Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Molecules, Volume 14, Issue 8 (August 2009), Pages 2684-3114

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-33
Export citation of selected articles as:

Research

Jump to: Review, Other

Open AccessArticle Physical Carboxymethylscleroglucan/Calcium Ion Hydrogels as Modified Drug Delivery Systems in Topical Formulations
Molecules 2009, 14(8), 2684-2698; doi:10.3390/molecules14082684
Received: 29 June 2009 / Revised: 16 July 2009 / Accepted: 21 July 2009 / Published: 24 July 2009
Cited by 9 | PDF Full-text (417 KB)
Abstract
A carboxymethyl derivative of scleroglucan (Scl-CM) with a 65±5% carboxylic group degree of derivatization (DD) was recently synthesized and characterized. Aqueous solutions of the polymer underwent to a sharp transition toward a gel like behaviour in the presence of divalent ions such [...] Read more.
A carboxymethyl derivative of scleroglucan (Scl-CM) with a 65±5% carboxylic group degree of derivatization (DD) was recently synthesized and characterized. Aqueous solutions of the polymer underwent to a sharp transition toward a gel like behaviour in the presence of divalent ions such as Ca+2. Physical hydrogels with different Scl-CM/Ca+2 ratios were prepared and characterized for their rheological behaviour. Their potential as drug delivery systems was also evaluated. To this end three non steroidal anti-inflammatory drugs (NSAIDs) were loaded into the hydrogels obtained with 2% w/v solution of Scl-CM and 0.05 and 0.1 M CaCl2. The release rate of the drugs was critically related to the salt concentration. By an appropriate combination of the hydrogels prepared using different amounts of salt, it was possible to obtain a system able to release diclofenac with zero-order kinetics. Primary skin irritation tests showed a good biocompatibility of the new polymer, as well as of its hydrogels. These results suggest a potential of the new hydrogels for the development of modified delivery systems in topical formulations. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Open AccessArticle Influence of Different Polymer Types on the Overall Release Mechanism in Hydrophilic Matrix Tablets
Molecules 2009, 14(8), 2699-2716; doi:10.3390/molecules14082699
Received: 25 June 2009 / Revised: 10 July 2009 / Accepted: 15 July 2009 / Published: 24 July 2009
Cited by 7 | PDF Full-text (536 KB)
Abstract
The effect of three different types of polymer chain structures on the polymer release from hydrophilic matrix tablets was investigated by comparing a synthetic semi-crystalline linear polymer (PEO), a branched amorphous polysaccharide (dextran) and an amorphous substituted cellulose derivative (HPMC). The polymer [...] Read more.
The effect of three different types of polymer chain structures on the polymer release from hydrophilic matrix tablets was investigated by comparing a synthetic semi-crystalline linear polymer (PEO), a branched amorphous polysaccharide (dextran) and an amorphous substituted cellulose derivative (HPMC). The polymer release rates for tablets containing mixtures of high and low molecular weight grades in different ratios were determined by using a modified USP II method and a SEC-RI chromatography system. The results showed that independent of polymer type: (i) plots of the release versus time had similar shapes, (ii) the release of long and short polymer chains was equal and no fractionation occurred during the release and (iii) the release rate could be related to the average intrinsic viscosity of the polymer mixtures. This confirms the hypothesis that the release rate can be related to a constant viscosity on the surface of the hydrophilic matrix tablet and that it is valid for all the investigated polymers. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Open AccessArticle Headspace, Volatile and Semi-Volatile Organic Compounds Diversity and Radical Scavenging Activity of Ultrasonic Solvent Extracts from Amorpha fruticosa Honey Samples
Molecules 2009, 14(8), 2717-2728; doi:10.3390/molecules14082717
Received: 10 July 2009 / Revised: 23 July 2009 / Accepted: 27 July 2009 / Published: 27 July 2009
Cited by 22 | PDF Full-text (430 KB)
Abstract
Volatile organic compounds of Amorpha fruticosa honey samples were isolated by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry analyses (GC, GC-MS), in order to obtain complementary data for overall characterization of the honey [...] Read more.
Volatile organic compounds of Amorpha fruticosa honey samples were isolated by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry analyses (GC, GC-MS), in order to obtain complementary data for overall characterization of the honey aroma. The headspace of the honey was dominated by 2-phenylethanol (38.3–58.4%), while other major compounds were trans- and cis-linalool oxides, benzaldehyde and benzyl alcohol. 2-Phenylethanol (10.5–16.8%) and methyl syringate (5.8–8.2%) were the major compounds of ultrasonic solvent extracts, with an array of small percentages of linalool, benzene and benzoic acid derivatives, aliphatic hydrocarbons and alcohols, furan derivatives and others. The scavenging ability of the series of concentrations of the honey ultrasonic solvent extracts and the corresponding honey samples was tested by a DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Approximately 25 times lower concentration ranges (up to 2 g/L) of the extracts exhibited significantly higher free radical scavenging potential with respect to the honey samples. Full article
(This article belongs to the Special Issue Molecular Diversity Feature Papers)
Open AccessArticle Coumarins from Angelica Lucida L. - Antibacterial Activities
Molecules 2009, 14(8), 2729-2734; doi:10.3390/molecules14082729
Received: 1 July 2009 / Revised: 20 July 2009 / Accepted: 20 July 2009 / Published: 27 July 2009
Cited by 22 | PDF Full-text (212 KB)
Abstract
The first phytochemical investigation of the fruits of Angelica lucida has led to the isolation and characterization of five known coumarins (imperatorin, isoimperatorin, heraclenol, oxypeucedanin hydrate and heraclenin). All isolated compounds were identified by means of spectral and literature data. The extracts [...] Read more.
The first phytochemical investigation of the fruits of Angelica lucida has led to the isolation and characterization of five known coumarins (imperatorin, isoimperatorin, heraclenol, oxypeucedanin hydrate and heraclenin). All isolated compounds were identified by means of spectral and literature data. The extracts and the isolated constituents from A. lucida have been also evaluated for their antimicrobial activity against six Gram positive and negative bacteria, two oral pathogens and three human pathogenic fungi, exhibiting an interesting antimicrobial profile. Full article
(This article belongs to the Special Issue Coumarins and Xanthones)
Figures

