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Molecules, Volume 13, Issue 10 (October 2008), Pages 2340-2703

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Research

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Open AccessArticle Antibacterial Properties of 3 H-Spiro[1-benzofuran-2,1’-cyclohexane] Derivatives from Heliotropium filifolium
Molecules 2008, 13(10), 2385-2393; doi:10.3390/molecules13102385
Received: 3 July 2008 / Revised: 27 August 2008 / Accepted: 16 September 2008 / Published: 1 October 2008
Cited by 18 | PDF Full-text (194 KB) | HTML Full-text | XML Full-text
Abstract
A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3’-hydroxy-2’,2’,6’-trimethyl-3H-spiro[1-benzo-furan-2,1’-cyclohexane]-5-carboxylic acid(2), methyl 3’-acetyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (3), methyl 3’-isopentanoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (4) and methyl 3’-benzoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (5).Compounds 2-5 were identified by their spectroscopic analogies [...] Read more.
A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3’-hydroxy-2’,2’,6’-trimethyl-3H-spiro[1-benzo-furan-2,1’-cyclohexane]-5-carboxylic acid(2), methyl 3’-acetyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (3), methyl 3’-isopentanoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (4) and methyl 3’-benzoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (5).Compounds 2-5 were identified by their spectroscopic analogies with filifolinol (1), and their structures confirmed by chemical correlation with 1. The antimicrobial properties of the compounds were tested against Gram positive and Gram negative bacteria. Some of them proved to be active against Gram positive, but inactive against Gram negative bacteria. In searching for structure-activity relationships from the obtained MIC values, lipophilicity was shown to be an important variable. Full article
(This article belongs to the Special Issue Spiro Compounds)
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Open AccessArticle Methyl Mercapturate Synthesis: An Efficient, Convenient and Simple Method
Molecules 2008, 13(10), 2394-2407; doi:10.3390/molecules13102394
Received: 25 July 2008 / Revised: 9 September 2008 / Accepted: 26 September 2008 / Published: 1 October 2008
Cited by 7 | PDF Full-text (219 KB) | HTML Full-text | XML Full-text
Abstract
A safe and simple method for methyl S-arylmercapturate synthesis is described. Thirteen such compounds, to be used afterwards in metabolism studies, have been obtained with yields ranging from 71 to 99.6%. These compounds were obtained using a sulfa-Michael addition and synthesized by [...] Read more.
A safe and simple method for methyl S-arylmercapturate synthesis is described. Thirteen such compounds, to be used afterwards in metabolism studies, have been obtained with yields ranging from 71 to 99.6%. These compounds were obtained using a sulfa-Michael addition and synthesized by adding the corresponding thiophenols to a mixture composed of methyl 2-acetamidoacrylate (MAA), potassium carbonate and a phase transfer catalyst, Aliquat 336. MAA, the initial synthon, was itself isolated in quasi quantitative yield following a fully described synthesis. Full article
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Open AccessArticle Molecular Weight and Monosaccharide Composition of Astragalus Polysaccharides
Molecules 2008, 13(10), 2408-2415; doi:10.3390/molecules13102408
Received: 22 August 2008 / Revised: 24 September 2008 / Accepted: 26 September 2008 / Published: 1 October 2008
Cited by 17 | PDF Full-text (298 KB) | HTML Full-text | XML Full-text
Abstract
Two polysaccharides (APS-I and APS-II) were isolated from the water extract of Radix Astragali and purified through ethanol precipitation, deproteination and by ion-exchange and gel-filtration chromatography. Their molecular weight was determined using high performance liquid chromatography and gel permeation chromatography (HPLC-GPC) and [...] Read more.
Two polysaccharides (APS-I and APS-II) were isolated from the water extract of Radix Astragali and purified through ethanol precipitation, deproteination and by ion-exchange and gel-filtration chromatography. Their molecular weight was determined using high performance liquid chromatography and gel permeation chromatography (HPLC-GPC) and their monosaccharide composition was analyzed by TLC and HPLC methods, using a refractive index detector (RID) and an NH2 column. It was shown that APS-I consisted of arabinose and glucose and APS-II consisted of rhamnose, arabinose and glucose, in a molar ratio of 1:3.45 and 1:6.25:17.86, respectively. The molecular weights (Mw) of APS-I and APS-II were 1,699,100 Da and 1,197,600 Da, respectively. Full article
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Open AccessArticle Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures
Molecules 2008, 13(10), 2416-2425; doi:10.3390/molecules13102416
Received: 16 April 2008 / Accepted: 27 April 2008 / Published: 1 October 2008
Cited by 11 | PDF Full-text (185 KB) | HTML Full-text | XML Full-text
Abstract
A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with [...] Read more.
