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Molecules, Volume 15, Issue 2 (February 2010), Pages 606-1096

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Open AccessArticle Caloxanthones O and P: Two New Prenylated Xanthones from Calophyllum inophyllum
Molecules 2010, 15(2), 606-612; doi:10.3390/molecules15020606
Received: 30 November 2009 / Revised: 4 January 2010 / Accepted: 8 January 2010 / Published: 27 January 2010
Cited by 3 | PDF Full-text (238 KB)
Abstract
Chemical investigation of the EtOH extract of the twigs of Calophyllum inophyllum collected in Hainan Province of China resulted in the isolation of two new prenylated xanthones, caloxanthone O (1) and caloxanthone P (2). Their structures were elucidated by
[...] Read more.
Chemical investigation of the EtOH extract of the twigs of Calophyllum inophyllum collected in Hainan Province of China resulted in the isolation of two new prenylated xanthones, caloxanthone O (1) and caloxanthone P (2). Their structures were elucidated by a study of their physical and spectral data. Compound 1 exhibited cytotoxicity against human gastric cancer cell line (SGC-7901),with an IC50 value of 22.4 μg mL-1. Full article
Open AccessCommunication A New Furostanol Glycoside from Tribulus terrestris
Molecules 2010, 15(2), 613-618; doi:10.3390/molecules15020613
Received: 10 November 2009 / Revised: 13 January 2010 / Accepted: 18 January 2010 / Published: 27 January 2010
Cited by 2 | PDF Full-text (239 KB)
Abstract
Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-β-D-glucopyranosyl-(25S)-5α-furostane-20(22)-en-12-one-3β, 26-diol-3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-galactopyranoside
[...] Read more.
Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-β-D-glucopyranosyl-(25S)-5α-furostane-20(22)-en-12-one-3β, 26-diol-3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations. Full article
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Open AccessArticle Detection of HIV cDNA Point Mutations with Rolling-Circle Amplification Arrays
Molecules 2010, 15(2), 619-626; doi:10.3390/molecules15020619
Received: 2 November 2009 / Revised: 28 December 2009 / Accepted: 18 January 2010 / Published: 27 January 2010
Cited by 2 | PDF Full-text (244 KB)
Abstract
In this paper we describe an isothermal rolling-circle amplification (RCA) protocol to detect gene point mutations on chips. The method is based on an allele-specific oligonucleotide circularization mediated by a special DNA ligase. The probe is circularized when perfect complementary sequences between the
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In this paper we describe an isothermal rolling-circle amplification (RCA) protocol to detect gene point mutations on chips. The method is based on an allele-specific oligonucleotide circularization mediated by a special DNA ligase. The probe is circularized when perfect complementary sequences between the probe oligonucleotide and HIV cDNA gene. Mismatches around the ligation site can prevent probe circularization. The circularized probe (C-probe) can be amplified by rolling circle amplification to generate multimeric singlestranded DNA (ssDNA) under isothermal conditions. There are four sequence regions to bind respectively with fluorescent probe, RCA primer, solid probe and HIV cDNA template in the C-probe which we designed. These ssDNA products are hybridized with fluorescent probes and solid probes which are immobilized on a glass slide composing a regular microarray pattern. The fluorescence signals can be monitored by a scanner in the presence of HIV cDNA templates, whereas the probes cannot be circularized and signal of fluorescence cannot be found. The RCA array has capability of high-throughput detection of the point mutation and the single-nucleotide polymorphism (SNP).The development of C-probe-based technologies offers a promising prospect for situ detection, microarray, molecular diagnosis, single nucleotide polymorphism, and whole genome amplification. Full article
Open AccessArticle Essential Oil Composition of Stems and Fruits of Caralluma europaea N.E.Br. (Apocynaceae)
Molecules 2010, 15(2), 627-638; doi:10.3390/molecules15020627
Received: 30 December 2009 / Revised: 19 January 2010 / Accepted: 22 January 2010 / Published: 27 January 2010
Cited by 23 | PDF Full-text (422 KB)
Abstract
The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and
[...] Read more.
The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed. Full article
Open AccessArticle New Neolignans and a Phenylpropanoid Glycoside from Twigs of Miliusa mollis
Molecules 2010, 15(2), 639-648; doi:10.3390/molecules15020639
Received: 8 December 2009 / Revised: 20 January 2010 / Accepted: 22 January 2010 / Published: 28 January 2010
Cited by 10 | PDF Full-text (354 KB)
Abstract From the twigs of Miliusa mollis Pierre, three new compounds including (2S,3S)-2,3-dihydro-2-(4-methoxyphenyl)-3-methyl-5-[1(E)-propenyl]benzofuran, (7S,8S)- threo8'-4-methoxyneolignan and tyrosol-1-O-β-xylopyranosyl-(1→6)-O-β-gluco-pyranoside were isolated, along with seven known compounds. Their structures were elucidated through analysis of their spectroscopic data. Full article
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Open AccessArticle Palladium-Catalyzed Heck Coupling Reaction of Aryl Bromides in Aqueous Media Using Tetrahydropyrimidinium Salts as Carbene Ligands
Molecules 2010, 15(2), 649-659; doi:10.3390/molecules15020649
Received: 16 December 2009 / Revised: 1 January 2010 / Accepted: 12 January 2010 / Published: 28 January 2010
Cited by 12 | PDF Full-text (214 KB)
Abstract
An efficient and stereoselective catalytic system for the Heck cross coupling reaction using novel 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (1, LHX) and Pd(OAc)2 loading has been reported. The palladium complexes derived from the salts 1a-f prepared in situ exhibit good catalytic activity
[...] Read more.