Open AccessArticle Chemical Composition and Antimicrobial Activity of the Essential Oils from Three Chemotypes of Origanum vulgare L. ssp. hirtum (Link) Ietswaart Growing Wild in Campania (Southern Italy)
Molecules 2009, 14(8), 2735-2746; doi:10.3390/molecules14082735
Received: 29 June 2009 / Revised: 20 July 2009 / Accepted: 22 July 2009 / Published: 27 July 2009
Cited by 43 | PDF Full-text (127 KB)
Abstract
Essential oils obtained from inflorescences of three Origanum vulgare L.ssp. hirtum (Link) Ietswaart samples, growing wild in different locations in Campania (Southern Italy), were analysed. Three chemotypes were found: the first, with a prevalence of carvacrol/thymol; the second, characterized by the prevalence [...] Read more.
Essential oils obtained from inflorescences of three Origanum vulgare L.ssp. hirtum (Link) Ietswaart samples, growing wild in different locations in Campania (Southern Italy), were analysed. Three chemotypes were found: the first, with a prevalence of carvacrol/thymol; the second, characterized by the prevalence of thymol/α-terpineol; the third, featuring a prevalence of linalyl acetate and linalool. This chemical study attempts to provide a contribution in shedding light on the relationship between chemical composition and biotypes and/or chemotypes in Origanum vulgare ssp. hirtum. The essential oils were also evaluated for their antibacterial activity against 10 selected microorganisms. The data obtained contribute to the future view to use the essential oils as natural preservatives for food products, due to their positive effect on their safety and shelf life. Full article
Open AccessArticle Wet Aerobic Oxidation of Lignin into Aromatic Aldehydes Catalysed by a Perovskite-type Oxide: LaFe1-xCuxO3 (x=0, 0.1, 0.2)
Molecules 2009, 14(8), 2747-2757; doi:10.3390/molecules14082747
Received: 8 June 2009 / Revised: 7 July 2009 / Accepted: 23 July 2009 / Published: 27 July 2009
Cited by 34 | PDF Full-text (308 KB)
Abstract
The perovskite-type oxide catalyst LaFe1-xCuxO3 (x=0, 0.1, 0.2) was prepared by the sol–gel method, and tested as a catalyst in the wet aerobic oxidation (WAO) of lignin into aromatic aldehydes. The lignin conversion and the yield of [...] Read more.
The perovskite-type oxide catalyst LaFe1-xCuxO3 (x=0, 0.1, 0.2) was prepared by the sol–gel method, and tested as a catalyst in the wet aerobic oxidation (WAO) of lignin into aromatic aldehydes. The lignin conversion and the yield of each aromatic aldehyde were significantly enhanced in the catalytic process, compared with the non-catalyzed process. Moreover, it was shown that the stability of activity and structure of LaFe1-xCuxO3 (x=0, 0.1, 0.2) remained nearly unchanged after a series of successive recyclings of the catalytic reactions, indicating it was an efficient and recyclable heterogeneous catalyst for the conversion of lignin into aromatic aldehydes in the WAO process. Full article
(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)
Figures

Open AccessArticle New Synthesis and Antiparasitic Activity of Model 5-Aryl-1-methyl-4-nitroimidazoles
Molecules 2009, 14(8), 2758-2767; doi:10.3390/molecules14082758
Received: 3 July 2009 / Revised: 19 July 2009 / Accepted: 23 July 2009 / Published: 27 July 2009
Cited by 6 | PDF Full-text (182 KB)
Abstract
A number of 5-aryl-1-methyl-4-nitroimidazoles 5a-f have been synthesized in good yields by the Suzuki coupling reaction between 5-chloro-1-methyl-4-nitroimidazole (3) and arylboronic acids 4a-f, aided by dichlorobis-(triphenylphosphine)palladium(II), K2CO3, and tetrabutylammonium bromide in water at 70-80 °C. Compounds 5a-f were characterized [...] Read more.
A number of 5-aryl-1-methyl-4-nitroimidazoles 5a-f have been synthesized in good yields by the Suzuki coupling reaction between 5-chloro-1-methyl-4-nitroimidazole (3) and arylboronic acids 4a-f, aided by dichlorobis-(triphenylphosphine)palladium(II), K2CO3, and tetrabutylammonium bromide in water at 70-80 °C. Compounds 5a-f were characterized by elemental analysis, NMR and MS spectral data. On the basis of in vitro screening data, 5-(3-chlorophenyl)-1-methyl-4-nitro-1H-imidazole (5f)exhibited potent lethal activity against Entamoeba histolytica and Giardia intestinalis with IC50 = 1.47 µM/mL, a value lower by a factor of two than that of the standard drug, metronidazole. The boosted activity of 5f was not accompanied by any increased cytotoxicity.The rest of the series also exhibited potent antiparasitic activity with IC50 valuesin the 1.72-4.43 µM/mL range. The cytotoxicity of the derivatives 5c and 5e was increased compared to the precursor compound, metronidazole, although they remain non-cytotoxic at concentrations much higher than the antiparasitic concentration of the two derivatives. Full article
Figures