A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17b-Dihydroxyandrost-4-en-3-one (2), 11b-hydroxyandrost-4-en-3,17-dione (3), 11b,17a,20b,21-tetrahydroxypregn-4-en-3-one (4) and prednisolone (5) were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp. Full article
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Open AccessArticle Discovery of a Novel CCR5 Antagonist Lead Compound Through Fragment Assembly
Molecules 2008, 13(10), 2426-2441; doi:10.3390/molecules13102426
Received: 30 September 2008 / Revised: 18 September 2008 / Accepted: 18 September 2008 / Published: 1 October 2008
Cited by 17 | PDF Full-text (463 KB) | HTML Full-text | XML Full-text
Abstract
CCR5, as the major co-receptor for HIV-1 entry, is an attractive novel target for the pharmaceutical industry in the HIV-1 therapeutic area. In this study, based on the structures of maraviroc and 1,4-bis(4-(7-chloroquinolin-4-yl)piperazin-1-yl)butane-1,4-dione (1), which was identified using structure-based virtual screening in [...] Read more.
CCR5, as the major co-receptor for HIV-1 entry, is an attractive novel target for the pharmaceutical industry in the HIV-1 therapeutic area. In this study, based on the structures of maraviroc and 1,4-bis(4-(7-chloroquinolin-4-yl)piperazin-1-yl)butane-1,4-dione (1), which was identified using structure-based virtual screening in conjunction with a calcium mobilization assay, a series of novel small molecule CCR5 antagonists have been designed and synthesized through fragment assembly. Preliminary SARs were obtained, which are in good agreement with the molecular binding model and should prove helpful for future antagonist design. The novel scaffold presented here might also be useful in the development of maraviroc-derived second generation CCR5 antagonists. Full article
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Open AccessArticle Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors
Molecules 2008, 13(10), 2442-2461; doi:10.3390/molecules13102442
Received: 11 April 2008 / Revised: 19 September 2008 / Accepted: 19 September 2008 / Published: 1 October 2008
Cited by 25 | PDF Full-text (1160 KB) | HTML Full-text | XML Full-text
Abstract
HIV-1 integrase (IN) is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking [...] Read more.
HIV-1 integrase (IN) is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking study to investigate the potential interactions of the title compounds with essential amino acids on the IN active site. Full article
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Open AccessArticle Alkaloids Induce Programmed Cell Death in Bloodstream Forms of Trypanosomes (Trypanosoma b. brucei)
Molecules 2008, 13(10), 2462-2473; doi:10.3390/molecules13102462
Received: 30 June 2008 / Revised: 5 September 2008 / Accepted: 30 September 2008 / Published: 3 October 2008
Cited by 35 | PDF Full-text (203 KB) | HTML Full-text | XML Full-text
Abstract
The potential induction of a programmed cell death (PCD) in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, [...] Read more.
The potential induction of a programmed cell death (PCD) in Trypanosoma b. brucei by 55 alkaloids of the quinoline, quinolizidine, isoquinoline, indole, terpene, tropane, steroid, and piperidine type was studied by measuring DNA fragmentation and changes in mitochondrial membrane potential. For comparison, the induction of apoptosis by the same alkaloids in human leukemia cells (Jurkat APO-S) was tested. Several alkaloids of the isoquinoline, quinoline, indole and steroidal type (berberine, chelerythrine, emetine, sanguinarine, quinine, ajmalicine, ergotamine, harmine, vinblastine, vincristine, colchicine, chaconine, demissidine and veratridine) induced programmed cell death, whereas quinolizidine, tropane, terpene and piperidine alkaloids were mostly inactive. Effective PCD induction (EC50 below 10 µM) was caused in T. brucei by chelerythrine, emetine, sanguinarine, and chaconine. The active alkaloids can be characterized by their general property to inhibit protein biosynthesis, to intercalate DNA, to disturb membrane fluidity or to inhibit microtubule formation. Full article
(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)
Open AccessArticle Norcyperone, a Novel Skeleton Norsesquiterpene from Cyperus rotundus L.
