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Molecules, Volume 14, Issue 8 (August 2009) – 33 articles , Pages 2684-3114

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417 KiB  
Article
Physical Carboxymethylscleroglucan/Calcium Ion Hydrogels as Modified Drug Delivery Systems in Topical Formulations
by Federica Corrente, Pietro Matricardi, Patrizia Paolicelli, Beatrice Tita, Federica Vitali and Maria Antonietta Casadei
Molecules 2009, 14(8), 2684-2698; https://doi.org/10.3390/molecules14082684 - 24 Jul 2009
Cited by 17 | Viewed by 11621
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 as [...] 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)
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536 KiB  
Article
Influence of Different Polymer Types on the Overall Release Mechanism in Hydrophilic Matrix Tablets
by Anna Körner, Lennart Piculell, Frida Iselau, Bengt Wittgren and Anette Larsson
Molecules 2009, 14(8), 2699-2716; https://doi.org/10.3390/molecules14082699 - 24 Jul 2009
Cited by 33 | Viewed by 13115
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 release [...] 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)
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430 KiB  
Article
Headspace, Volatile and Semi-Volatile Organic Compounds Diversity and Radical Scavenging Activity of Ultrasonic Solvent Extracts from Amorpha fruticosa Honey Samples
by Igor Jerković, Zvonimir Marijanović, Janja Kezić and Mirko Gugić
Molecules 2009, 14(8), 2717-2728; https://doi.org/10.3390/molecules14082717 - 27 Jul 2009
Cited by 44 | Viewed by 13129
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 aroma. [...] 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)
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212 KiB  
Article
Coumarins from Angelica Lucida L. - Antibacterial Activities
by Jaroslaw Widelski, Milena Popova, Konstantia Graikou, Kazimierz Glowniak and Ioanna Chinou
Molecules 2009, 14(8), 2729-2734; https://doi.org/10.3390/molecules14082729 - 27 Jul 2009
Cited by 61 | Viewed by 14404
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 and [...] 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)
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127 KiB  
Article
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)
by Laura De Martino, Vincenzo De Feo, Carmen Formisano, Enrico Mignola and Felice Senatore
Molecules 2009, 14(8), 2735-2746; https://doi.org/10.3390/molecules14082735 - 27 Jul 2009
Cited by 143 | Viewed by 18065
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 of [...] 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
308 KiB  
Article
Wet Aerobic Oxidation of Lignin into Aromatic Aldehydes Catalysed by a Perovskite-type Oxide: LaFe1-xCuxO3 (x=0, 0.1, 0.2)
by Junhua Zhang, Haibo Deng and Lu Lin
Molecules 2009, 14(8), 2747-2757; https://doi.org/10.3390/molecules14082747 - 27 Jul 2009
Cited by 94 | Viewed by 13597
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 each [...] 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)
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182 KiB  
Article
New Synthesis and Antiparasitic Activity of Model 5-Aryl-1-methyl-4-nitroimidazoles
by Haythem A. Saadeh, Ibrahim M. Mosleh and Mustafa M. El-Abadelah
Molecules 2009, 14(8), 2758-2767; https://doi.org/10.3390/molecules14082758 - 27 Jul 2009
Cited by 17 | Viewed by 11203
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 by [...] 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
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502 KiB  
Article
Synthesis of N-Substituted 5-Iodouracils as Antimicrobial and Anticancer Agents
by Supaluk Prachayasittikul, Nirun Sornsongkhram, Ratchanok Pingaew, Apilak Worachartcheewan, Somsak Ruchirawat and Virapong Prachayasittikul
Molecules 2009, 14(8), 2768-2779; https://doi.org/10.3390/molecules14082768 - 27 Jul 2009
Cited by 28 | Viewed by 10925
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, CH2 [...] 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
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390 KiB  
Article
Synthesis and Olfactory Evaluation of Bulky Moiety-Modified Analogues to the Sandalwood Odorant Polysantol®
by Laura Chapado, Pablo J. Linares-Palomino, Concepción Badía, Sofía Salido, Manuel Nogueras, Adolfo Sánchez and Joaquín Altarejos
Molecules 2009, 14(8), 2780-2800; https://doi.org/10.3390/molecules14082780 - 28 Jul 2009
Cited by 4 | Viewed by 13076
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 and [...] 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
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257 KiB  
Communication
Enantiopure Derivatives of Aza-Baylis-Hillman Adducts by Subsequent SN′-SN′ Reactions of Acylcarbamates Bearing a Chiral Auxiliary
by Gianluca Martelli, Eleonora Marcucci, Mario Orena and Samuele Rinaldi
Molecules 2009, 14(8), 2824-2835; https://doi.org/10.3390/molecules14082824 - 30 Jul 2009
Cited by 3 | Viewed by 8981
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)
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211 KiB  
Article
Efficient Microwave Assisted Syntheses of 2,5-Diketopiperazines in Aqueous Media
by Lemuel Pérez-Picaso, Jaime Escalante, Horacio F. Olivo and María Yolanda Rios
Molecules 2009, 14(8), 2836-2849; https://doi.org/10.3390/molecules14082836 - 31 Jul 2009
Cited by 43 | Viewed by 11982
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 group [...] 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)
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381 KiB  
Article
(+)-N-(2-Hydroxypropyl)lindcarpine: A New Cytotoxic Aporphine Isolated from Actinodaphne pruinosa Nees
by Tiah Rachmatiah, Mat Ropi Mukhtar, Mohd Azlan Nafiah, Muhammad Hanafi, Soleh Kosela, Hiroshi Morita, Marc Litaudon, Khalijah Awang, Hanita Omar and A. Hamid A. Hadi
Molecules 2009, 14(8), 2850-2856; https://doi.org/10.3390/molecules14082850 - 31 Jul 2009
Cited by 17 | Viewed by 11160
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 with [...] 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)
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63 KiB  
Article
Quinones as Key Intermediates in Natural Products Synthesis. Syntheses of Bioactive Xanthones from Hypericum perforatum
by George A. Kraus and John Mengwasser
Molecules 2009, 14(8), 2857-2861; https://doi.org/10.3390/molecules14082857 - 03 Aug 2009
Cited by 15 | Viewed by 11037
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
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117 KiB  
Article
A New Sesquiterpene from the Fruits of Daucus carota L.