Open AccessArticle Synthesis of N-Substituted 5-Iodouracils as Antimicrobial and Anticancer Agents
Molecules 2009, 14(8), 2768-2779; doi:10.3390/molecules14082768
Received: 6 July 2009 / Revised: 15 July 2009 / Accepted: 27 July 2009 / Published: 27 July 2009
Cited by 17 | PDF Full-text (502 KB)
Abstract
This study reports the synthesis of some substituted 5-iodouracils and their bioactivities. Alkylation of 5-iodouracils gave predominately N1-substituted-(R)-5-iodouracil compounds 7a-d (R = n-C4H9, s-C4H9, CH2C6H11, CH [...] Read more.
This study reports the synthesis of some substituted 5-iodouracils and their bioactivities. Alkylation of 5-iodouracils gave predominately N1-substituted-(R)-5-iodouracil compounds 7a-d (R = n-C4H9, s-C4H9, CH2C6H11, CH2C6H5) together with N1,N3-disubstituted (R) analogs 8a-b (R = n-C4H9, CH2C6H11). Their antimicrobial activity was tested against 27 strains of microorganisms using the agar dilution method. The analogs 7a, 7c and 7d displayed 25-50% inhibition against Branhamella catarrhalis, Neisseria mucosa and Streptococcus pyogenes at 0.128 mg/mL. No antimalarial activity was detected for any of the analogs when tested against Plasmodium falciparum (T9.94). Their anticancer activity was also examined. Cyclohexylmethyl analogs 7c and 8b inhibited the growth of HepG2 cells. Significantly, N1,N3-dicyclohexylmethyl analog 8b displayed the most potent anticancer activity, with an IC50 of 16.5 mg/mL. These 5-iodouracil analogs represent a new group of anticancer and antibacterial agents with potential for development for medicinal applications. Full article
Figures

Open AccessArticle Synthesis and Olfactory Evaluation of Bulky Moiety-Modified Analogues to the Sandalwood Odorant Polysantol®
Molecules 2009, 14(8), 2780-2800; doi:10.3390/molecules14082780
Received: 17 June 2009 / Revised: 21 July 2009 / Accepted: 27 July 2009 / Published: 28 July 2009
Cited by 3 | PDF Full-text (390 KB)
Abstract
Five new bulky moiety-modified analogues of the sandalwood odorant Polysantol® have been synthesized by aldol condensation of appropriate aldehydes with butanone, deconjugative α-methylation of the resulting α,β-unsaturated ketones, and reduction of the corresponding β,γ-unsaturated ketones. The final compounds were evaluated organoleptically [...] Read more.
Five new bulky moiety-modified analogues of the sandalwood odorant Polysantol® have been synthesized by aldol condensation of appropriate aldehydes with butanone, deconjugative α-methylation of the resulting α,β-unsaturated ketones, and reduction of the corresponding β,γ-unsaturated ketones. The final compounds were evaluated organoleptically and one of them seemed to be of special interest for its natural sandalwood scent. Full article
Figures

Open AccessCommunication Enantiopure Derivatives of Aza-Baylis-Hillman Adducts by Subsequent SN′-SN′ Reactions of Acylcarbamates Bearing a Chiral Auxiliary
Molecules 2009, 14(8), 2824-2835; doi:10.3390/molecules14082824
Received: 7 July 2009 / Revised: 22 July 2009 / Accepted: 30 July 2009 / Published: 30 July 2009
PDF Full-text (257 KB)
Abstract Reactions of(4S,5R)-1-(3,4-Dimethyl-2-oxo-5-phenylimidazolidine)carbonyl-isocyanate (4) with appropriate Baylis-Hillman adducts 5 gave the corresponding acyl carbamates 6,7 as equimolar diastereomeric mixtures. These mixtures were treated with DABCO, to afford with moderate diastereoselection easily separable [2-(3",4"-dimethyl-2"-oxo-5"-phenylimidazolidine-1-carboxamido)(aryl)methyl]acrylates 8 and 9. Full article
(This article belongs to the Special Issue Baylis-Hillman Reaction and Related Processes)
Figures

Open AccessArticle Efficient Microwave Assisted Syntheses of 2,5-Diketopiperazines in Aqueous Media
Molecules 2009, 14(8), 2836-2849; doi:10.3390/molecules14082836
Received: 23 June 2009 / Revised: 21 July 2009 / Accepted: 23 July 2009 / Published: 31 July 2009
Cited by 15 | PDF Full-text (211 KB)
Abstract
Aqueous in situ one-pot N-Boc-deprotection-cyclization of -Boc-dipeptidyl-tert-butyl and methyl esters under microwave irradiation afforded 2,5-diketopiperazines (DKPs) in excellent yields. This protocol is rapid, safe, environmentally friendly, and highly efficient, and showed that the tert-butoxy moiety is also an excellent leaving [...] Read more.
Aqueous in situ one-pot N-Boc-deprotection-cyclization of -Boc-dipeptidyl-tert-butyl and methyl esters under microwave irradiation afforded 2,5-diketopiperazines (DKPs) in excellent yields. This protocol is rapid, safe, environmentally friendly, and highly efficient, and showed that the tert-butoxy moiety is also an excellent leaving group for these cyclizations. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Figures