An efficient and stereoselective catalytic system for the Heck cross coupling reaction using novel 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (1, LHX) and Pd(OAc)2 loading has been reported. The palladium complexes derived from the salts 1a-f prepared in situ exhibit good catalytic activity in the Heck coupling reaction of aryl bromides under mild conditions. Full article
(This article belongs to the Special Issue Heck Coupling)
Open AccessArticle Antileishmanial, Antimicrobial and Antifungal Activities of Some New Aryl Azomethines
Molecules 2010, 15(2), 660-671; doi:10.3390/molecules15020660
Received: 5 December 2009 / Revised: 28 December 2009 / Accepted: 8 January 2010 / Published: 28 January 2010
Cited by 22 | PDF Full-text (228 KB)
Abstract
A series of eighteen azomethines has been synthesized by the reaction of appropriate primary aromatic amines with aryl and/or heteroaryl carboxaldehydes. The synthesized azomethines have been evaluated for their in vitro antileishmanial, antibacterial and antifungal activities. The results revealed some antifungal activity of
[...] Read more.
A series of eighteen azomethines has been synthesized by the reaction of appropriate primary aromatic amines with aryl and/or heteroaryl carboxaldehydes. The synthesized azomethines have been evaluated for their in vitro antileishmanial, antibacterial and antifungal activities. The results revealed some antifungal activity of most of the synthesized compounds, whereas the antileishmaniasis activity results highlighted that all synthesized azomethines inhibited parasite growth and most of them showed highly potent action towards Leishmania major promastigotes. No remarkable bactericidal activities were observed. Full article
Open AccessCommunication A New Flavone C-Glycoside from Clematis rehderiana
Molecules 2010, 15(2), 672-679; doi:10.3390/molecules15020672
Received: 24 December 2009 / Revised: 28 January 2010 / Accepted: 29 January 2010 / Published: 29 January 2010
Cited by 11 | PDF Full-text (228 KB)
Abstract
A new flavone C-glycoside, isovitexin 6″-O-E-p-coumarate (1) and two known flavonoid glycosides—quercetin 3-O-β-D-glucuronopyranoside (2) and isoorientin (3)—were isolated from an ethanol extract of aerial parts of Clematis rehderiana. Their structures were determined by
[...] Read more.
A new flavone C-glycoside, isovitexin 6″-O-E-p-coumarate (1) and two known flavonoid glycosides—quercetin 3-O-β-D-glucuronopyranoside (2) and isoorientin (3)—were isolated from an ethanol extract of aerial parts of Clematis rehderiana. Their structures were determined by spectroscopic methods. The antioxidant effects of the two flavone C-glycosides were evaluated by both the MTT and DPPH assays. Compound 1 showed potent activities against H2O2-induced impairment in PC12 cells within the concentration range tested, whereas compound 3 scavenged DPPH radical strongly, with an IC50 value of 13.5 μM. Full article
Open AccessArticle A Comparative Identification of Ochratoxin A in Longan Fruit Pulp by High Performance Liquid Chromatography-Fluorescence Detection and Electron Spray Ionization-Mass Spectrometry
Molecules 2010, 15(2), 680-688; doi:10.3390/molecules15020680
Received: 22 December 2009 / Revised: 9 January 2010 / Accepted: 29 January 2010 / Published: 29 January 2010
Cited by 5 | PDF Full-text (519 KB)
Abstract
Harvested longan (Dimocarpus longan Lour.) fruit are susceptible to decay caused by both bacterial and fungal infections. Ochratoxin A (OTA) is a kind of mycotoxin produced by a number of fungi. In this study, OTA was extracted from longan fruit pulp by
[...] Read more.
Harvested longan (Dimocarpus longan Lour.) fruit are susceptible to decay caused by both bacterial and fungal infections. Ochratoxin A (OTA) is a kind of mycotoxin produced by a number of fungi. In this study, OTA was extracted from longan fruit pulp by 80% methanol and then loaded on C-18 solid-phase extraction columns. The extract solution was then analyzed by high-performance liquid chromatography - fluorescence detection (HPLC-FD) and an electron spray ionization-mass spectrometry (ESI-MS), respectively. The HPLC-FD analysis showed that a compound similar to OTA might exist in longan fruit pulp, but further analysis by the ESI-MS method demonstrated that OTA was not present in the longan pulp, indicating that the presence of OTA in longan fruit pulp detected by the HPLC-FD analysis needed to be confirmed by the ESI-MS method. Full article
Open AccessArticle Chemical Analysis and Biological Activity of the Essential Oils of Two Endemic Soqotri Commiphora Species
Molecules 2010, 15(2), 689-698; doi:10.3390/molecules15020689
Received: 30 December 2009 / Revised: 25 January 2010 / Accepted: 28 January 2010 / Published: 1 February 2010
Cited by 15 | PDF Full-text (143 KB)
Abstract
The barks of two endemic Commiphora species namely, Commiphora ornifolia (Balf.f.) Gillett and Commiphora parvifolia Engl., were collected from Soqotra Island in Yemen and their essential oils were obtained by hydrodistillation. The chemical composition of both oils was investigated by GC and GC-MS.
[...] Read more.