by Hong-Wei Fu, Lin Zhang, Tao Yi and Jing-Kui Tian
Molecules 2009, 14(8), 2862-2867; https://doi.org/10.3390/molecules14082862 - 03 Aug 2009
Cited by 10 | Viewed by 10938 | Correction
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 1 [...] 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
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118 KiB  
Article
Chemical Composition of the Essential Oils of Cyperus rotundus L. from South Africa
by Oladipupo A. Lawal and Adebola O. Oyedeji
Molecules 2009, 14(8), 2909-2917; https://doi.org/10.3390/molecules14082909 - 06 Aug 2009
Cited by 111 | Viewed by 18239
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 were [...] 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
233 KiB  
Article
Cross-Cyclotrimerization with Two Nitriles as a Synthetic Pathway to Unsymmetrically 3,3’-Disubstituted bis(Tetrahydroisoquinolines)
by Aneta Kadlčíková and Martin Kotora
Molecules 2009, 14(8), 2918-2926; https://doi.org/10.3390/molecules14082918 - 10 Aug 2009
Cited by 18 | Viewed by 10054
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)
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267 KiB  
Communication
Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS
by Zhi Zeng, Han Zhang, Tao Zhang, Shigeru Tamogami and Jie Yu Chen
Molecules 2009, 14(8), 2927-2934; https://doi.org/10.3390/molecules14082927 - 10 Aug 2009
Cited by 6 | Viewed by 12395
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 rice [...] 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
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271 KiB  
Article
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
by Shuang-Fei Cai, Li-Sheng Wang and Chuan-Lei Fan
Molecules 2009, 14(8), 2935-2946; https://doi.org/10.3390/molecules14082935 - 10 Aug 2009
Cited by 29 | Viewed by 13098
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 and [...] 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 Collection Ionic Liquids)
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225 KiB  
Article
Antioxidant Activity of Some Plant Extracts Towards Xanthine Oxidase, Lipoxygenase and Tyrosinase
by Chin-Hui Chen, Hsiu-Chen Chan, Yi-Tsu Chu, Hsin-Yi Ho, Pi-Yu Chen, Tzong-Huei Lee and Ching-Kuo Lee
Molecules 2009, 14(8), 2947-2958; https://doi.org/10.3390/molecules14082947 - 10 Aug 2009
Cited by 91 | Viewed by 17392
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. This [...] 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
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129 KiB  
Article
Azolyacetones as Precursors to Indoles and Naphthofurans Facilitated by Microwave Irradiation with Simultaneous Cooling
by Saleh Mohammed Al-Mousawi and Morsy Ahmed El-Apasery
Molecules 2009, 14(8), 2976-2984; https://doi.org/10.3390/molecules14082976 - 11 Aug 2009
Cited by 8 | Viewed by 12605 | Correction
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 7a [...] 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
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737 KiB  
Article
Synthesis and Theoretical Study of Molecularly Imprinted Nanospheres for Recognition of Tocopherols
by Theeraphon Piacham, Chanin Nantasenamat, Thummaruk Suksrichavalit, Charoenchai Puttipanyalears, Tippawan Pissawong, Supanee Maneewas, Chartchalerm Isarankura-Na-Ayudhya and Virapong Prachayasittikul
Molecules 2009, 14(8), 2985-3002; https://doi.org/10.3390/molecules14082985 - 12 Aug 2009
Cited by 41 | Viewed by 14885
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 this [...] 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
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234 KiB  
Article
Structural Characterization of Calcium Alginate Matrices by Means of Mechanical and Release Tests
by Mario Grassi, Chiara Sandolo, Danilo Perin, Tommasina Coviello, Romano Lapasin and Gabriele Grassi
Molecules 2009, 14(8), 3003-3017; https://doi.org/10.3390/molecules14083003 - 12 Aug 2009
Cited by 37 | Viewed by 17163
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 (mechanical [...] 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)
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293 KiB  
Article
Coupling Reactions of α-Bromocarboxylate with Non-Aromatic N-Heterocycles
by Katerina Brychtova, Barbora Slaba, Lukas Placek, Josef Jampilek, Ivan Raich and Jozef Csollei
Molecules 2009, 14(8), 3019-3029; https://doi.org/10.3390/molecules14083019 - 13 Aug 2009
Cited by 3 | Viewed by 10455
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 initio [...] 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)
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292 KiB  
Article