Molecules 2008, 13(10), 2474-2481; doi:10.3390/molecules13102474
Received: 21 August 2008 / Revised: 25 September 2008 / Accepted: 26 September 2008 / Published: 10 October 2008
Cited by 17 | PDF Full-text (243 KB) | HTML Full-text | XML Full-text
Abstract
A novel norsesquiterpene, named norcyperone (1), and three known compounds: (-)-clovane-2,9-diol (2), rosenonolactone (3), and 5a,8a-epidioxy-(20S,22E,24R)-ergosta-6,22-dien-3β-ol (4) were isolated from the rhizomes of Cyperus rotundus L. The structure of 1 [...] Read more.
A novel norsesquiterpene, named norcyperone (1), and three known compounds: (-)-clovane-2,9-diol (2), rosenonolactone (3), and 5a,8a-epidioxy-(20S,22E,24R)-ergosta-6,22-dien-3β-ol (4) were isolated from the rhizomes of Cyperus rotundus L. The structure of 1 was elucidated as 8,11,11-trimethylbicyclo[5.3.1]undecane-5a, 8a-epoxy-3-one on the basis of extensive spectroscopic analyses, including 1D- and 2D-NMR, MS experiments, and single-crystal X-ray diffraction. This is the first report of a 8,11,11-trimethyl- bicyclo[5.3.1]undecane-3-one type norsesquiterpene with a tetrahydrofuran ring at C-5 and C-8. Full article
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Open AccessArticle Variation of Ursolic Acid Content in Eight Ocimum Species from Northeastern Brazil
Molecules 2008, 13(10), 2482-2487; doi:10.3390/molecules13102482
Received: 27 June 2008 / Revised: 16 September 2008 / Accepted: 16 September 2008 / Published: 14 October 2008
Cited by 38 | PDF Full-text (345 KB) | HTML Full-text | XML Full-text
Abstract
Ursolic acid is a very important compound due to its biological potential as an anti-inflammatory, trypanocidal, antirheumatic, antiviral, antioxidant and antitumoral agent. This study presents the HPLC analysis of ursolic acid (UA) content in eight different Ocimum species: O. americanum L., O. [...] Read more.
Ursolic acid is a very important compound due to its biological potential as an anti-inflammatory, trypanocidal, antirheumatic, antiviral, antioxidant and antitumoral agent. This study presents the HPLC analysis of ursolic acid (UA) content in eight different Ocimum species: O. americanum L., O. basilicum L, O. basilicum var purpurascens Benth, O. basilicum var. minimum L, O. gratissimum L, O. micranthum Willd, O. selloi Benth. and O. tenuiflorum L. grown in Northeastern Brazil. In these Ocimum species, UA was detected in different yields, with O. tenuiflorum showing the highest content (2.02%). This yield is very significant when compared with other sources of UA. Full article
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Open AccessArticle A Comparative Study of the Radical-scavenging Activity of the Phenolcarboxylic Acids Caffeic Acid, p-Coumaric Acid, Chlorogenic Acid and Ferulic Acid, With or Without 2-Mercaptoethanol, a Thiol, Using the Induction Period Method
Molecules 2008, 13(10), 2488-2499; doi:10.3390/molecules13102488
Received: 1 September 2008 / Revised: 7 October 2008 / Accepted: 9 October 2008 / Published: 15 October 2008
Cited by 28 | PDF Full-text (200 KB) | HTML Full-text | XML Full-text
Abstract
Phenolcarboxylic acid antioxidants do not act in vivo as radical-scavengers in isolation, but rather together with GSH (glutathione), a coantioxidant, they constitute an intricate antioxidant network. Caffeic acid, p-coumaric acid, ferulic acid and chlorogenic acid with or without 2-mercaptoethanol (ME), as a substitute for GSH, was investigated by the induction period (IP) method for polymerization of methyl methacrylate (MMA) initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN, a source of alkyl radicals, R.) and benzoyl peroxide (BPO, a source of peroxy radicals, PhCOO.) using differential scanning calorimetry (DSC). Upon PhCOO. radical scavenging, the stoichiometric factors (n, number of free radical trapped by one mole of antioxidant) for caffeic acid, ferulic acid, p-coumaric acid and chlorogenic acid were 2.4, 1.8, 1.7 and 0.9, whereas upon R. radical scavenging, the corresponding values were 1.3, 1.2, 1.0 and 0.8, respectively. Antioxidants with n values close to 2 suggest the stepwise formation of semiquinone radicals and quinones. By contrast, those with n values close to 1 suggest the formation of dimers after single-electron oxidation, possibly due to recombination of corresponding aryloxy radicals. The ratio of the rate constant of inhibition to that of propagation (kinh/kp) declined in the order chlorogenic acid > p-coumaric acid > ferulic acid > caffeic acid. The ratio of the observed IP for the phenolcarboxylic acid/2-mercapto-ethanol (ME) mixture (1:1 molar ratio) (A) to the calculated IP (the simple sum of phenol acid antioxidant and ME) (B) was investigated. Upon R. scavenging, the caffeic acid or p-coumaric acid/ME mixture was A/B > 1, particularly the former was 1.2, suggesting a synergic effect. By contrast, upon PhCOO. scavenging, the corresponding mixture was A/B < 1, particularly the latter was 0.7, suggesting an antagonistic effect. Upon both radicals scavenging, the A/B for the ferulic acid or chlorogenic acid/ME mixture was approximately 1. The reported beneficial antioxidant, anti-inflammatory and anticancer effects of caffeic acid and p-coumaric acid may be related to their prooxidant-antioxidant balance in the presence of GSH. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
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Open AccessArticle Two New Phenolic Glycosides from Viscum articulatum
Molecules 2008, 13(10), 2500-2508; doi:10.3390/molecules13102500
Received: 23 September 2008 / Revised: 10 October 2008 / Accepted: 10 October 2008 / Published: 15 October 2008
Cited by 6 | PDF Full-text (214 KB) | HTML Full-text | XML Full-text
Abstract
Two new phenolic glycosides, 1-O-benzyl-[5-O-benzoyl-β-D-apiofuranosyl (1→2)]-β-D-glucopyranoside (1), and 4`-hydroxy-7,3`-dimethoxyflavan-5-O- β-D-gluco-pyranoside (2), together with nine known flavanones 3 - 11, have been isolated from the dried whole plants of Viscum articulatum.Their [...] Read more.
Two new phenolic glycosides, 1-O-benzyl-[5-O-benzoyl-β-D-apiofuranosyl (1→2)]-β-D-glucopyranoside (1), and 4`-hydroxy-7,3`-dimethoxyflavan-5-O- β-D-gluco-pyranoside (2), together with nine known flavanones 3 - 11, have been isolated from the dried whole plants of Viscum articulatum.Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Compound 9 showed weak anti-HIV-1 activity. Full article
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Open AccessArticle The Effect of Ginkgo Biloba (EGb 761) on Epileptic Activity in Rabbits
Molecules 2008, 13(10), 2509-2520; doi:10.3390/molecules13102509
Received: 12 September 2008 / Revised: 8 October 2008 / Accepted: 9 October 2008 / Published: 16 October 2008
Cited by 10 | PDF Full-text (186 KB) | HTML Full-text | XML Full-text
Abstract
Different animal models are used to evaluate the process of epileptogenesis. In this investigation the kindling model of epilepsy was used. The epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus with electric stimuli. We presumed that the extracts [...] Read more.
Different animal models are used to evaluate the process of epileptogenesis. In this investigation the kindling model of epilepsy was used. The epileptic focus was induced in Chinchilla rabbits by stimulation of the hippocampus with electric stimuli. We presumed that the extracts of Ginkgo biloba affect the formation of kindling epilepsy. Bioelectric activity of the brain was registered throughout the development of kindling with and without standardized extracts from dried ginkgo leaves (EGb 761). For each animal the following has been determined: the values of the minimum current strength necessary for the origination of threshold after-discharge (AD) – discharges appearing after the cessation of stimulation; duration of the threshold AD; number of stimulations necessary for the origination of full kindling; time latency for the development of full kindling; number of spontaneous epileptogenic discharges manifested in EEG two days following the formation of full kindling during 60-minute registration. The results show that the process of epileptogenesis was influenced by EGb 761. It has been established that if the animals received EGb 761, significantly weaker minimum current strength was necessary for the development of the epileptogenic focus and the AD were longer, while the number of necessary electrostimulations for the appearance of full kindling was less and the latency was shorter. Full article
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Open AccessArticle Evaluation of the Antioxidant Activity of Syzygium cumini Leaves
Molecules 2008, 13(10), 2545-2556; doi:10.3390/molecules13102545
Received: 21 August 2008 / Revised: 10 October 2008 / Accepted: 13 October 2008 / Published: 16 October 2008
Cited by 38 | PDF Full-text (515 KB) | HTML Full-text | XML Full-text
Abstract
The antioxidant activity of Syzygium cumini leaf extracts was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging and ferric-reducing antioxidant power (FRAP) assays. The methanolic extract and its four water, ethyl acetate, chloroform, and n-hexane fractions were prepared and subjected to antioxidant [...] Read more.