The barks of two endemic Commiphora species namely, Commiphora ornifolia (Balf.f.) Gillett and Commiphora parvifolia Engl., were collected from Soqotra Island in Yemen and their essential oils were obtained by hydrodistillation. The chemical composition of both oils was investigated by GC and GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and one yeast species by using a broth micro-dilution assay for minimum inhibitory concentrations (MIC) and for their antioxidant activity by measuring the DPPH radical scavenging activity. A total of 45 constituents of C. ornifolia (85.6%) and 44 constituents of C. parvifolia (87.1%) were identified. The oil of C. ornifolia was characterized by a high content of oxygenated monoterpenes (56.3%), of which camphor (27.3%), α-fenchol (15.5%), fenchone (4.4%) and borneol (2.9%) were identified as the main components. High contents of oxygenated sesquiterpenes (36.1%) and aliphatic acids (22.8%) were found in C. parvifolia oil, in which caryophyllene oxide (14.2%), β-eudesmol (7.7%), bulnesol (5.7%), T-cadinol (3.7%) and hexadecanoic acid (18.4%) predominated. The results of the antimicrobial assay showed that both oils exhibited moderate to high antibacterial activity especially against Gram-positive bacteria. C. ornifolia oil was the most active. In addition, the DPPH-radical scavenging assay exhibited only weak antioxidant activities for both oils at the high concentration tested. Full article
Open AccessArticle Facile Synthesis and Preferred Conformation Analysis of Cyclododeceno[b]indene
Molecules 2010, 15(2), 699-708; doi:10.3390/molecules15020699
Received: 23 December 2009 / Revised: 21 January 2010 / Accepted: 25 January 2010 / Published: 1 February 2010
PDF Full-text (355 KB)
Abstract
Using methanesulfonic acid as a catalyst, a series of cyclododeceno[b]indene derivatives were synthesized by the cyclization of α-benzylcyclododecanones, which were prepared by the reactions of cyclododecanones with a variety of substituted benzyl chlorides or bromides using NaH as a base. Their structures were
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Using methanesulfonic acid as a catalyst, a series of cyclododeceno[b]indene derivatives were synthesized by the cyclization of α-benzylcyclododecanones, which were prepared by the reactions of cyclododecanones with a variety of substituted benzyl chlorides or bromides using NaH as a base. Their structures were confirmed by mp, IR spectra, 1H-NMR, 13C-NMR, MS, and x-ray diffraction. The preferred conformations were analyzed by crystal structure, 1H-NMR and quantum chemistry calculations, and compared with the x-ray diffraction structure of 2,3,5,6-bis(ortho-1,10-decylidene)dihydropyrazine. The results showed that the cyclododecene moiety adopted a preferred [1ene2333] conformation, and the substituted groups at aromatic ring had no significant influence on the conformation. Full article
Open AccessArticle Chemical Composition and Antigerminative Activity of the Essential Oils from Five Salvia Species
Molecules 2010, 15(2), 735-746; doi:10.3390/molecules15020735
Received: 9 January 2010 / Revised: 27 January 2010 / Accepted: 29 January 2010 / Published: 1 February 2010
Cited by 18 | PDF Full-text (178 KB)
Abstract
The chemical composition of the essential oils of Salvia africana L., Salvia elegans Vahl, Salvia greggii A. Gray, Salvia mellifera Green and Salvia munzii Epling, cultivated in Eboli (Salerno, Southern Italy), was studied by means of GC and GC-MS analyses. In all, 88
[...] Read more.
The chemical composition of the essential oils of Salvia africana L., Salvia elegans Vahl, Salvia greggii A. Gray, Salvia mellifera Green and Salvia munzii Epling, cultivated in Eboli (Salerno, Southern Italy), was studied by means of GC and GC-MS analyses. In all, 88 compounds were identified, 54 for S. africana, accounting for 95.4% of the total oil, 55 for S. elegans (92.9%), 50 for S. greggii (96.9%), 54 for S. mellifera (90.4%) and 47 for S. munzii (97.5%), respectively. In S. africana,the amount of monoterpenoids and sesquiterpenoids is very similar. For other species, the monoterpenoid percentage is greater than the amount of sesquiterpenoids. The oils of S. elegans, S. greggii and S. munzii were active inhibitors of germination and radical elongation of Raphanus sativus L. and Lepidium sativum L. Full article
Open AccessArticle Catalytic Performance of Ceria Nanorods in Liquid-Phase Oxidations of Hydrocarbons with tert-Butyl Hydroperoxide
Molecules 2010, 15(2), 747-765; doi:10.3390/molecules15020747
Received: 9 December 2009 / Revised: 28 January 2010 / Accepted: 29 January 2010 / Published: 2 February 2010
Cited by 18 | PDF Full-text (737 KB)
Abstract
The CeO2 nanorods (CeNR) promote the oxidation of ethylbenzene (PhEt) and cyclohexene with t-BuOOH, at temperatures as low as 55 ºC. For both substrates the saturated C-H bonds are preferentially activated over the unsaturated ones. The catalyst seems fairly stable towards leaching
[...] Read more.
The CeO2 nanorods (CeNR) promote the oxidation of ethylbenzene (PhEt) and cyclohexene with t-BuOOH, at temperatures as low as 55 ºC. For both substrates the saturated C-H bonds are preferentially activated over the unsaturated ones. The catalyst seems fairly stable towards leaching phenomena. The liquid-phase oxidation catalysis may be associated with the Ce3+/Ce4+ inter-conversion in the one-electron redox processes mediating the formation of tert-butyl-(per)oxy radicals. CeNR is very effective in H2O2 disproportionation. Pre-treatment of CeNR with H2O2 or t-BuOOH prior to the catalytic reaction enhances the reaction rate of PhEt with t-BuOOH in comparison to CeNR. Textural characterization and spectroscopic studies suggest that catalytic activation is associated to defect sites. Full article
(This article belongs to the Special Issue Nano-catalysts and Nano-technologies for Green Organic Synthesis)
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Open AccessArticle Synthesis and Crystal Structure of Novel Sulfone Derivatives Containing 1,2,4-Triazole Moieties
Molecules 2010, 15(2), 766-779; doi:10.3390/molecules15020766
Received: 5 November 2009 / Revised: 25 January 2010 / Accepted: 29 January 2010 / Published: 3 February 2010
Cited by 11 | PDF Full-text (450 KB)
Abstract
Some 3-(Substituted methylthio)-4-phenyl-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole derivatives were synthesized in six steps starting from easily accessible gallic acid. The resulting sulfides were then catalytically oxidized to the title sulfones with H2O2. The products were obtained in high yield under mild
[...] Read more.
