has been developed. α-Hydroxy acids loaded on a nitrophenyl carbonate derivative of Wang resin are used as acylating agents for the C -acylation of active methylene compounds and the resulting intermediates provided, through a cyclative cleavage reaction, the desired product.
p. 3922-3941
Received: 30 June 2009; in revised form: 15 September 2009 / Accepted: 17 September 2009 / Published: 9 October 2009
Show/Hide Abstract
| Download PDF Full-text (220 KB) Abstract: Centella asiatica accumulates large quantities of pentacyclic triterpenoid saponins, collectively known as centelloids. These terpenoids include asiaticoside, centelloside, madecassoside, brahmoside, brahminoside, thankuniside, sceffoleoside, centellose, asiatic-, brahmic-, centellic- and madecassic acids. The triterpene saponins are common secondary plant metabolites and are synthesized via the isoprenoid pathway to produce a hydrophobic triterpenoid structure (aglycone) containing a hydrophilic sugar chain (glycone). The biological activity of saponins has been attributed to these characteristics. In planta , the Centella triterpenoids can be regarded as phytoanticipins due to their antimicrobial activities and protective role against attempted pathogen infections. Preparations of C. asiatica are used in traditional and alternative medicine due to the wide spectrum of pharmacological activities associated with these secondary metabolites. Here, the biosynthesis of the centelloid triterpenoids is reviewed; the range of metabolites found in C. asiatica , together with their known biological activities and the chemotype variation in the production of these metabolites due to growth conditions are summarized. These plant-derived pharmacologically active compounds have complex structures, making chemical synthesis an economically uncompetitive option. Production of secondary metabolites by cultured cells provides a particularly important benefit to manipulate and improve the production of desired compounds; thus biotechnological approaches to increase the concentrations of the metabolites are discussed.
p. 3942-3951
Received: 14 August 2009; in revised form: 9 September 2009 / Accepted: 29 September 2009 / Published: 9 October 2009
Show/Hide Abstract
| Download PDF Full-text (345 KB) Abstract: San-ao decoction (SAD), comprising Herba Ephedrae, Radix et Rhizoma Glycyrrhizae and Seneb Armeniacae Amarum, is one of the most popular traditional Chinese medicine (TCM) formulae for asthma. Peroxisome proliferator-activated receptors (PPARs) areey regulators of lipid and glucose metabolism and have become important therapeutic targets for various deseases, PPARγ activation might exhibit anti-inflammatory properties in different chronic inflammatory processes. The EtOAc fraction of SAD showed a significant effect on PPARγ activation. A simple and rapid method has been established for separation and characterization of the main compounds in the PPARγ-activating fraction of SAD by ultra-fast HPLC coupled with quadropole time-of-flight mass pectrometry (UPLC-Q-TOF/MS). A total of 10 compounds were identified in the activating fraction of SAD, including amygdalin (1), liquiritin (2), 6′-acetyliquiritin (3), liquiritigenin (4), isoliquiritigenin (5), formononetin (6), licoisoflavanone (7), glycycoumarin (8), glycyrol (9) and uercetin (10). The results also characterized formononetin as a predominant component in this fraction. The dose-effect relationship comparison study of formononetin and the EtOAc fraction of SAD by adding formononetin was performed, the results suggested that formononetin was the major component of the EtOAc fraction of SAD responsible for activating PPARγ, and the method will possibly be applied to study the complex biological active constituents of other TCMs.
p. 3952-3963
Received: 25 August 2009; in revised form: 25 September 2009 / Accepted: 27 September 2009 / Published: 9 October 2009
Show/Hide Abstract
| Download PDF Full-text (239 KB) Abstract: An efficient and practical method for the synthesis of indolyl-nitroalkane derivatives catalyzed by N -bromosuccinimide is described. The generality of this method was demonstrated by synthesizing an array of diverse 3-substituted indole derivatives by the reaction of different β-nitrostyrenes with various substituted indoles. Simple reaction conditions accompanied by good yields of indolyl-nitroalkanes are the merits of this methodology.