Open AccessArticle (+)-N-(2-Hydroxypropyl)lindcarpine: A New Cytotoxic Aporphine Isolated from Actinodaphne pruinosa Nees
Molecules 2009, 14(8), 2850-2856; doi:10.3390/molecules14082850
Received: 30 June 2009 / Revised: 22 July 2009 / Accepted: 27 July 2009 / Published: 31 July 2009
Cited by 7 | PDF Full-text (381 KB) | HTML Full-text | XML Full-text
Abstract
Onenewalkaloid; (+)-N-(2-hydroxypropyl)lindcarpine (1),together with four known aporphine alkaloids, (+)-boldine (2) (+)-norboldine (3), (+)-lindcarpine (4) and (+)-methyllindcarpine (5) were isolated from the stem bark of Actinodaphne pruinosa Nees (Lauraceae). (+)-N-(2-Hydroxypropyl)lindcarpine (1) exhibited cytotoxic activity against P-388 murine leukemia cells [...] Read more.
Onenewalkaloid; (+)-N-(2-hydroxypropyl)lindcarpine (1),together with four known aporphine alkaloids, (+)-boldine (2) (+)-norboldine (3), (+)-lindcarpine (4) and (+)-methyllindcarpine (5) were isolated from the stem bark of Actinodaphne pruinosa Nees (Lauraceae). (+)-N-(2-Hydroxypropyl)lindcarpine (1) exhibited cytotoxic activity against P-388 murine leukemia cells with an IC50 value of 3.9 μg/mL. Structural elucidation of all the compounds were performed by spectral methods such as 1D- and 2D- NMR, IR, UV, and HRESIMS. Full article
(This article belongs to the Special Issue Aporphines and Oxoaporphines)
Figures

Open AccessArticle Quinones as Key Intermediates in Natural Products Synthesis. Syntheses of Bioactive Xanthones from Hypericum perforatum
Molecules 2009, 14(8), 2857-2861; doi:10.3390/molecules14082857
Received: 30 July 2009 / Revised: 23 July 2009 / Accepted: 29 July 2009 / Published: 3 August 2009
Cited by 4 | PDF Full-text (63 KB) | HTML Full-text | XML Full-text
Abstract Two bioactive xanthones from Hypericum perforatum have been synthesized by direct routes. Benzo[c]xanthone 5 can be prepared from intermediate 4. Full article
Figures

Open AccessArticle A New Sesquiterpene from the Fruits of Daucus carota L.
Molecules 2009, 14(8), 2862-2867; doi:10.3390/molecules14082862
Received: 6 July 2009 / Revised: 27 July 2009 / Accepted: 29 July 2009 / Published: 3 August 2009
Cited by 8 | PDF Full-text (117 KB) | HTML Full-text | XML Full-text | Correction | Supplementary Files
Abstract
Phytochemical investigation of the fruits of Daucus carota L. resulted in the isolation of a new sesquiterpene named as daucucarotol (1). Its structure was elucidated on the basis of 1D and 2D NMR experiments, coupled with MS studies. To our knowledge, compound [...] Read more.
Phytochemical investigation of the fruits of Daucus carota L. resulted in the isolation of a new sesquiterpene named as daucucarotol (1). Its structure was elucidated on the basis of 1D and 2D NMR experiments, coupled with MS studies. To our knowledge, compound 1 is the first example for a natural eudesmane sesquiterpene with a hydroxymethyl group located at a methine carbon rather than a usual quaternary carbon in the two fused six-membered ringsystems. Full article
Figures

Open AccessArticle Chemical Composition of the Essential Oils of Cyperus rotundus L. from South Africa
Molecules 2009, 14(8), 2909-2917; doi:10.3390/molecules14082909
Received: 12 June 2009 / Revised: 31 July 2009 / Accepted: 6 August 2009 / Published: 6 August 2009
Cited by 42 | PDF Full-text (118 KB) | HTML Full-text | XML Full-text
Abstract
The essential oils from the rhizomes of Cyperus rotundus L. collected from two different locations (Empangeni-A and KwaDlangezwa-B; both in the Kwa-Zulu Natal Province of South Africa) were obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Forty-one and 43 components [...] Read more.
The essential oils from the rhizomes of Cyperus rotundus L. collected from two different locations (Empangeni-A and KwaDlangezwa-B; both in the Kwa-Zulu Natal Province of South Africa) were obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Forty-one and 43 components were identified, representing 89.9% and 92.0% of sample A and sample B, respectively. α-Cyperone (11.0%), myrtenol (7.9%), caryophyllene oxide (5.4%) and β-pinene (5.3%) were major compounds in the oil of sample A. The main constituents of the oil of sample B were β-pinene (11.3%), α-pinene (10.8%), α- cyperone (7.9%), myrtenol (7.1%) and α-selinene (6.6%). Full article
Open AccessArticle Cross-Cyclotrimerization with Two Nitriles as a Synthetic Pathway to Unsymmetrically 3,3’-Disubstituted bis(Tetrahydroisoquinolines)
Molecules 2009, 14(8), 2918-2926; doi:10.3390/molecules14082918
Received: 10 July 2009 / Revised: 31 July 2009 / Accepted: 3 August 2009 / Published: 10 August 2009
Cited by 14 | PDF Full-text (233 KB) | HTML Full-text | XML Full-text
Abstract Microwave assisted CpCo(CO)2 catalyzed cross-cyclotrimerizations of 1,7,9,15-hexadecatetrayne with two different nitriles to give unsymmetrically substituted bis(tetrahydroisoquinolines) was studied. The reaction proceeded with a range of alkyl and aryl nitriles with reasonable isolated yields. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Figures