Some 3-(Substituted methylthio)-4-phenyl-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole derivatives were synthesized in six steps starting from easily accessible gallic acid. The resulting sulfides were then catalytically oxidized to the title sulfones with H2O2. The products were obtained in high yield under mild conditions and practically devoid of any by-products. The structures were confirmed by elemental analysis, IR, 1H- and 13C-NMR spectral data. Furthermore, a detailed X-ray crystallography structural analysis of model triazole 7g was carried out. Full article
Open AccessArticle Evaluation of Enoyl-Acyl Carrier Protein Reductase Inhibitors as Pseudomonas aeruginosa Quorum-Quenching Reagents
Molecules 2010, 15(2), 780-792; doi:10.3390/molecules15020780
Received: 7 December 2009 / Revised: 21 January 2010 / Accepted: 27 January 2010 / Published: 3 February 2010
Cited by 15 | PDF Full-text (743 KB)
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen which is responsible for a wide range of infections. Production of virulence factors and biofilm formation by P. aeruginosa are partly regulated by cell-to-cell communication quorum-sensing systems. Identification of quorum-quenching reagents which block the quorum-sensing process can
[...] Read more.
Pseudomonas aeruginosa is an opportunistic pathogen which is responsible for a wide range of infections. Production of virulence factors and biofilm formation by P. aeruginosa are partly regulated by cell-to-cell communication quorum-sensing systems. Identification of quorum-quenching reagents which block the quorum-sensing process can facilitate development of novel treatment strategies for P. aeruginosa infections. We have used molecular dynamics simulation and experimental studies to elucidate the efficiencies of two potential quorum-quenching reagents, triclosan and green tea epigallocatechin gallate (EGCG), which both function as inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) from the bacterial type II fatty acid synthesis pathway. Our studies suggest that EGCG has a higher binding affinity towards ENR of P. aeruginosa and is an efficient quorum-quenching reagent. EGCG treatment was further shown to be able to attenuate the production of virulence factors and biofilm formation of P. aeruginosa. Full article
Open AccessCommunication The Solubility of Hen Lysozyme in Ethylammonium Nitrate/H2O Mixtures and a Novel Approach to Protein Crystallization
Molecules 2010, 15(2), 793-803; doi:10.3390/molecules15020793
Received: 16 December 2009 / Revised: 2 February 2010 / Accepted: 4 February 2010 / Published: 4 February 2010
Cited by 21 | PDF Full-text (206 KB)
Abstract
We report on the solubility of hen lysozyme (HEWL) in aqueous ethylammonium nitrate (EAN) as a function of water content. We find the solubility behavior to be complex, exhibiting both a maximum (400 mg/mL) at very high EAN content) and a minimum at
[...] Read more.
We report on the solubility of hen lysozyme (HEWL) in aqueous ethylammonium nitrate (EAN) as a function of water content. We find the solubility behavior to be complex, exhibiting both a maximum (400 mg/mL) at very high EAN content) and a minimum at intermediate EAN content. We exploit this solubility profile in a novel approach to generating crystals of hydrophilic proteins, based on rehydration of a high concentration protein solution. We describe the production of crystals of X-ray diffraction quality. Two related ionic liquid solvent systems, with the same solubility profiles but different effective pH characteristics, are identified for future evaluation. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessArticle Ancient Chinese Methods Are Remarkably Effective for the Preparation of Artemisinin-Rich Extracts of Qing Hao with Potent Antimalarial Activity
Molecules 2010, 15(2), 804-812; doi:10.3390/molecules15020804
Received: 11 January 2010 / Revised: 29 January 2010 / Accepted: 3 February 2010 / Published: 4 February 2010
Cited by 26 | PDF Full-text (123 KB)
Abstract
Ancient Chinese herbal texts as far back as the 4th Century Zhou hou bei ji fang describe methods for the use of Qing Hao (Artemisia annua) for the treatment of intermittent fevers. Today, the A. annua constituent artemisinin is an important
[...] Read more.
Ancient Chinese herbal texts as far back as the 4th Century Zhou hou bei ji fang describe methods for the use of Qing Hao (Artemisia annua) for the treatment of intermittent fevers. Today, the A. annua constituent artemisinin is an important antimalarial drug and the herb itself is being grown and used locally for malaria treatment although this practice is controversial. Here we show that the ancient Chinese methods that involved either soaking, (followed by wringing) or pounding, (followed by squeezing) the fresh herb are more effective in producing artemisinin-rich extracts than the usual current method of preparing herbal teas from the dried herb. The concentrations of artemisinin in the extracts was up to 20-fold higher than that in a herbal tea prepared from the dried herb, but the amount of total artemisinin extracted by the Chinese methods was much less than that removed in the herbal tea. While both extracts exhibited potent in vitro activities against Plasmodium falciparum, only the pounded juice contained sufficient artemisinin to suppress parasitaemia in P. berghei infected mice. The implications of these results are discussed in the context of malaria treatment using A. annua infusions. Full article
Open AccessArticle Microwave-Assisted and Efficient Solvent-free Knoevenagel Condensation. A Sustainable Protocol Using Porous Calcium Hydroxyapatite as Catalyst
Molecules 2010, 15(2), 813-823; doi:10.3390/molecules15020813
Received: 8 December 2009 / Revised: 21 January 2010 / Accepted: 21 January 2010 / Published: 4 February 2010
Cited by 35 | PDF Full-text (300 KB)
Abstract
A sustainable Knoevenagel condensation of a series of aldehydes with malononitrile and ethyl cyanoacetate is described. The process is based on the combination of microwave activation and hydroxyapatite catalysis under solvent-free conditions. Products are obtained in and high yields after short reaction times.
[...] Read more.
A sustainable Knoevenagel condensation of a series of aldehydes with malononitrile and ethyl cyanoacetate is described. The process is based on the combination of microwave activation and hydroxyapatite catalysis under solvent-free conditions. Products are obtained in and high yields after short reaction times. The effects of the specific surface of porous calcium hydroxyapatite and microwave activation are discussed. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Open AccessArticle Synthesis and Characterization of Long-Chain Tartaric Acid Diamides as Novel Ceramide-Like Compounds
Molecules 2010, 15(2), 824-833; doi:10.3390/molecules15020824
Received: 22 January 2010 / Revised: 1 February 2010 / Accepted: 3 February 2010 / Published: 5 February 2010
Cited by 7 | PDF Full-text (174 KB)
Abstract
Ceramides play a crucial role in the barrier function of the skin as well as in transmembrane signaling. In this study long aliphatic chain tartaric acid diamides able to replace ceramides in an in vitro model of the stratum corneum lipid matrix due
[...] Read more.