p. 3964-3974
Received: 23 July 2009; in revised form: 21 August 2009 / Accepted: 15 September 2009 / Published: 9 October 2009
Show/Hide Abstract
| Download PDF Full-text (311 KB) Abstract: Studies on the antioxidant and antimicrobial activities of Mitragyna speciosa leaf extracts are lacking. In this study the antioxidant properties of water, methanolic and alkaloid M. speciosa leaf extracts were evaluated using the DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging method. The amount of total phenolics and flavanoid contents were also estimated. The DPPH IC50 values of the aqueous, alkaloid and methanolic extracts were 213.4, 104.81 and 37.08 μg/mL, respectively. The total phenolic content of the aqueous, alkaloid and methanolic extracts were 66.0 mg, 88.4, 105.6 mg GAE/g, respectively, while the total flavanoid were 28.2, 20.0 and 91.1 mg CAE/g respectively. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to aqueous and alkaloid extract could be possibly be due to its high phenolic content. The aqueous, alkaloid and methanolic extracts were screened for antimicrobial activity. The extracts showed antimicrobial activity against Salmonella typhi and Bacillus subtilis . The minimum inhibitory concentrations (MICs) of extracts determined by the broth dilution method ranged from 3.12 to 6.25 mg/mL. The alkaloid extract was found to be most effective against all of the tested organisms.
p. 3975-3988
Received: 11 August 2009; in revised form: 26 September 2009 / Accepted: 30 September 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (150 KB) Abstract: The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with selenium does not interfere with the positive biological effects of radiation treatment and might constitute a valuable adjuvant therapy option especially in marginally supplied individuals. More recently there were emerging concerns coming up from two large clinical prevention trials (NPC, SELECT), that selenium increases the possible risk of developing diabetes type II. Despite obvious flaws of both studies and good counterarguments, a controversial debate remains on the possible advantage and risks of selenium in cancer prevention. However, in the light of the recent clinical trials the potential benefits of selenium supplementation in tumor patients are undeniable, even if further research is needed.
p. 3989-4021
Received: 24 August 2009; in revised form: 1 October 2009 / Accepted: 10 October 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (737 KB) Abstract: This short review presents new insights on the mechanism and online monitoring using electrospray ionization tandem mass spectrometry (ESI–MS/MS) of Morita–Baylis–Hillman (MBH) reactions. MBH reactions are versatile carbon-carbon organocatalyzed bond forming reactions, making them environmentally friendly due to general organocatalysts employed. The organocatalyst behavior, which controls the transition state and thus the enantioselectivities in the obtained products, is very important in the performance of asymmetric MBH transformations. Some recent techniques and advances in asymmetric transformations are reviwed, as well as online reaction monitoring and analysis of the reaction intermediates. The mechanism accepted nowadays is also review through the insights gained from the use of ESI–MS/MS techniques.
p. 4022-4050
Received: 19 August 2009; in revised form: 22 September 2009 / Accepted: 28 September 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (739 KB) | Abstract: Synthetic polyesters have deeply impacted various biomedical and engineering fields, such as tissue scaffolding and therapeutic delivery. Currently, many applications involving polyesters are being explored with polymers derived from monomers that are endogenous to the human metabolism. Examples of these monomers include glycerol, xylitol, sorbitol, and lactic, sebacic, citric, succinic, α-ketoglutaric, and fumaric acids. In terms of mechanical versatility, crystallinity, hydrophobicity, and biocompatibility, polyesters synthesized partially or completely from these monomers can display a wide range of properties. The flexibility in these macromolecular properties allows for materials to be tailored according to the needs of a particular application. Along with the presence of natural monomers that allows for a high probability of biocompatibility, there is also an added benefit that this class of polyesters is more environmentally friendly than many other materials used in biomedical engineering. While the selection of monomers may be limited by nature, these polymers have produced or have the potential to produce an enormous number of successes in vitro and in vivo .