The antioxidant activity of Syzygium cumini leaf extracts was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging and ferric-reducing antioxidant power (FRAP) assays. The methanolic extract and its four water, ethyl acetate, chloroform, and n-hexane fractions were prepared and subjected to antioxidant evaluation. The results showed that the ethyl acetate fraction had stronger antioxidant activity than the other ones. HPLC data indicated that S. cumini leaf extracts contained phenolic compounds, such as ferulic acid and catechin, responsible for their antioxidant activity. A significant linear relationship between antioxidant potency, free radical-scavenging ability and the content of phenolic compounds of leaf extracts supported this observation. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
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Open AccessArticle Synthesis and Anticonvulsant Activity of Some Quinazolin-4-(3H)-one Derivatives
Molecules 2008, 13(10), 2557-2569; doi:10.3390/molecules13102557
Received: 4 September 2008 / Revised: 18 September 2008 / Accepted: 15 October 2008 / Published: 16 October 2008
Cited by 43 | PDF Full-text (243 KB) | HTML Full-text | XML Full-text
Abstract
A number of 3-substituted-2-(substituted-phenoxymethyl) quinazolin-4(3H)-one derivatives 4a,b, 5a-c, 6, 7a-f, 8a-e and 9a,b have been synthesized. Their structures have been elucidated on the basis of elemental analyses and spectroscopic studies (IR, 1H-NMR, MS). A preliminary evaluation of the anticonvulsant [...] Read more.
A number of 3-substituted-2-(substituted-phenoxymethyl) quinazolin-4(3H)-one derivatives 4a,b, 5a-c, 6, 7a-f, 8a-e and 9a,b have been synthesized. Their structures have been elucidated on the basis of elemental analyses and spectroscopic studies (IR, 1H-NMR, MS). A preliminary evaluation of the anticonvulsant activity of the prepared compounds has indicated that compounds 4b, 7b-f, 8a and 9b exhibit significant anticonvulsant activity, while compounds 6, 8b and 8d show mild to moderate activity. Full article
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Open AccessArticle The Synthesis of 1-(4-Triethoxysilyl)phenyl)-4,4,4-trifluoro-1,3-butanedione, a Novel Trialkoxysilane Monomer for the Preparation of Functionalized Sol-gel Matrix Materials
Molecules 2008, 13(10), 2601-2607; doi:10.3390/molecules13102601
Received: 23 September 2008 / Revised: 3 October 2008 / Accepted: 7 October 2008 / Published: 20 October 2008
Cited by 1 | PDF Full-text (158 KB) | HTML Full-text | XML Full-text
Abstract The title compound, 1-(4-triethoxysilyl)phenyl)-4,4,4-trifluoro-1,3-butanedione, was synthesized in a three-step sequence starting from 2-(4-bromophenyl)propene. Containing both a trialkoxysilyl and a substituted 1,3-butanedione functional grouping within its structure, this new silane is a viable starting material for the preparation of functionalized sol-gel materials. Full article
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Open AccessArticle Surface-enhanced Raman Spectral Measurements of 5-Fluorouracil in Saliva
Molecules 2008, 13(10), 2608-2627; doi:10.3390/molecules13102608
Received: 8 August 2008 / Revised: 16 October 2008 / Accepted: 20 October 2008 / Published: 22 October 2008
Cited by 23 | PDF Full-text (462 KB) | HTML Full-text | XML Full-text
Abstract
The ability of surface-enhanced Raman spectroscopy (SERS) to measure 5-fluorouracil (5-FU) in saliva is presented. The approach is based on the capacity of Raman spectroscopy to provide a unique spectral signature for virtually every chemical, and the ability of SERS to provide [...] Read more.