Ceramides play a crucial role in the barrier function of the skin as well as in transmembrane signaling. In this study long aliphatic chain tartaric acid diamides able to replace ceramides in an in vitro model of the stratum corneum lipid matrix due to their similar physico-chemical properties were synthesized from diacetoxysuccinic anhydride in four steps. Their pro-apoptotic effect on fibroblast cells was also investigated. Full article
Open AccessArticle Sesterterpenes and a New Sterol from the Marine Sponge Phyllospongia foliascens
Molecules 2010, 15(2), 834-841; doi:10.3390/molecules15020834
Received: 27 December 2009 / Revised: 19 January 2010 / Accepted: 21 January 2010 / Published: 5 February 2010
Cited by 4 | PDF Full-text (311 KB)
Abstract
A new scalarane sesterterpene, phyllofolactone M (1), and a new sterol, (24E)-5α,6α-epoxystigmasta-7,24(28)-dien-3β-ol (3), together with a known sesterterpene, phyllofolactone B (2), were isolated from the South China Sea sponge
[...] Read more.
A new scalarane sesterterpene, phyllofolactone M (1), and a new sterol, (24E)-5α,6α-epoxystigmasta-7,24(28)-dien-3β-ol (3), together with a known sesterterpene, phyllofolactone B (2), were isolated from the South China Sea sponge Phyllospongia foliascens. Their structures were elucidated by spectroscopic analysis and comparison with known compounds. In addition, previous NMR data assignments for the known sesterterpene phyllofolactone B (2) were revised. Full article
Open AccessArticle Seeking Polymeric Prodrugs of Norfloxacin. Part 2. Synthesis and Structural Analysis of Polyurethane Conjugates
Molecules 2010, 15(2), 842-856; doi:10.3390/molecules15020842
Received: 11 January 2010 / Revised: 30 January 2010 / Accepted: 3 February 2010 / Published: 5 February 2010
Cited by 9 | PDF Full-text (338 KB)
Abstract
Oligo(ε-caprolactone) and oligolactide were synthesized via ring-opening polymerization of cyclic esters in the presence of creatinine as initiators. Thus obtained oligomers were successfully used in the synthesis of novel polyurethane conjugates of norfloxacin. The structures of the polymers and conjugates were elucidated by
[...] Read more.
Oligo(ε-caprolactone) and oligolactide were synthesized via ring-opening polymerization of cyclic esters in the presence of creatinine as initiators. Thus obtained oligomers were successfully used in the synthesis of novel polyurethane conjugates of norfloxacin. The structures of the polymers and conjugates were elucidated by means of MALDI-TOF MS, NMR and IR studies. Full article
(This article belongs to the Special Issue Prodrugs)
Open AccessArticle Quercetin as a Potential Modulator of P-Glycoprotein Expression and Function in Cells of Human Pancreatic Carcinoma Line Resistant to Daunorubicin
Molecules 2010, 15(2), 857-870; doi:10.3390/molecules15020857
Received: 29 December 2009 / Revised: 28 January 2010 / Accepted: 3 February 2010 / Published: 9 February 2010
Cited by 33 | PDF Full-text (684 KB)
Abstract
P-glycoprotein (P-gp) is one of the ABC transporters responsible for the resistance of several tumours to successful chemotherapy. Numerous agents are capable of interfering with the P-gp-mediated export of drugs but unfortunately most of them produce serious side effects. Some plant polyphenols, including
[...] Read more.
P-glycoprotein (P-gp) is one of the ABC transporters responsible for the resistance of several tumours to successful chemotherapy. Numerous agents are capable of interfering with the P-gp-mediated export of drugs but unfortunately most of them produce serious side effects. Some plant polyphenols, including the flavonol quercetin (Q), manifest anti-neoplastic activity mainly due to their influence on cell cycle control and apoptosis. Reports are also available which show that Q may intensify action of cytostatic drugs and suppress the multidrug resistance (MDR) phenomenon. The study aimed at determination if Q sensitizes cells resistant to daunorubicin (DB) through its effect on P-gp expression and action. The experiments were conducted on two cell lines of human pancreatic carcinoma, resistant to DB EPP85-181RDB and sensitive EPP85-181P as a comparison. Cells of both lines were exposed to selected concentrations of Q and DB, and then membranous expression of P-gp and its transport function were examined. The influence on expression of gene for P-gp (ABCB1) was also investigated. Results of the studies confirmed that Q affects expression and function of P-gp in a concentration-dependent manner. Moreover it decreased expression of ABCB1. Thus, Q may be considered as a potential modulator of P-gp. Full article
Open AccessArticle A New 1,4-Diazepine from South China Sea Marine Sponge Callyspongia Species
Molecules 2010, 15(2), 871-877; doi:10.3390/molecules15020871
Received: 16 December 2009 / Revised: 6 January 2010 / Accepted: 26 January 2010 / Published: 10 February 2010
Cited by 12 | PDF Full-text (243 KB)
Abstract
A new 1,4-diazepine, callysponine (1), was isolated from a South China Sea Callyspongia sp. marine sponge, together with four known proline-based diketopiperazines: cyclo-(S-Pro-R-Leu) (2), cyclo-(S-Pro-R-Val) (3), cyclo-(S-Pro-
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A new 1,4-diazepine, callysponine (1), was isolated from a South China Sea Callyspongia sp. marine sponge, together with four known proline-based diketopiperazines: cyclo-(S-Pro-R-Leu) (2), cyclo-(S-Pro-R-Val) (3), cyclo-(S-Pro-R-Ala) (4), andcyclo-(S-Pro-R-Tyr) (5). The new structure was determined on the basis of NMR and MS analysis, and the absolute stereochemistry was defined by NOESY spectroscopy and optical rotation. The structures of the known compounds were identified by comparison of their spectroscopic data with those reported in the literature. Callysponine (1) did not inhibit the growth of HepG2 (hepatoma carcinoma cell), A549 (lung carcinoma cell), and HeLa (cervical cancer cell) cell lines. Full article
Open AccessArticle Synthesis, Cytotoxic and Antimalarial Activities of Benzoyl Thiosemicarbazone Analogs of Isoquinoline and Related Compounds
Molecules 2010, 15(2), 988-996; doi:10.3390/molecules15020988
Received: 13 January 2010 / Revised: 4 February 2010 / Accepted: 20 February 2010 / Published: 23 February 2010
Cited by 23 | PDF Full-text (139 KB)
Abstract
Thiosemicarbazone analogs of papaveraldine and related compounds 16 were synthesized and evaluated for cytotoxic and antimalarial activities. The cytotoxic activity was tested against HuCCA-1, HepG2, A549 and MOLT-3 human cancer cell lines. Thiosemicarbazones 15 displayed cytotoxicity toward all the