Asymmetric Friedel-Crafts Alkylation of Indole with Chalcones Catalyzed by Chiral Phosphoric Acids
by Arrigo Scettri, Rosaria Villano and Maria Rosaria Acocella
Molecules 2009, 14(8), 3030-3036; https://doi.org/10.3390/molecules14083030 - 13 Aug 2009
Cited by 26 | Viewed by 15826
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 be [...] 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)
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230 KiB  
Article
Evolution of the Yields and Composition of Essential Oil from Portuguese Myrtle (Myrtus comunis L.) through the Vegetative Cycle
by Paula C. Pereira, Maria-João Cebola and M. Gabriela Bernardo-Gil
Molecules 2009, 14(8), 3094-3105; https://doi.org/10.3390/molecules14083094 - 20 Aug 2009
Cited by 48 | Viewed by 12023
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 0.33% [...] 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
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139 KiB  
Article
Production of β-Maltooligosaccharides of α- and δ-Tocopherols by Klebsiella pneumoniae and Cyclodextrin Glucanotransferase as Anti-Allergic Agents
by Kei Shimoda, Masaaki Akagi and Hiroki Hamada
Molecules 2009, 14(8), 3106-3114; https://doi.org/10.3390/molecules14083106 - 20 Aug 2009
Cited by 13 | Viewed by 9720
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 (35%). [...] 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)
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Review

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538 KiB  
Review
Nano and Microtechnologies for the Delivery of Oligonucleotides with Gene Silencing Properties
by Giuseppe De Rosa and Maria Immacolata La Rotonda
Molecules 2009, 14(8), 2801-2823; https://doi.org/10.3390/molecules14082801 - 29 Jul 2009
Cited by 37 | Viewed by 16481
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 the [...] 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)
824 KiB  
Review
Recent Advances in the Discovery of Haem-Targeting Drugs for Malaria and Schistosomiasis
by Katherine A. De Villiers and Timothy J. Egan
Molecules 2009, 14(8), 2868-2887; https://doi.org/10.3390/molecules14082868 - 04 Aug 2009
Cited by 47 | Viewed by 15571
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 the [...] 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)
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450 KiB  
Review
Ionic Liquids as Advanced Lubricant Fluids
by María-Dolores Bermúdez, Ana-Eva Jiménez, José Sanes and Francisco-José Carrión
Molecules 2009, 14(8), 2888-2908; https://doi.org/10.3390/molecules14082888 - 04 Aug 2009
Cited by 557 | Viewed by 24076
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 for [...] 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 Collection Ionic Liquids)
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564 KiB  
Review
Chemical and Biological Characterization of Oleanane Triterpenoids from Soy
by Wei Zhang and David G. Popovich
Molecules 2009, 14(8), 2959-2975; https://doi.org/10.3390/molecules14082959 - 10 Aug 2009
Cited by 68 | Viewed by 19294
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 at [...] 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 2013)
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520 KiB  
Review
Plant-Derived Antimalarial Agents: New Leads and Efficient Phytomedicines. Part II. Non-Alkaloidal Natural Products
by Ronan Batista, Ademir De Jesus Silva Júnior and Alaíde Braga De Oliveira
Molecules 2009, 14(8), 3037-3072; https://doi.org/10.3390/molecules14083037 - 13 Aug 2009
Cited by 223 | Viewed by 27200
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 urgent [...] 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)
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532 KiB  
Review
Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System
by Yuka Kawashita and Masahiko Hayashi
Molecules 2009, 14(8), 3073-3093; https://doi.org/10.3390/molecules14083073 - 14 Aug 2009
Cited by 40 | Viewed by 14944
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 in [...] 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)
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Other

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15 KiB  
Correction
Correction: Meulenberg, E. P. Phenolics: Occurrence and Immunochemical Detection in Environment and Food. Molecules 2009, 14, 439-473
by Eline P. Meulenberg
Molecules 2009, 14(8), 3018; https://doi.org/10.3390/molecules140803018 - 13 Aug 2009
Viewed by 7186
Abstract
In the original published version of this paper [1], there are two repeated refs. 134 in the reference list.[...] Full article
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