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Molecules, Volume 13, Issue 6 (June 2008), Pages 1219-1440

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Research

Jump to: Review

Open AccessArticle Identification of Minor Secondary Metabolites from the Latex of Croton lechleri (Muell-Arg) and Evaluation of Their Antioxidant Activity
Molecules 2008, 13(6), 1219-1229; doi:10.3390/molecules13061219
Received: 6 May 2008 / Accepted: 29 May 2008 / Published: 1 June 2008
Cited by 20 | PDF Full-text (130 KB) | HTML Full-text | XML Full-text
Abstract
Dragon’s blood (Sangre de drago), a viscous red sap derived from Croton lechleri Muell-Arg (Euphorbiaceae), is extensively used by indigenous cultures of the Amazonian basin for its wound healing properties. The aim of this study was to identify the minor secondary metabolites and
[...] Read more.
Dragon’s blood (Sangre de drago), a viscous red sap derived from Croton lechleri Muell-Arg (Euphorbiaceae), is extensively used by indigenous cultures of the Amazonian basin for its wound healing properties. The aim of this study was to identify the minor secondary metabolites and test the antioxidant activity of this sustance. A bioguided fractionation of the n-hexane, chloroform, n-butanol, and aqueous extracts led to the isolation of 15 compounds: three megastigmanes, four flavan-3-ols, three phenylpropanoids, three lignans, a clerodane, and the alkaloid taspine. In addition to these known molecules, six compounds were isolated and identified for the first time in the latex: blumenol B, blumenol C, 4,5-dihydroblumenol A, erythro-guaiacyl-glyceryl-β-O-4’- dihydroconiferyl ether, 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-propane-1,3-diol and floribundic acid glucoside. Combinations of spectroscopic methods (1H-, 13C- NMR and 2D-NMR experiments), ESI-MS, and literature comparisons were used for compound identification. In vitro antioxidant activities were assessed by DPPH, total antioxidant capacity and lipid peroxidation assays. Flavan-3-ols derivatives (as major phenolic compounds in the latex) exhibited the highest antioxidant activity. Full article
Open AccessArticle Conversion of Oximes to Carbonyl Compounds by Triscetylpyridinium Tetrakis(oxodiperoxotungsto) Phosphate (PCWP)-mediated Oxidation with Hydrogen Peroxide
Molecules 2008, 13(6), 1230-1237; doi:10.3390/molecules13061230
Received: 29 April 2008 / Revised: 12 May 2008 / Accepted: 15 May 2008 / Published: 1 June 2008
Cited by 11 | PDF Full-text (52 KB) | HTML Full-text | XML Full-text
Abstract
Aromatic and aliphatic oximes have been deoximated in chloroform-water to the corresponding aldehydes with dilute hydrogen peroxide and triscetylpyridinium tetrakis (oxodiperoxotungsto) phosphate as catalyst. The presence of dipolarophiles in the reaction mixtures allows a competitive reaction that converts oximes into isoxazole and isoxazoline
[...] Read more.
Aromatic and aliphatic oximes have been deoximated in chloroform-water to the corresponding aldehydes with dilute hydrogen peroxide and triscetylpyridinium tetrakis (oxodiperoxotungsto) phosphate as catalyst. The presence of dipolarophiles in the reaction mixtures allows a competitive reaction that converts oximes into isoxazole and isoxazoline derivatives via the intermediate formation of nitrile oxide species. Full article
Open AccessArticle Anthocyanin Characterization of Pilot Plant Water Extracts of Delonix regia Flowers
Molecules 2008, 13(6), 1238-1245; doi:10.3390/molecules13061238
Received: 5 May 2008 / Revised: 29 May 2008 / Accepted: 29 May 2008 / Published: 1 June 2008
Cited by 15 | PDF Full-text (176 KB) | HTML Full-text | XML Full-text
Abstract
Following the development of new applications of pilot plant scale extraction and formulation processes for natural active bioproducts obtained from various underutilized tropical plants and herbs, we have manufactured water-extracts from Delonix regia flowers, grown in Ivory Coast. These extracts, which contain polyphenols,
[...] Read more.
Following the development of new applications of pilot plant scale extraction and formulation processes for natural active bioproducts obtained from various underutilized tropical plants and herbs, we have manufactured water-extracts from Delonix regia flowers, grown in Ivory Coast. These extracts, which contain polyphenols, are traditionally home made and used as healthy bioproducts. They are reddish-coloured due to the presence of anthocyanins. The three major anthocyanins in these extracts have been characterized. The molecular structures were confirmed by LC-SM analysis. Amongst them, two are described for the first time in Delonix regia. Full article
Open AccessArticle Density Functional Theory Study of the Trans-Trans-Cis (TTC)→Trans-Trans-Trans (TTT) Isomerization of a Photochromic Spiropyran Merocyanine
Molecules 2008, 13(6), 1246-1252; doi:10.3390/molecules13061246
Received: 25 April 2008 / Revised: 26 May 2008 / Accepted: 28 May 2008 / Published: 3 June 2008
Cited by 7 | PDF Full-text (178 KB) | HTML Full-text | XML Full-text
Abstract
Density Functional Theory (DFT) calculations have been performed on the TTC→TTT isomerization reaction of the open forms of the 1',3'-dihydro-8-bromo-6-nitro- 1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-(2H)indole (8-Br-6-nitro-BIPS) system. The calculations were carried out in vacuo and in methylene chloride solution at different temperatures. Results are compared with the
[...] Read more.
Density Functional Theory (DFT) calculations have been performed on the TTC→TTT isomerization reaction of the open forms of the 1',3'-dihydro-8-bromo-6-nitro- 1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-(2H)indole (8-Br-6-nitro-BIPS) system. The calculations were carried out in vacuo and in methylene chloride solution at different temperatures. Results are compared with the available experimental values of free energy difference and activation energy in solution. Full article