Open AccessCommunication Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS
Molecules 2009, 14(8), 2927-2934; doi:10.3390/molecules14082927
Received: 22 June 2009 / Revised: 13 July 2009 / Accepted: 27 July 2009 / Published: 10 August 2009
Cited by 5 | PDF Full-text (267 KB) | HTML Full-text | XML Full-text
Abstract
The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented [...] Read more.
The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextraction (SPME) method. This component had a mass spectrum with a characteristic ion peak at m/z 85 (100%) and a linear retention index (RI) of 2,023 on a DB Wax column, consistent with those of an authentic sample of γ-nonalactone. The odor characterization of a strong, sweet, coconut-like aroma of this compound was also validated by GC-O comparison with the authentic compound. Full article
Open AccessArticle Catalytic Epoxidation of a Technical Mixture of Methyl Oleate and Methyl Linoleate in Ionic Liquids Using MoO(O2)2•2QOH (QOH = 8-quinilinol) as Catalyst and NaHCO3 as co-Catalyst
Molecules 2009, 14(8), 2935-2946; doi:10.3390/molecules14082935
Received: 2 July 2009 / Revised: 3 August 2009 / Accepted: 5 August 2009 / Published: 10 August 2009
Cited by 19 | PDF Full-text (271 KB) | HTML Full-text | XML Full-text
Abstract
The oxo-diperoxo molybdenum(VI) complex MoO(O2)2•2QOH (QOH = 8-quinilinol) was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs) [bmim][BF4], [hydemim][BF4], and [bmim][PF6] were characterized by 1H-NMR [...] Read more.
The oxo-diperoxo molybdenum(VI) complex MoO(O2)2•2QOH (QOH = 8-quinilinol) was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs) [bmim][BF4], [hydemim][BF4], and [bmim][PF6] were characterized by 1H-NMR and UV-Vis spectra. The epoxidation of a technical mixture of methyl oleate and methyl linoleate with H2O2, in [bmim][BF4], [hydemim][BF4] and [bmim][PF6], catalyzed by MoO(O2)2•2QOH (QOH = 8-quinilinol) and with NaHCO3 as co-catalyst has been studied for the first time. It was found that high conversions of methyl oleate and methyl linoleate to their respective oxidation products, as well as the total selectivity of their oxidation products to oxirane in [hydemim][BF4] were obtained. Also, the IL phases containing the Mo(VI) catalyst can be readily recycled by washing with diethyl ether and drying, and the Mo(VI) catalyst can be reused at least five times. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessArticle Antioxidant Activity of Some Plant Extracts Towards Xanthine Oxidase, Lipoxygenase and Tyrosinase
Molecules 2009, 14(8), 2947-2958; doi:10.3390/molecules14082947
Received: 22 May 2009 / Revised: 9 July 2009 / Accepted: 22 July 2009 / Published: 10 August 2009
Cited by 27 | PDF Full-text (225 KB) | HTML Full-text | XML Full-text
Abstract
Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. [...] Read more.
Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. This was performed by assessing the activities of lipoxygenase, xanthine oxidase and tyrosinase following incubation with extracts from these plants. A further aim was to use HPLC-DAD and tyrosinase to chromatographically identify the antioxidative constituents obtained from an extract exhibiting strong antioxidative properties. The acetone extracts of 27 cultivated plant species from Taiwan were tested for antioxidant activities towards xanthine oxidase, tyrosinase and lipoxygenase using spectrophotometric assays. Koelreuteria henryi, Prunus campanulata, and Rhodiola rosea showed the highest xanthine oxidase inhibitory activities. Camellia sinensis, Rhodiola rosea, and Koelreuteria henryi exhibited good tyrosinase inhibitory activities and potent anti-lipoxygenase activities. As Koelreuteria henryi had notable significant inhibitory activities towards xanthine oxidase, tyrosinase, and lipoxygenase, it was further tested with tyrosinase and HPLC-DAD. The results from this part of the study revealed that the more powerful the antioxidant capability of the extracted component, the greater the decrease in peak height obtained after reacting with tyrosinase. Additional studies are warranted to further characterize the compounds responsible for the antioxidant properties of the examined extracts. Full article
Open AccessArticle Azolyacetones as Precursors to Indoles and Naphthofurans Facilitated by Microwave Irradiation with Simultaneous Cooling
Molecules 2009, 14(8), 2976-2984; doi:10.3390/molecules14082976
Received: 8 July 2009 / Revised: 30 July 2009 / Accepted: 5 August 2009 / Published: 11 August 2009
Cited by 5 | PDF Full-text (129 KB) | HTML Full-text | XML Full-text | Correction | Supplementary Files
Abstract
Phthalimide reacted with phenacyl bromide under microwave irradiation to yield phenacyl isoindolidene-1,3-dione (3b), while 3a reacted with phenylhydrazine to yield the phenylhydrazone 4 that was readily converted into indoylphthalimide 8. Similarly N-benzotriazolylacetone (6a) reacted with phenyl hydrazine to yield the phenylhydrazone [...] Read more.
Phthalimide reacted with phenacyl bromide under microwave irradiation to yield phenacyl isoindolidene-1,3-dione (3b), while 3a reacted with phenylhydrazine to yield the phenylhydrazone 4 that was readily converted into indoylphthalimide 8. Similarly N-benzotriazolylacetone (6a) reacted with phenyl hydrazine to yield the phenylhydrazone 7a that was converted into indoylbenzotriazole 9. Treatment of 8 with hydrazine hydrate afforded a mixture of phthalhydrazide 10 and 3-amino-2-methylindole (11). Reacting enaminone 13 with naphthoquinone (14) afforded the aryl naphthofuran 17. The possibility of the formation of the aldehyde 18 was excluded based on HMQC, which revealed that the carbonyl carbon is not linked to any hydrogen. Full article
Figures