p. 4051-4064
Received: 14 August 2009; in revised form: 22 September 2009 / Accepted: 29 September 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (186 KB) Abstract: A series of lipoamino acids were synthesized and their neuroprotective effect against brain ischemia induced by oxygen-glucose deprivation (OGD) on rat cerebral slices was evaluated. Among these compounds, N -stearoyl-L-tyrosine (4), N -stearoyl-L-serine (5) and N -stearoyl-L-threonine (6) exhibited good neuroprotective activity. We found that the neuroprotective activity of lipoamino acids depended on the acyl group, the presence of a free carboxylic function and a free hydroxyl group at the branched chain of the amino acids. The results also showed that 5 was the most active compound, protecting rat brain slices against OGD as well as hydrogen peroxide (H2 O2 ) insult at the range of 1–10 M.
p. 4065-4078
Received: 25 August 2009; in revised form: 21 September 2009 / Accepted: 27 September 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (357 KB) Abstract: A solvent-free approach is described for the regioselective synthesis of acylals (1,1-diacetates) in shorter reaction times and higher yields, compared to conventional methodology using solvents. In the protection reaction of the o -hydroxybenzaldehyde the formation of acetyl compounds and anhydro-dimers was observed. The deprotection reaction involves microwave (MW) exposure of diluted reactants in the presence of solid sulphated zirconia (SZ) catalyst that can be easily recovered and reused. The sulphated zirconia was recycled several times without any loss of activity.
p. 4079-4086
Received: 13 August 2009; in revised form: 2 September 2009 / Accepted: 12 October 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (510 KB) Abstract: The molecular combing technique was used to dissociate the nanostructural units of starch granules from the starch fragments after a gelatinization process. With the help of atomic force microscopy (AFM), we observed that some nanostructural chains were just flowing out of the granules. It proves that there are substantive nanostructural units in the starch granules, a phenomenon not previously observed, so these nanostructural units were defined as suspected intermediates. Furthermore, we conclude that blocklets of starch granules are formed through twisting or distortion of nanochains.
p. 4087-4097
Received: 7 August 2009; in revised form: 15 September 2009 / Accepted: 29 September 2009 / Published: 12 October 2009
Show/Hide Abstract
| Download PDF Full-text (667 KB) Abstract: Practical adhesion of rubber to aluminum is measured for various aluminum silanization treatments. In this study, 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-dithiol (TES) was used as the coupling agent for preparing self-assembly monolayers (SAMs) on an aluminum surface. The structure and chemical composition of the SAMs were analyzed using Fourier transform infra-red spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The changes in the surface features of the aluminum surface due to TES treatment were investigated by atomic force microscopy (AFM). The adhesive properties of the silanized aluminum surface and EPDM rubber have been evaluated by a T-peel strength test. The results suggested that the Si-O-Al bonding at aluminum TES interface existed and a TES self-assembly monolayer was formed on the aluminum surface. More than 6.0 KN/m adhesion strength is obtained when the aluminum is silanized with 2.5 mmol/dm3 TES, cured at 160 °C and vulcanized with EPDM rubber at 160 °C for 30 min. It is suggested that the TES self-assembly monolayer is bound to aluminum through its ethoxysilyl functional group, and the thiol function group is strongly crosslinked to EPDM rubber, respectively.
p. 4098-4119
Received: 25 August 2009; in revised form: 23 September 2009 / Accepted: 12 October 2009 / Published: 13 October 2009
Show/Hide Abstract
| Download PDF Full-text (460 KB) Abstract: An overview of the use of 2H -azirines, conjugated nitrosoalkenes and conjugated azoalkenes bearing phosphorus substituents in addition and cycloaddition reactions is presented, focused on strategies for the synthesis of aminophosphonate and aminophosphine oxide derivatives.
p. 4120-4135
Received: 11 August 2009; in revised form: 21 September 2009 / Accepted: 14 October 2009 / Published: 14 October 2009
Show/Hide Abstract
| Download PDF Full-text (147 KB) Abstract: This paper describes the synthesis and in vitro antimalarial activity against a P. falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of the tested compounds showed an IC50 lower than 1 μM. These compounds were also tested for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic option for the treatment of malaria.