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Thiosemicarbazone analogs of papaveraldine and related compounds 16 were synthesized and evaluated for cytotoxic and antimalarial activities. The cytotoxic activity was tested against HuCCA-1, HepG2, A549 and MOLT-3 human cancer cell lines. Thiosemicarbazones 15 displayed cytotoxicity toward all the tested cell lines, while compounds 25 selectively showed potent activity against the MOLT-3 cell lines. Significantly, N(4)-phenyl-2-benzoylpyridine thiosemicarbazone 4 exhibited the most potent activity against HuCCA-1, HepG2, A549 and MOLT-3 cell lines with IC50 values of 0.03, 4.75, 0.04 and 0.004 µg/mL, respectively. In addition, 2-benzoylpyridine thio-semicarbazones 3 and 4 showed antimalarial activity against Plasmodium falciparum with IC50 of 10-7 to < 10-6 M. The study demonstrates the quite promising activity of analog 4 as a lead molecule for further development. Full article
Open AccessArticle Synthesis of 1-(4-Trifluoromethoxyphenyl)-2,5-dimethyl-3-(2-R-thiazol-4-yl)-1H-pyrroles via Chain Heterocyclization
Molecules 2010, 15(2), 997-1006; doi:10.3390/molecules15020997
Received: 26 December 2009 / Revised: 22 February 2010 / Accepted: 22 February 2010 / Published: 23 February 2010
Cited by 5 | PDF Full-text (191 KB)
Abstract
The title compounds, (4-trifluoromethoxyphenyl)-2,5-dimethyl-3-(2-R-thiazol-4-yl)-1H-pyrroles, were prepared in four steps starting from commercially available 4-trifluoromethoxyaniline. The pyrrole (second ring) was added in one step using the Paal-Knorr method. The thiazole (third ring) was added in three steps using chloroacylation with
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The title compounds, (4-trifluoromethoxyphenyl)-2,5-dimethyl-3-(2-R-thiazol-4-yl)-1H-pyrroles, were prepared in four steps starting from commercially available 4-trifluoromethoxyaniline. The pyrrole (second ring) was added in one step using the Paal-Knorr method. The thiazole (third ring) was added in three steps using chloroacylation with chloroacetonitrile followed by heterocyclization with thioamides/thioureas. Full article
Open AccessArticle Polysaccharides Coatings on Medical-Grade PVC: A Probe into Surface Characteristics and the Extent of Bacterial Adhesion
Molecules 2010, 15(2), 1007-1027; doi:10.3390/molecules15021007
Received: 4 January 2010 / Revised: 22 February 2010 / Accepted: 23 February 2010 / Published: 23 February 2010
Cited by 47 | PDF Full-text (906 KB)
Abstract
Medical-grade polyvinyl chloride was coated by polysaccharides through a novel physicochemical approach. An initial surface activation was performed foremost via diffuse coplanar surface barrier discharge plasma in air at ambient temperature and pressure. Then, radical graft copolymerization of acrylic acid through grafting-from pathway
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Medical-grade polyvinyl chloride was coated by polysaccharides through a novel physicochemical approach. An initial surface activation was performed foremost via diffuse coplanar surface barrier discharge plasma in air at ambient temperature and pressure. Then, radical graft copolymerization of acrylic acid through grafting-from pathway was directed to render a well-defined brush of high density, and finally a chitosan monolayer and chitosan/pectin alternating multilayer were bound onto the functionalized surfaces. Surface characteristics were systematically investigated using several probe techniques. In vitro bacterial adhesion and biofilm formation assays indicated that a single chitosan layer was incapable of hindering the adhesion of a Staphylococcus aureus bacterial strain, while up to 30% reduction was achieved by the chitosan/pectin layered assembly. On the other hand, chitosan and chitosan/pectin multilayer could retard Escherichia coli adhesion by 50% and 20%, respectively. Furthermore, plasma treated and graft copolymerized samples were also found effective to diminish the degree of adherence of Escherichia coli. Full article
(This article belongs to the Special Issue Macromolecules: Chemistry, Medicinal and Functional Materials)
Open AccessArticle Synthesis and Characterization of Novel Inorganic-Organic Hybrid Ru(II) Complexes and Their Application in Selective Hydrogenation
Molecules 2010, 15(2), 1028-1040; doi:10.3390/molecules15021028
Received: 31 December 2009 / Revised: 21 January 2010 / Accepted: 18 February 2010 / Published: 23 February 2010
Cited by 14 | PDF Full-text (190 KB)
Abstract
Novel Ru(II) complex-based hybrid inorganic-organic materials immobilized via a diamine co-ligand site instead of the conventional diphosphine ligand have been prepared. The complexes were prepared by two different methods: sol-gel and surface modification techniques. The structures of the desired materials were deduced by
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Novel Ru(II) complex-based hybrid inorganic-organic materials immobilized via a diamine co-ligand site instead of the conventional diphosphine ligand have been prepared. The complexes were prepared by two different methods: sol-gel and surface modification techniques. The structures of the desired materials were deduced by several available physical measurements like elemental analyses, infrared, FAB-MS and 1H-, 13C- and 31P-NMR spectroscopy. Due to a lack of solubility the structures of xerogel 3 and modified 4 were studied by solid state 13C-, 29Si- and 31P-NMR spectroscopy, infrared spectroscopy and EXAFS. These materials were stable enough to serve as hydrogenation catalysts. Selective hydrogenation of functionalized carbonyls in a,b-unsaturated compounds was successfully carried out under mild conditions in a basic medium using these complexes as catalysts. Full article
Open AccessArticle Synthesis and Biological activity of 4-(4,6-Disubstituted-pyrimidin-2-yloxy)phenoxy Acetates
Molecules 2010, 15(2), 1074-1081; doi:10.3390/molecules15021074
Received: 14 January 2010 / Revised: 1 February 2010 / Accepted: 20 February 2010 / Published: 23 February 2010
Cited by 5 | PDF Full-text (214 KB)
Abstract
Ten novel 4-(4,6-dimethoxypyrimidin-2-yloxy)phenoxy acetates and 4-(4,6-dimethylpyrimidin-2-yloxy)phenoxy acetates were synthesized with hydroquinone, 2-methylsulfonyl-4,6-disubstituted-pyrimidine and chloroacetic ester as starting materials. The products were characterized by IR, 1H-NMR, MS spectra and elemental analyses. Preliminary bioassay indicates that the target compounds possess high herbicidal activity against