The ability of surface-enhanced Raman spectroscopy (SERS) to measure 5-fluorouracil (5-FU) in saliva is presented. The approach is based on the capacity of Raman spectroscopy to provide a unique spectral signature for virtually every chemical, and the ability of SERS to provide μg/mL sensitivity. A simple sampling method, that employed 1-mm glass capillaries filled with silver-doped sol-gels, was developed to isolate 5-FU from potential interfering chemical components of saliva and simultaneously provide SERSactivity. The method involved treating a 1 mL saliva sample with 1 mL of acetic acid, drawing 10 μL of sample into a SERS-active capillary by syringe, and then measuring the SER spectrum. Quality SER spectra were obtained for samples containing as little as 2 μg of 5-FU in 1 mL saliva. The entire process, the acid pretreatment, extraction and spectral measurement, took less than 5 minutes. The SERS of 5-fluorouridine and 5-fluoro-2’-deoxyuridine, two major metabolites of 5-FU, were also measured and shown to have unique spectral peaks. These measurements suggest that disposable SERS-active capillaries could be used to measure 5-FU and metabolite concentrations in chemotherapy patient saliva, thereby providing metabolic data that would allow regulating dosage. Tentative vibrational mode assignments for 5-FU and its metabolites are also given. Full article
(This article belongs to the Special Issue 5-Fluorouracil)
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Open AccessCommunication Diastereoselective Synthesis of Cyclopentanediols by InCl3/Al Mediated Intramolecular Pinacol Coupling Reaction in Aqueous Media
Molecules 2008, 13(10), 2652-2658; doi:10.3390/molecules13102652
Received: 2 August 2008 / Revised: 14 October 2008 / Accepted: 15 October 2008 / Published: 27 October 2008
Cited by 4 | PDF Full-text (192 KB) | HTML Full-text | XML Full-text
Abstract A “green” and practical intramolecular pinacol coupling reaction promoted by InCl3/Al catalysts in aqueous media has been developed. Under mild conditions, a novel class of polysubstituted cyclopentane-1,2-diols have been obtained with excellent diastereoselectivity. Full article
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Open AccessArticle Overexpression of the Pdx-1 Homeodomain Transcription Factor Impairs Glucose Metabolism in Cultured Rat Hepatocytes
Molecules 2008, 13(10), 2659-2673; doi:10.3390/molecules13102659
Received: 30 September 2008 / Revised: 20 October 2008 / Accepted: 24 October 2008 / Published: 28 October 2008
PDF Full-text (412 KB) | HTML Full-text | XML Full-text
Abstract
The Pdx-1 transcription factor plays crucial functions both during pancreas development and in the adult β cells. Previous studies have indicated that ectopic Pdx-1 expression in liver or intestinal primary and immortalized cells is sufficient to promote activation of insulin gene expression. [...] Read more.
The Pdx-1 transcription factor plays crucial functions both during pancreas development and in the adult β cells. Previous studies have indicated that ectopic Pdx-1 expression in liver or intestinal primary and immortalized cells is sufficient to promote activation of insulin gene expression. This work is focused on the molecular and physiological consequences of Pdx-1 overexpression in liver cells. We present evidence that Pdx-1 affects the level of expression of one of the four mammalian hexokinase isozymes. These are glucose phosphorylating enzymes involved in essential cellular functions such as glucose sensing, metabolic energy production and apoptosis. Specifically, our data show that over-expression of Pdx-1 in cultured hepatocytes is able to repress the expression of hexokinase 2 (Hxk 2) and the phenomenon is mediated via binding of Pdx-1 to a specific sequence on the Hxk 2 gene promoter. As a consequence, liver cells over-expressing Pdx-1 present interesting alterations concerning glucose metabolism. Full article
(This article belongs to the Special Issue Nucleic Acids)
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Review

Jump to: Research

Open AccessReview Novel Strategies to Improve the Anticancer Action of 5-Fluorouracil by Using Drug Delivery Systems
Molecules 2008, 13(10), 2340-2369; doi:10.3390/molecules13102340
Received: 22 April 2008 / Revised: 16 September 2008 / Accepted: 16 September 2008 / Published: 1 October 2008
Cited by 69 | PDF Full-text (717 KB)
Abstract
Because of the fundamental importance of new therapeutic routes for cancer treatment, a number of systems based on colloidal particles as vehicles for the delivery of the anticancer drug 5-fluorouracil have been devised. The target is always to provide the proper dose [...] Read more.