p. 4136-4146
Received: 5 August 2009; in revised form: 25 August 2009 / Accepted: 30 September 2009 / Published: 15 October 2009
Show/Hide Abstract
| Download PDF Full-text (200 KB) Abstract: This report describes the characterization of a series of commercially available procyanidin standards ranging from dimers DP = 2 to decamers DP = 10 for the determination of procyanidins from cocoa and chocolate. Using a combination of HPLC with fluorescence detection and MALDI-TOF mass spectrometry, the purity of each standard was determined and these data were used to determine relative response factors. These response factors were compared with other response factors obtained from published methods. Data comparing the procyanidin analysis of a commercially available US dark chocolate calculated using each of the calibration methods indicates divergent results and demonstrate that previous methods may significantly underreport the procyanidins in cocoa-containing products. These results have far reaching implications because the previous calibration methods have been used to develop data for a variety of scientific reports, including food databases and clinical studies.
p. 4147-4158
Received: 14 August 2009; in revised form: 2 October 2009 / Accepted: 14 October 2009 / Published: 16 October 2009
Show/Hide Abstract
| Download PDF Full-text (327 KB) Abstract: X-ray structures of two compounds isolated from wood knots of coniferous trees, namely dihydrokaempferol (3,5,8,13-tetrahydroxyflavanon) and lariciresinol (3,14-dimetoxy-7,10-epoxylignan-4,15,19-triol), are presented here. Diffraction data for the Dihydrokaempferol crystals were collected on a CAD4 diffractometer and on a synchrotron for the lariciresinol crystal. The investigated compounds inhibit lipid peroxidation and lariciresinol is additionally a good scavenger of superoxide radicals. The structural data presented in this work provide a useful basis for designing more active compounds with potential use as antioxidants.
p. 4159-4165
Received: 10 September 2009; in revised form: 16 October 2009 / Accepted: 16 October 2009 / Published: 16 October 2009
Show/Hide Abstract
| Download PDF Full-text (118 KB) Abstract: This study examined the feasibility of using Trametes sp. grown under drought conditions to catalyze the covalent cross-linking of ferulated arabinoxylans. The rate of polymerization of ferulated arabinoxylans solutions at 0.5% (w/v) was dose dependent on the laccase concentration in the system. Above 1.2 nkat laccase/mg ferulated arabinoxylan, the rate of cross-linking reached a plateau, suggesting that the reaction reached saturation. For 2% (w/v) ferulated arabinoxylans treated with laccase (1.6 nkat/mg ferulated arabinoxylan), stable gels were formed after 4 h at 25 °C, with cross-linking contents (diferulic and triferulic acid) contents of 0.03 and 0.015 μg/mg ferulated arabinoxylan, respectively. This study demonstrated that Trametes sp. can be a source of biopolymer cross-linking enzymes like laccase.
p. 4166-4179
Received: 1 September 2009; in revised form: 30 September 2009 / Accepted: 12 October 2009 / Published: 19 October 2009
Show/Hide Abstract
| Download PDF Full-text (381 KB) Abstract: A series of novel 2-phenylaminopyrimidine (PAP) derivatives structurally related to STI-571 were designed and synthesized. The abilities of these compounds to inhibit proliferation were tested in human chronic myeloid leukemia K562 cells. (E )-3-(2-bromophenyl)-N -[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)phenyl]acrylamide(12d) was the most effective cell growth inhibitor and was 3-fold more potent than STI-571.
p. 4180-4189
Received: 8 September 2009; in revised form: 1 October 2009 / Accepted: 13 October 2009 / Published: 20 October 2009
Show/Hide Abstract
| Download PDF Full-text (458 KB) Abstract: The condensation of chlorides of substituted pyrazinecarboxylic acids with ringsubstituted anilines yielded twelve substituted pyrazinecarboxylic acid amides. The synthetic approach, analytical, and lipophilicity data of the newly synthesized compounds are presented. Two antituberculosis assays were used. Firstly, the antimycobacterial activity against four different Mycobacterium strains in a series of pyrazine derivatives was investigated. Secondly, the antimycobacterial evaluation was performed at the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) program. Interesting in vitro antimycobacterial activity was found, N -(3-iodo-4-methylphenyl) pyrazine-2-carboxamide (9) was most active derivative compound against M. tuberculosis (MIC < 2.0 μmol/L), while another iodo derivative 5-tert -butyl-6-chloro-N -(3-iodo-4-methyl-phenyl)pyrazine-2-carboxamide (12) was the most active compound in the TAACF antituberculosis screening program (IC90 = 0.819 μg/mL).