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Ten novel 4-(4,6-dimethoxypyrimidin-2-yloxy)phenoxy acetates and 4-(4,6-dimethylpyrimidin-2-yloxy)phenoxy acetates were synthesized with hydroquinone, 2-methylsulfonyl-4,6-disubstituted-pyrimidine and chloroacetic ester as starting materials. The products were characterized by IR, 1H-NMR, MS spectra and elemental analyses. Preliminary bioassay indicates that the target compounds possess high herbicidal activity against monocotyledonous plants such as Digitaria sanguinalis L. at concentrations of 100 mg/L and 50 mg/L. Full article
Open AccessCommunication Remarkable Iodine-Catalyzed Synthesis of Novel Pyrrole- Bearing N-Polyaromatic β-Lactams
Molecules 2010, 15(2), 1082-1088; doi:10.3390/molecules15021082
Received: 22 December 2009 / Revised: 8 February 2010 / Accepted: 20 February 2010 / Published: 23 February 2010
Cited by 23 | PDF Full-text (165 KB)
Abstract
Because of their interesting biological properties various methods for the synthesis of substituted pyrroles are described in the literature. However, synthesis of pyrroles fused with a β-lactam ring has not been reported. Our group has demonstrated synthesis and biological evaluation of various β-lactams
[...] Read more.
Because of their interesting biological properties various methods for the synthesis of substituted pyrroles are described in the literature. However, synthesis of pyrroles fused with a β-lactam ring has not been reported. Our group has demonstrated synthesis and biological evaluation of various β-lactams as anticancer agents. The anticancer activities of these compounds have prompted us to study the synthesis of pyrroles bound to the β-lactams. We have identified an expeditious synthetic method for the preparation of pyrroles fused with β-lactams by reacting 3-amino β-lactams with acetonylacetone in the presence of catalytic amounts (5 mol%) of molecular iodine at room temperature. It has also been discovered that the reaction gives products under domestic and automated microwave oven irradiation. To our knowledge, there are no other prior reports that describe the synthesis of pyrrole-substituted β-lactams. Full article
(This article belongs to the Special Issue Organic Iodine Chemistry)
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Open AccessArticle Isolation and Identification of Two New Polyynes from a North American Ethnic Medicinal Plant--Oplopanax horridus (Smith) Miq.
Molecules 2010, 15(2), 1089-1096; doi:10.3390/molecules15021089
Received: 27 December 2009 / Revised: 4 February 2010 / Accepted: 19 February 2010 / Published: 23 February 2010
Cited by 18 | PDF Full-text (197 KB)
Abstract
Two new polyynes, named oplopantriol A (5) and oplopantriol B (6), were isolated from the root bark of Oplopanax horridus (Smith) Miq, an ethnic medicinal plant of North America, along with four known polyynes: (3S,8S)-falcarindiol
[...] Read more.
Two new polyynes, named oplopantriol A (5) and oplopantriol B (6), were isolated from the root bark of Oplopanax horridus (Smith) Miq, an ethnic medicinal plant of North America, along with four known polyynes: (3S,8S)-falcarindiol (1), oplopandiol (2), (11S,16S,9Z)-9,17-octadecadiene-12,14-diyne-1,11,16-triol, 1-acetate (3) and oplopandiol acetate (4). The structures of the new compounds were elucidated by detailed spectroscopic analyses, including 1D and 2D NMR techniques and chemical methods. The absolute configurations of the new compounds 5 and 6 were determined by comparing their optical rotation values with the hydrolysis products of the known compounds 3 and 4, respectively, derived from the same plant. On the basis of an analysis of their physical and chemical properties we show that the alkaline hydrolysis of 3 and 4 afforded the new compounds 5 and 6, respectively. Full article
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Review

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Open AccessReview Enantioselective, Organocatalytic Morita-Baylis-Hillman and Aza-Morita-Baylis-Hillman Reactions: Stereochemical Issues
Molecules 2010, 15(2), 709-734; doi:10.3390/molecules15020709
Received: 19 January 2010 / Revised: 25 January 2010 / Accepted: 29 January 2010 / Published: 1 February 2010
Cited by 62 | PDF Full-text (797 KB)
Abstract
Conscious of the importance that stereochemical issues may have on the design of efficient organocatalyts for both Morita-Baylis-Hillman and aza-Morita-Baylis-Hillman reaction we have analyzed them in this minireview. The so-called standard reactions involve “naked” enolates which therefore should lead to the syn adducts
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Conscious of the importance that stereochemical issues may have on the design of efficient organocatalyts for both Morita-Baylis-Hillman and aza-Morita-Baylis-Hillman reaction we have analyzed them in this minireview. The so-called standard reactions involve “naked” enolates which therefore should lead to the syn adducts as the major products, irrespective of the E, Z stereochemistry of the enolate. Accordingly, provided the second step is rate determining step, the design of successful bifunctional or polyfunctional catalysts has to consider the geometrical requirements imposed by the transition structures of the second step of these reactions. On the other hand, MBH and aza-MBH reactions co-catalyzed by (S)-proline and a secondary or tertiary amine (co-catalyst) involve the aldol-type condensation of either a 3-amino-substituted enamine, dienamine, or both, depending on the cases. A Zimmerman-Traxler mechanism defines the stereochemical issues regarding these co-catalyzed condensations which parallel those of the well established (S)-proline catalyzed aldol-like reactions. Full article
(This article belongs to the Special Issue Baylis-Hillman Reaction and Related Processes)
Open AccessReview 3-Nitropropionic Acid as a Tool to Study the Mechanisms Involved in Huntington’s Disease: Past, Present and Future
Molecules 2010, 15(2), 878-916; doi:10.3390/molecules15020878
Received: 9 December 2009 / Revised: 12 January 2010 / Accepted: 1 February 2010 / Published: 10 February 2010
Cited by 57 | PDF Full-text (361 KB)
Abstract
Huntington’s disease (HD) is an inheritable autosomal-dominant disorder whose causal mechanisms remain unknown. Experimental models have begun to uncover these pathways, thus helping to understand the mechanisms implicated and allowing for the characterization of potential targets for new therapeutic strategies. 3-Nitropropionic acid is
[...] Read more.