Open AccessArticle Synthesis and Theoretical Study of Molecularly Imprinted Nanospheres for Recognition of Tocopherols
Molecules 2009, 14(8), 2985-3002; doi:10.3390/molecules14082985
Received: 13 June 2009 / Revised: 5 August 2009 / Accepted: 11 August 2009 / Published: 12 August 2009
Cited by 29 | PDF Full-text (737 KB) | HTML Full-text | XML Full-text
Abstract
Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In [...] Read more.
Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to tocopherol (vitamin E) and its derivative, tocopherol acetate. Binding of the imprinted polymers to the template was found to be two times greater than that of the control, non-imprinted polymers, when using only 10 mg of polymers. Optimization of the rebinding solvent indicated that ethanol-water at a molar ratio of 6:4 (v/v) was the best solvent system as it enhanced the rebinding performance of the imprinted polymers toward both tocopherol and tocopherol acetate with a binding capacity of approximately 2 mg/g of polymer. Furthermore, imprinted nanospheres against tocopherol was successfully prepared by precipitation polymerization with ethanol-water at a molar ratio of 8:2 (v/v) as the optimal rebinding solvent. Computer simulation was also performed to provide mechanistic insights on the binding mode of template-monomer complexes. Such polymers show high potential for industrial and medical applications, particularly for selective separation of tocopherol and derivatives. Full article
Figures

Open AccessArticle Structural Characterization of Calcium Alginate Matrices by Means of Mechanical and Release Tests
Molecules 2009, 14(8), 3003-3017; doi:10.3390/molecules14083003
Received: 25 June 2009 / Revised: 4 August 2009 / Accepted: 10 August 2009 / Published: 12 August 2009
Cited by 9 | PDF Full-text (234 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we have concentrated on the characterization of calcium alginate hydrogels loaded with a model drug (myoglobin) by means of a mechanical approach; in addition, release tests of myoglobin from alginate hydrogels were performed. At a fixed temperature, relaxation tests [...] Read more.
In this paper we have concentrated on the characterization of calcium alginate hydrogels loaded with a model drug (myoglobin) by means of a mechanical approach; in addition, release tests of myoglobin from alginate hydrogels were performed. At a fixed temperature, relaxation tests (mechanical study) were carried out on matrices constituted by different polymer concentrations. The interpretation of the relaxation behavior of the different matrices was conducted using the generalized Maxwell model; as a result of this investigation it was possible to conclude that for polymer concentrations greater than 0.5 g/ 100 mL the matrices behaved as solid materials. In addition, it was observed that the mechanical properties of the matrices increased with polymer concentration. With regard to the release tests, the diffusion coefficient of myoglobin in the matrix in relation to polymer concentrations was determined. The mechanical and release data where then analyzed by Flory’s theory and by a modified free-volume theory, respectively, to estimate the network mesh size ξ. The comparison between the mesh sizes obtained by the two approaches showed a satisfactory agreement for polymer concentrations greater than 0.5 g/100 mL. It should be noted that the approach proposed here to determine the polymeric network meshes is absolutely general and can be advantageously applied to the characterization of other similar polymeric systems. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Figures

Open AccessArticle Coupling Reactions of α-Bromocarboxylate with Non-Aromatic N-Heterocycles
Molecules 2009, 14(8), 3019-3029; doi:10.3390/molecules14083019
Received: 20 July 2009 / Revised: 30 July 2009 / Accepted: 12 August 2009 / Published: 13 August 2009
Cited by 3 | PDF Full-text (293 KB) | HTML Full-text | XML Full-text
Abstract
The conditions for the C-N bond forming reaction (C-N coupling reaction) between α-bromocarboxylate and nitrogen-containing non-aromatic heterocyclic rings under heterogeneous copper(I) oxide catalysis are investigated in this paper. All the generated compounds were fully characterized by IR, NMR and MS spectroscopy. Ab [...] Read more.
The conditions for the C-N bond forming reaction (C-N coupling reaction) between α-bromocarboxylate and nitrogen-containing non-aromatic heterocyclic rings under heterogeneous copper(I) oxide catalysis are investigated in this paper. All the generated compounds were fully characterized by IR, NMR and MS spectroscopy. Ab initio/DFT calculations of partial charges on nitrogen atoms in all the discussed heterocycles and on C(2) of carboxylate under applied conditions were predicted. These in silico results correlate relatively with the experimental observations. Full article
(This article belongs to the Special Issue Heck Coupling)
Open AccessArticle Asymmetric Friedel-Crafts Alkylation of Indole with Chalcones Catalyzed by Chiral Phosphoric Acids
Molecules 2009, 14(8), 3030-3036; doi:10.3390/molecules14083030
Received: 22 July 2009 / Revised: 6 August 2009 / Accepted: 10 August 2009 / Published: 13 August 2009
Cited by 17 | PDF Full-text (292 KB) | HTML Full-text | XML Full-text
Abstract
The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoric acid. Furthermore, the alkylation products can [...] Read more.
The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoric acid. Furthermore, the alkylation products can be obtained in much higher e.e.s after one only crystallization. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
Figures