p. 4190-4196
Received: 21 September 2009; in revised form: 12 October 2009 / Accepted: 20 October 2009 / Published: 20 October 2009
Show/Hide Abstract
| Download PDF Full-text (178 KB) Abstract: Elsholtzia rugulosa Hemsl. is known in China as a local herbal tea, medicinal herb and honey plant. Chemical examination of E. rugulosa led to the isolation of two new flavonoid glycosides, apigenin 4'-O -α -D-glucopyranoside (1) and 5,7,3',4'-tetrahydroxy-5'-C-prenylflavone-7-O -β -D-glucopyranoside (2), together with nine known flavonoids. Their structures were elucidated on the basis of spectroscopic evidence.
p. 4197-4212
Received: 21 September 2009; in revised form: 9 October 2009 / Accepted: 19 October 2009 / Published: 20 October 2009
Show/Hide Abstract
| Download PDF Full-text (270 KB) Abstract: Some [(5Z )-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acids were prepared as potential antifungal compounds. The general synthetic approach to all synthesized compounds is presented. Lipophilicity of all the discussed rhodanine-3-acetic acid derivatives was analyzed using a reversed phase high performance liquid chromatography (RP-HPLC) method. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C18 stationary RP column. The RP-HPLC retention parameter log k (the logarithm of the capacity factor k ) is compared with log P values calculated in silico . All compounds were evaluated for antifungal effects against selected fungal species. Most compounds exhibited no interesting activity, and only {(5Z )-[4-oxo-5-(pyridin-2- ylmethylidene)-2-thioxo-1,3-thiazolidin-3-yl]}acetic acid strongly inhibited the growth of Candida tropicalis 156, Candida krusei E 28, Candida glabrata 20/I and Trichosporon asahii 1188.
(This article belongs to the Special Issue
ECSOC-12 )
p. 4213-4230
Received: 6 October 2009; in revised form: 20 October 2009 / Accepted: 20 October 2009 / Published: 20 October 2009
Show/Hide Abstract
| Download PDF Full-text (481 KB) Abstract: Deeper knowledge of the potentiality of aromatic plants can provide results of economic importance for food and pharmacological industry. The essential oils of seven Lamiaceae species were analyzed by gas chromatography-mass spectrometry and assayed for their antibacterial, antifungal and mutagenic activities. Monoterpenes in the oils ranged between 82.47% (hyssop oil) and 97.48% (thyme oil), being mainly represented by oxygenated compounds. The antibacterial activity was evaluated against six pathogenic and five non-pathogenic bacterial strains. Oregano and thyme oils showed the strongest antibacterial activity against the pathogenic ones. The antifungal activity was evaluated against six fungal strains of agrifood interest: the oils tested exhibited variable degrees of activity. Two Salmonella typhimurium strains were used to assess the possible mutagenic activity. No oil showed mutagenic activity. Data obtained let us hypothesise that the use of essential oils could be a viable and safe way to decrease the utilisation of synthetic food preservatives. Further research is needed to obtain information regarding the practical effectiveness of essential oils to prevent the growth of food borne and spoiling microbes under specific application conditions.
p. 4231-4245
Received: 18 September 2009; in revised form: 13 October 2009 / Accepted: 19 October 2009 / Published: 22 October 2009
Show/Hide Abstract
| Download PDF Full-text (139 KB) Abstract: Two different types of soft alkyl ether prodrugs incorporating ethyleneoxy groups into the promoiety have been synthesized for a model phenol (acetaminophen, APAP): alkyloxycarbonyloxymethyl type (AOCOM) and N -alkyl-N -alkyloxycarbonyl-aminomethyl type (NANAOCAM). The solubilities in isopropyl myristate, SIPM , and water, SAQ , partition coefficients between IPM and pH 4.0 buffer, KIPM:4.0 , and the delivery of total species containing APAP through hairless mouse skin from IPM, JMMIPM , have been measured for the prodrugs. The JMMIPM values were accurately predicted by the Roberts-Sloan (RS) equation. Only modest increases in JMMIPM were realized (about 1.4 times) by each type. The only prodrug that was more water soluble and more lipid soluble than APAP did not improve JMMIPM of APAP. This result may be due to the strong association of water molecules with the ethyleneoxy groups, and especially the triethyleneoxy derivative, which dramatically increases the molecular weight and depresses JMMIPM .