Huntington’s disease (HD) is an inheritable autosomal-dominant disorder whose causal mechanisms remain unknown. Experimental models have begun to uncover these pathways, thus helping to understand the mechanisms implicated and allowing for the characterization of potential targets for new therapeutic strategies. 3-Nitropropionic acid is known to produce in animals behavioural, biochemical and morphologic changes similar to those occurring in HD. For this reason, this phenotypic model is gaining attention as a valuable tool to mimick this disorder and further developing new therapies. In this review, we will focus on the past and present research of this molecule, to finally bring a perspective on what will be next in this promising field of study. Full article
(This article belongs to the Special Issue Neuroprotective Strategies)
Open AccessReview Organocatalyzed Asymmetric α-Oxidation, α-Aminoxylation and α-Amination of Carbonyl Compounds
Molecules 2010, 15(2), 917-958; doi:10.3390/molecules15020917
Received: 25 December 2009 / Revised: 27 January 2010 / Accepted: 5 February 2010 / Published: 11 February 2010
Cited by 85 | PDF Full-text (335 KB)
Abstract
Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing
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Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects and synthetic applications of α-oxidation, hydroxylation, aminoxylation, amination, hydrazination, hydroxyamination and related α-heteroatom functionalization of aldehydes, ketones and related active methylene compounds published during 2005–2009. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
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Open AccessReview Revealing the Power of the Natural Red Pigment Lycopene
Molecules 2010, 15(2), 959-987; doi:10.3390/molecules15020959
Received: 12 January 2010 / Revised: 29 January 2010 / Accepted: 3 February 2010 / Published: 23 February 2010
Cited by 60 | PDF Full-text (292 KB)
Abstract
By-products derived from food processing are attractive source for their valuable bioactive components and color pigments. These by-products are useful for development as functional foods, nutraceuticals, food ingredients, additives, and also as cosmetic products. Lycopene is a bioactive red colored pigment naturally occurring
[...] Read more.
By-products derived from food processing are attractive source for their valuable bioactive components and color pigments. These by-products are useful for development as functional foods, nutraceuticals, food ingredients, additives, and also as cosmetic products. Lycopene is a bioactive red colored pigment naturally occurring in plants. Industrial by-products obtained from the plants are the good sources of lycopene. Interest in lycopene is increasing due to increasing evidence proving its preventive properties toward numerous diseases. In vitro, in vivo and ex vivo studies have demonstrated that lycopene-rich foods are inversely associated to diseases such as cancers, cardiovascular diseases, diabetes, and others. This paper also reviews the properties, absorption, transportation, and distribution of lycopene and its by-products in human body. The mechanism of action and interaction of lycopene with other bioactive compounds are also discussed, because these are the crucial features for beneficial role of lycopene. However, information on the effect of food processing on lycopene stability and availability was discussed for better understanding of its characteristics. Full article
Open AccessReview Synthetic Applications of Chiral Unsaturated Epoxy Alcohols Prepared by Sharpless Asymmetric Epoxidation
Molecules 2010, 15(2), 1041-1073; doi:10.3390/molecules15021041
Received: 8 January 2010 / Revised: 9 February 2010 / Accepted: 20 February 2010 / Published: 23 February 2010
Cited by 21 | PDF Full-text (1044 KB)
Abstract
An overview of the synthesis and applications of chiral 2,3-epoxy alcohols containing unsaturated chains is presented. One of the fundamental synthetic routes to these compounds is Sharpless asymmetric epoxidation, which is reliable, highly chemoselective and enables easy prediction of the product enantioselectivity. Thus,
[...] Read more.
An overview of the synthesis and applications of chiral 2,3-epoxy alcohols containing unsaturated chains is presented. One of the fundamental synthetic routes to these compounds is Sharpless asymmetric epoxidation, which is reliable, highly chemoselective and enables easy prediction of the product enantioselectivity. Thus, unsaturated epoxy alcohols are readily obtained by selective oxidation of the allylic double bond in the presence of other carbon-carbon double or triple bonds. The wide availability of epoxy alcohols with unsaturated chains, the versatility of the epoxy alcohol functionality (e.g. regio- and stereo-selective ring opening; oxidation; and reduction), and the arsenal of established alkene chemistries, make unsaturated epoxy alcohols powerful starting materials for the synthesis of complex targets such as biologically active molecules. The popularization of ring-closing metathesis has further increased their value, making them excellent precursors to cyclic compounds. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
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