Open AccessArticle Evolution of the Yields and Composition of Essential Oil from Portuguese Myrtle (Myrtus comunis L.) through the Vegetative Cycle
Molecules 2009, 14(8), 3094-3105; doi:10.3390/molecules14083094
Received: 28 July 2009 / Revised: 13 August 2009 / Accepted: 18 August 2009 / Published: 20 August 2009
Cited by 25 | PDF Full-text (230 KB) | HTML Full-text | XML Full-text
Abstract
The chemical composition of the essential oil of Portuguese myrtle was determined at different developmental stages of the plant: pre-flowering, flowering, unripe and ripe berries. The oil was extracted separately by Clevenger distillation from leaves, branches and berries. The yields vary from [...] Read more.
The chemical composition of the essential oil of Portuguese myrtle was determined at different developmental stages of the plant: pre-flowering, flowering, unripe and ripe berries. The oil was extracted separately by Clevenger distillation from leaves, branches and berries. The yields vary from 0.33% to 0.74% for leaves, 0.02% to 0.19% for branches, and 0.11% to 0.23% for berries. The highest yields were obtained for the leaves in October, and for the berries in September; branches show similar values in the months of June, July and September, and the samples collected in May and October produced very little amount of oil. Altogether, September seems to be the month with the best yields for the three parts of the plant. The essential oils were analyzed by GC and GC/MS, and a total of thirty five components were identified. The major components were limonene+1,8-cineole [25.9% (berries)–39.5% (leaves)], myrtenyl acetate [6.6% (berries)–24.8% (leaves)], α-pinene [9.7% (berries)–21.5% (leaves)], and linalool [6.2% (leaves)–36.5% (berries)]. Portuguese myrtle belongs to the group of myrtles which are characterized by the presence of myrtenyl acetate as one of the major components. Full article
Open AccessArticle Production of β-Maltooligosaccharides of α- and δ-Tocopherols by Klebsiella pneumoniae and Cyclodextrin Glucanotransferase as Anti-Allergic Agents
Molecules 2009, 14(8), 3106-3114; doi:10.3390/molecules14083106
Received: 14 July 2009 / Revised: 19 August 2009 / Accepted: 20 August 2009 / Published: 20 August 2009
Cited by 7 | PDF Full-text (139 KB) | HTML Full-text | XML Full-text
Abstract
The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside [...] Read more.
The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside (35%). On the other hand, δ-tocopheryl β-glucoside was converted into the corresponding β-maltoside (45%) and β-maltotrioside (29%) by CGTase. The β-glucoside of α-tocopherol, and β-glucoside and β-maltoside of δ-tocopherol showed inhibitory effects on IgE antibody production and on histamine release from rat peritoneal mast cells. Full article
(This article belongs to the Special Issue Vitamins)

Review

Jump to: Research, Other

Open AccessReview Nano and Microtechnologies for the Delivery of Oligonucleotides with Gene Silencing Properties
Molecules 2009, 14(8), 2801-2823; doi:10.3390/molecules14082801
Received: 30 June 2009 / Revised: 22 July 2009 / Accepted: 27 July 2009 / Published: 29 July 2009
Cited by 29 | PDF Full-text (538 KB)
Abstract
Oligonucleotides (ONs) are synthetic fragments of nucleic acid designed to modulate the expression of target proteins. DNA-based ONs (antisense, antigene, aptamer or decoy) and more recently a new class of RNA-based ONs, the small interfering RNAs (siRNAs), have gained great attention for [...] Read more.
Oligonucleotides (ONs) are synthetic fragments of nucleic acid designed to modulate the expression of target proteins. DNA-based ONs (antisense, antigene, aptamer or decoy) and more recently a new class of RNA-based ONs, the small interfering RNAs (siRNAs), have gained great attention for the treatment of different disease states, such as viral infections, inflammation, diabetes, and cancer. However, the development of therapeutic strategies based on ONs is hampered by their low bioavailability, poor intracellular uptake and rapid degradation in biological fluids. The use of a non-viral carrier can be a powerful tool to overcome these drawbacks. Lipid or polymer-based nanotechnologies can improve biological stability and cellular uptake of ONs, with possibility of tissue and/or cellular targeting. The use of polymeric devices can also produce a prolonged release of the ON, thus reducing the need of frequent administrations. This review summarizes advantages and issues related to the main non-viral vectors used for ON delivery. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Open AccessReview Recent Advances in the Discovery of Haem-Targeting Drugs for Malaria and Schistosomiasis
Molecules 2009, 14(8), 2868-2887; doi:10.3390/molecules14082868
Received: 30 June 2009 / Revised: 20 July 2009 / Accepted: 22 July 2009 / Published: 4 August 2009
Cited by 27 | PDF Full-text (824 KB) | HTML Full-text | XML Full-text
Abstract
Haem is believed to be the target of some of the historically most important antimalarial drugs, most notably chloroquine. This target is almost ideal as haem is host-derived and the process targeted, haemozoin formation, is a physico-chemical process with no equivalent in [...] Read more.
Haem is believed to be the target of some of the historically most important antimalarial drugs, most notably chloroquine. This target is almost ideal as haem is host-derived and the process targeted, haemozoin formation, is a physico-chemical process with no equivalent in the host. The result is that the target remains viable despite resistance to current drugs, which arises from mutations in parasite membrane transport proteins. Recent advances in high-throughput screening methods, together with a better understanding of the interaction of existing drugs with this target, have created new prospects for discovering novel haem-targeting chemotypes and for target-based structural design of new drugs. Finally, the discovery that Schistosoma mansoni also produces haemozoin suggests that new drugs of this type may be chemotherapeutic not only for malaria, but also for schistosomiasis. These recent developments in the literature are reviewed. Full article
(This article belongs to the Special Issue Neglected Diseases: Medicinal Chemistry and Natural Product Chemistry)
Figures