(This article belongs to the Special Issue
Prodrugs )
p. 4246-4265
Received: 21 September 2009; in revised form: 13 October 2009 / Accepted: 21 October 2009 / Published: 23 October 2009
Show/Hide Abstract
| Download PDF Full-text (194 KB) Abstract: In this study, series of ring-substituted 2-styrylquinazolin-4(3H )-one and 4-chloro-2-styrylquinazoline derivatives were prepared. The syntheses of the discussed compounds are presented. The compounds were analyzed by RP-HPLC to determine lipophilicity. They were tested for their inhibitory activity on photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains. Several compounds showed biological activity comparable with or higher than that of the standard isoniazid. It was found that the electronic properties of the R substituent, and not the total lipophilicity of the compound, were decisive for the photosynthesis-inhibiting activity of tested compounds.
p. 4266-4274
Received: 27 August 2009; in revised form: 21 October 2009 / Accepted: 23 October 2009 / Published: 23 October 2009
Show/Hide Abstract
| Download PDF Full-text (330 KB) Abstract: The title compound, 5-(4,5-dimethylthio-1,3-dithiol-2-ylidene)-1,3-diaza-2,4,6-trithiapentalene (4,5-dimethylthio [1,2,5]thiadiazolotetrathiafulvalene, molecular formula C8 H6 N2 S7 ) crystallizes in the P21 /n space group with one molecule in the asymmetric unit. The molecular framework is planar within 0.19 Å. The molecules form a head-to-tail type of π -stacking dimer with an interplanar distance is 3.50(1) Å, where methylthio groups face away from each other. The molecules are also linked by weak intermolecular S···S heteroatom interactions [3.497(1) and 3.572(1) Å] to construct a unique one-dimensional molecular tape structure.
p. 4275-4283
Received: 31 August 2009; in revised form: 26 September 2009 / Accepted: 16 October 2009 / Published: 23 October 2009
Show/Hide Abstract
| Download PDF Full-text (192 KB) Abstract: Preparation of (S )-1-chloro-2-octanol and (S )-1-bromo-2-octanol was carried out by the enzymatic hydrolysis of halohydrin palmitates using biocatalysts. Halohydrin palmitates were prepared by various methods from palmitic acid and 1,2-octanediol. A tandem hydrolysis was carried out using lipases from Candida antarctica (Novozym® 435), Rhizomucor miehei (Lipozyme IM), and “resting cells” from a Rhizopus oryzae strain that was not mycotoxigenic. The influence of the enzyme and the reaction medium on the selective hydrolysis of isomeric mixtures of halohydrin esters is described. Novozym® 435 allowed preparation of (S )-1-chloro-2-octanol and (S )-1-bromo-2-octanol after 1–3 h of reaction at 40 °C in [BMIM][PF6 ].
p. 4284-4299
Received: 30 September 2009; in revised form: 22 October 2009 / Accepted: 23 October 2009 / Published: 23 October 2009
Show/Hide Abstract
| Download PDF Full-text (332 KB) Abstract: This article reviews the nanomaterials that have been prepared to date by pulsed sonoelectrochemistry. The majority of nanomaterials produced by this method are pure metals such as silver, palladium, platinum, zinc, nickel and gold, but more recently the syntheses have been extended to include the preparation of nanosized metallic alloys and metal oxide semiconductors. A major advantage of this methodology is that the shape andsize of the nanoparticles can be adjusted by varying the operating parameters which include ultrasonic power, current density, deposition potential and the ultrasonic vs electrochemical pulse times. Together with these, it is also possible to adjust the pH, temperature and composition of the electrolyte in the sonoelectrochemistry cell.
Select/unselect all
Displaying article 1-33
Export citation of selected articles as:
Plain Text
BibTeX
BibTeX (without abstracts)
Endnote
Endnote (without abstracts)
Tab-delimited
PubMed XML
DOAJ XML
AGRIS XML