Because of the fundamental importance of new therapeutic routes for cancer treatment, a number of systems based on colloidal particles as vehicles for the delivery of the anticancer drug 5-fluorouracil have been devised. The target is always to provide the proper dose of the antitumor agent only at the desired locus of action, thus reducing the unwanted side effects. In this review, the main strategies and the more significant results in the development of 5-fluorouracil carriers for cancer treatment are discussed. Full article
(This article belongs to the Special Issue 5-Fluorouracil)
Open AccessReview Radiation- and Photo-induced Activation of 5-Fluorouracil Prodrugs as a Strategy for the Selective Treatment of Solid Tumors
Molecules 2008, 13(10), 2370-2384; doi:10.3390/molecules13102370
Received: 8 September 2008 / Revised: 22 September 2008 / Accepted: 22 September 2008 / Published: 1 October 2008
Cited by 16 | PDF Full-text (248 KB) | HTML Full-text | XML Full-text
Abstract
5-Fluorouracil (5-FU) is used widely as an anticancer drug to treat solid cancers, such as colon, breast, rectal, and pancreatic cancers, although its clinical application is limited because 5-FU has gastrointestinal and hematological toxicity. Many groups are searching for prodrugs with functions [...] Read more.
5-Fluorouracil (5-FU) is used widely as an anticancer drug to treat solid cancers, such as colon, breast, rectal, and pancreatic cancers, although its clinical application is limited because 5-FU has gastrointestinal and hematological toxicity. Many groups are searching for prodrugs with functions that are tumor selective in their delivery and can be activated to improve the clinical utility of 5-FU as an important cancer chemotherapeutic agent. UV and ionizing radiation can cause chemical reactions in a localized area of the body, and these have been applied in the development of site-specific drug activation and sensitization. In this review, we describe recent progress in the development of novel 5-FU prodrugs that are activated site specifically by UV light and ionizing radiation in the tumor microenvironment. We also discuss the chemical mechanisms underlying this activation. Full article
(This article belongs to the Special Issue 5-Fluorouracil)
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Open AccessReview Advances of Modern Chromatographic and Electrophoretic Methods in Separation and Analysis of Flavonoids
Molecules 2008, 13(10), 2521-2544; doi:10.3390/molecules13102521
Received: 18 August 2008 / Revised: 30 September 2008 / Accepted: 7 October 2008 / Published: 16 October 2008
Cited by 37 | PDF Full-text (298 KB) | HTML Full-text | XML Full-text
Abstract
Flavonoids, one of the largest groups of secondary metabolites, are widespread in vegetable crops such as herbs, fruits, vegetables, grains, seeds and derived foods such as juices, wines, oils, etc. They receive considerable attention due to their biological and physiological importance. [...] Read more.
Flavonoids, one of the largest groups of secondary metabolites, are widespread in vegetable crops such as herbs, fruits, vegetables, grains, seeds and derived foods such as juices, wines, oils, etc. They receive considerable attention due to their biological and physiological importance. Hundreds of publications on the analysis of flavonoids have appeared over the past decade. Traditional and more advanced techniques have come to prominence for sample preparation, separation, detection, and identification. This review intends to provide an updated, concise overview on the recent development and trends of separation, identification and quantification for flavonoids by modern chromatographic and spectrophotometric analytical techniques, including gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE). The sample preparation before analysis is also briefly summarized. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
Open AccessReview Recent Synthetic Approaches Toward Non-anomeric Spiroketals in Natural Products
Molecules 2008, 13(10), 2570-2600; doi:10.3390/molecules13102570
Received: 18 July 2008 / Revised: 29 September 2008 / Accepted: 15 October 2008 / Published: 17 October 2008
Cited by 35 | PDF Full-text (405 KB) | HTML Full-text | XML Full-text
Abstract
Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biological activity of the compounds containing them. Most stable spiroketal [...] Read more.
Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biological activity of the compounds containing them. Most stable spiroketal stereoisomers, including those benefiting from conformational anomeric effects (gauche conformers can be more stable than anti conformers because of a contra-steric stabilizing effect), are obtained easily under acidic conditions that permit acetal heterolysis (formation of tertiary oxycarbenium ion intermediates). The synthesis of less stable stereoisomers requires stereoselective acetal forming reactions that do not permit their equilibration with their most stable stereoisomers or, in the case of suitably substituted derivatives, concomitant reactions generating tricyclic products that quench the less stable spiroketal conformers. Ingenuous approaches have been recently developed for the synthesis of naturally occurring [6,6]- and [5,6]-nonanomeric spiroketals and analogues. The identification of several parameters that can influence the stereochemical outcome of spirocyclization processes has led to seminal improvements in the selective preparation of the non-anomeric isomers that are discussed herein. This review also gives an up-dated view of conformational anomeric effect which represents a small fraction of the enthalpic anomeric effect that makes gem-dioxy substituted compounds much more stable that their 1,n-dioxy substituted isomers (n > 1). Although models assuming sp3-hybridized oxygen atoms have been very popular (rabbit ears for the two non-bonding electron pairs of oxygen atom), sp2-hybridized oxygen atoms are used to describe the conformational anomeric effect. Full article
(This article belongs to the Special Issue Spiro Compounds)
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Open AccessReview Anti-carcinogenic Effects of the Flavonoid Luteolin
Molecules 2008, 13(10), 2628-2651; doi:10.3390/molecules13102628
Received: 17 September 2008 / Revised: 17 October 2008 / Accepted: 21 October 2008 / Published: 22 October 2008
Cited by 102 | PDF Full-text (330 KB) | HTML Full-text | XML Full-text
Abstract
Luteolin is a flavonoid which is part of our daily nutrition in relatively low amounts (less than 1 mg/day). Nevertheless, some epidemiological studies suggest an inverse correlation between luteolin intake and the risk of some cancer types. Luteolin displays specific anti-inflammatory and [...] Read more.
Luteolin is a flavonoid which is part of our daily nutrition in relatively low amounts (less than 1 mg/day). Nevertheless, some epidemiological studies suggest an inverse correlation between luteolin intake and the risk of some cancer types. Luteolin displays specific anti-inflammatory and anti-carcinogenic effects, which can only partly be explained by its anti-oxidant and free radical scavenging capacities. Luteolin can delay or block the development of cancer cells in vitro and in vivo by protection from carcinogenic stimuli, by inhibition of tumor cell proliferation, by induction of cell cycle arrest and by induction of apoptosis via intrinsic and extrinsic signaling pathways. When compared to other flavonoids, luteolin was usually among the most effective ones, inhibiting tumor cell proliferation with IC50 values between 3 and 50 μM in vitro and in vivo by 5 to 10 mg/kg i.p., intragastric application of 0.1–0.3 mg/kg/d, or as food additive in concentrations of 50 to 200 ppm. Luteolin has been shown to penetrate into human skin, making it also a candidate for the prevention and treatment of skin cancer. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
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Open AccessReview Biosynthesis and Genetic Regulation of Proanthocyanidins in Plants
Molecules 2008, 13(10), 2674-2703; doi:10.3390/molecules13102674
Received: 11 August 2008 / Revised: 21 October 2008 / Accepted: 23 October 2008 / Published: 28 October 2008
Cited by 50 | PDF Full-text (886 KB) | HTML Full-text | XML Full-text
Abstract
Proanthocyanidins (PAs), also known as condensed tannins, are a group of polyphenolic secondary metabolites synthesized in plants as oligomers or polymers of flavan-3-ol units via the flavonoid pathway. Due to their structural complexity and varied composition, only in the recent years has [...] Read more.
Proanthocyanidins (PAs), also known as condensed tannins, are a group of polyphenolic secondary metabolites synthesized in plants as oligomers or polymers of flavan-3-ol units via the flavonoid pathway. Due to their structural complexity and varied composition, only in the recent years has the study on the biosynthesis and regulation of PAs in plants taken off, although some details of the synthetic mechanism remain unclear. This paper aims to summarize the status of research on the structures of PAs in plants, the genes encoding key enzymes of biosynthetic pathway, the transport factors, the transcriptional regulation of PA biosynthesis and the genetic manipulation of PAs. The problems of this field were also discussed, including the nature of the final “enzyme” which catalyzes the polymerization reaction of PAs and the possible mechanism of how the elementary units of flavanols are assembled in vivo. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
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