Open AccessReview Ionic Liquids as Advanced Lubricant Fluids
Molecules 2009, 14(8), 2888-2908; doi:10.3390/molecules14082888
Received: 17 July 2009 / Revised: 30 July 2009 / Accepted: 3 August 2009 / Published: 4 August 2009
Cited by 238 | PDF Full-text (450 KB) | HTML Full-text | XML Full-text
Abstract
Ionic liquids (ILs) are finding technological applications as chemical reaction media and engineering fluids. Some emerging fields are those of lubrication, surface engineering and nanotechnology. ILs are thermally stable, non-flammable highly polar fluids with negligible volatility, these characteristics make them ideal candidates [...] Read more.
Ionic liquids (ILs) are finding technological applications as chemical reaction media and engineering fluids. Some emerging fields are those of lubrication, surface engineering and nanotechnology. ILs are thermally stable, non-flammable highly polar fluids with negligible volatility, these characteristics make them ideal candidates for new lubricants under severe conditions, were conventional oils and greases or solid lubricants fail. Such conditions include ultra-high vacuum and extreme temperatures. Other very promising areas which depend on the interaction between IL molecules and material surfaces are the use of ILs in the lubrication of microelectromechanic and nanoelectromechanic systems (MEMS and NEMS), the friction and wear reduction of reactive light alloys and the modification of nanophases. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessReview Chemical and Biological Characterization of Oleanane Triterpenoids from Soy
Molecules 2009, 14(8), 2959-2975; doi:10.3390/molecules14082959
Received: 24 June 2009 / Revised: 21 July 2009 / Accepted: 6 August 2009 / Published: 10 August 2009
Cited by 28 | PDF Full-text (564 KB) | HTML Full-text | XML Full-text
Abstract
Soyasaponins are a group of complex and structural diverse oleanane triterpenoids found in soy (Glycine max) and other legumes. They are primarily classified into two main groups − group A and B − based on the attachment of sugar moieties [...] Read more.
Soyasaponins are a group of complex and structural diverse oleanane triterpenoids found in soy (Glycine max) and other legumes. They are primarily classified into two main groups − group A and B − based on the attachment of sugar moieties at positions C-3 and C-22 of the ring structures. Group A soyasaponins are bidesmosidic, while group B soyasaponins are monodesmosidic. Group B soyasaponins are further classified into two subcategories known as 2,3-dihydro-2,5-dihydroxy-6 -methyl-4H-pyran-4-one (DDMP) and non-DDMP conjugated molecules. The preparation and purification of soyasaponin molecules is complicated by the presence of bioactive soy isoflavones, which often overlap with soyasaponin in polarity and must removed from extracts before biological assessment. Soyasaponin extracts, aglycones of group A and B and individual group B soyasaponins such as soyasaponin I have been reported to posses specific bioactive properties, such as in vitro anti-cancer properties by modulating the cell cycle and inducing apoptosis. The isolation, chemical characterization and detection strategies by HPLC and HPLC-MS are reviewed, along with the reported bioactive effects of soyasaponin extracts and individual molecules in cultured cancer cell experiments. Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
Open AccessReview Plant-Derived Antimalarial Agents: New Leads and Efficient Phytomedicines. Part II. Non-Alkaloidal Natural Products
Molecules 2009, 14(8), 3037-3072; doi:10.3390/molecules14083037
Received: 9 July 2009 / Revised: 7 August 2009 / Accepted: 13 August 2009 / Published: 13 August 2009
Cited by 78 | PDF Full-text (520 KB) | HTML Full-text | XML Full-text
Abstract
Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an [...] Read more.
Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Natural products have played a dominant role in the discovery of leads for the development of drugs to treat human diseases, and this fact anticipates that new antimalarial leads may certainly emerge from tropical plant sources. This present review covers most of the recently-published non-alkaloidal natural compounds from plants with antiplasmodial and antimalarial properties, belonging to the classes of terpenes, limonoids, flavonoids, chromones, xanthones, anthraquinones, miscellaneous and related compounds, besides the majority of papers describing antiplasmodial crude extracts published in the last five years not reviewed before. In addition, some perspectives and remarks on the development of new drugs and phytomedicines for malaria are succinctly discussed. Full article
(This article belongs to the Special Issue Neglected Diseases: Medicinal Chemistry and Natural Product Chemistry)
Figures

Open AccessReview Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System
Molecules 2009, 14(8), 3073-3093; doi:10.3390/molecules14083073
Received: 6 July 2009 / Revised: 31 July 2009 / Accepted: 10 August 2009 / Published: 14 August 2009
Cited by 17 | PDF Full-text (532 KB) | HTML Full-text | XML Full-text
Abstract
A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon [...] Read more.
A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization. Full article
(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)

Other

Jump to: Research, Review

Open AccessCorrection Correction: Meulenberg, E. P. Phenolics: Occurrence and Immunochemical Detection in Environment and Food. Molecules 2009, 14, 439-473
Molecules 2009, 14(8), 3018; doi:10.3390/molecules140803018
Received: 3 August 2009 / Published: 13 August 2009
PDF Full-text (15 KB) | HTML Full-text | XML Full-text
Abstract In the original published version of this paper [1], there are two repeated refs. 134 in the reference list.[...] Full article

Journal Contact

MDPI AG
Molecules Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
molecules@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Molecules
Back to Top