(This article belongs to the Special Issue Spiro Compounds)
Open AccessArticle Diterpenes from the Brown Alga Dictyota crenulata
Molecules 2008, 13(6), 1253-1262; doi:10.3390/molecules13061253
Received: 30 April 2008 / Revised: 2 June 2008 / Accepted: 3 June 2008 / Published: 4 June 2008
Cited by 12 | PDF Full-text (316 KB) | HTML Full-text | XML Full-text
Abstract
The crude extract of the Brazilian brown alga Dictyota crenulata was analyzed by NMR spectroscopy and HRGC-MS techniques. Seven diterpenes were identified: pachydictyol A, dictyodial, 4β-hydroxydictyodial A, 4β-acetoxydictyodial A, isopachydictyol A, dictyol C and dictyotadiol. Xeniane diterpenes have previously been found in D.
[...] Read more.
The crude extract of the Brazilian brown alga Dictyota crenulata was analyzed by NMR spectroscopy and HRGC-MS techniques. Seven diterpenes were identified: pachydictyol A, dictyodial, 4β-hydroxydictyodial A, 4β-acetoxydictyodial A, isopachydictyol A, dictyol C and dictyotadiol. Xeniane diterpenes have previously been found in D. crenulata from the Pacific Ocean. The results characterize D. crenulata as a species that provides prenylated guaiane (group I) and xeniane diterpenes (group III), thus making it a new source of potential antiviral products. Full article
Open AccessArticle Preparation of Chitosan from Brine Shrimp (Artemia urmiana) Cyst Shells and Effects of Different Chemical Processing Sequences on the Physicochemical and Functional Properties of the Product
Molecules 2008, 13(6), 1263-1274; doi:10.3390/molecules13061263
Received: 24 April 2008 / Revised: 8 May 2008 / Accepted: 9 May 2008 / Published: 6 June 2008
Cited by 38 | PDF Full-text (147 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan (CS) was prepared from Artemia urmiana cyst shells using the same chemical process as described for the other crustacean species, with minor adjustments in the treatment conditions. The influence of modifications of the CS production process on the physiochemical and functional properties
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Chitosan (CS) was prepared from Artemia urmiana cyst shells using the same chemical process as described for the other crustacean species, with minor adjustments in the treatment conditions. The influence of modifications of the CS production process on the physiochemical and functional properties of the CS obtained was examined. The study results indicate that Artemia urmiana cyst shells are a rich source of chitin as 29.3-34.5% of the shell’s dry weight consisted of this material. Compared to crab CS (selected as an example of CS from a different crustacean source) Artemia CS exhibited a medium molecular weight (4.5-5.7 ×105 Da), lower degree of deacetylation (67-74%) and lower viscosity (29-91 centiposes). The physicochemical characteristics (e.g., ash, nitrogen and molecular weight) and functional properties (e.g., water binding capacity and antibacterial activity) of the prepared Artemia CSs were enhanced, compared to control and commercial samples, by varying the processing step sequence. Full article
Open AccessCommunication A New Sesquiterpenoid Hydroquinone from the Marine Sponge Dysidea arenaria
Molecules 2008, 13(6), 1275-1281; doi:10.3390/molecules13061275
Received: 23 May 2008 / Revised: 5 June 2008 / Accepted: 5 June 2008 / Published: 6 June 2008
Cited by 9 | PDF Full-text (133 KB) | HTML Full-text | XML Full-text
Abstract
Detailed chemical investigation of the South China sponge Dysidea arenaria resulted in the isolation of a new sesquiterpenoid hydroquinone, 19-hydroxypolyfibrospongol B (1), along with five known compounds: polyfibrospongol B (2), isosemnonorthoquinone (3), ilimaquinone (4), smenospongine (5) and smenotronic acid (6). The structures were
[...] Read more.
Detailed chemical investigation of the South China sponge Dysidea arenaria resulted in the isolation of a new sesquiterpenoid hydroquinone, 19-hydroxypolyfibrospongol B (1), along with five known compounds: polyfibrospongol B (2), isosemnonorthoquinone (3), ilimaquinone (4), smenospongine (5) and smenotronic acid (6). The structures were determined by extensive spectroscopic analysis. The in vitro anti- HIV activity on HIV-1 RT was evaluated. Compounds 3 -6 displayed moderate inhibitory activity, with IC50 values of 239.7, 16.4, 176.1, and 130.4 μM, respectively, while 1 and 2 were found to be inactive against the same biological target. Full article
Open AccessCommunication Unusual Regioselectivity in the Opening of Epoxides by Carboxylic Acid Enediolates
Molecules 2008, 13(6), 1303-1311; doi:10.3390/molecules13061303
Received: 29 May 2008 / Revised: 5 June 2008 / Accepted: 6 June 2008 / Published: 9 June 2008
Cited by 5 | PDF Full-text (139 KB) | HTML Full-text | XML Full-text
Abstract
Addition of carboxylic acid dianions appears to be a potential alternative to the use of aluminium enolates for nucleophilic ring opening of epoxides. These conditions require the use of a sub-stoichiometric amount of amine (10% mol) for dianion generation and the previous activation
[...] Read more.
Addition of carboxylic acid dianions appears to be a potential alternative to the use of aluminium enolates for nucleophilic ring opening of epoxides. These conditions require the use of a sub-stoichiometric amount of amine (10% mol) for dianion generation and the previous activation of the epoxide with LiCl. Yields are good, with high regioselectivity, but the use of styrene oxide led, unexpectedly, to a mixture resulting from the attack on both the primary and secondary carbon atoms. Generally, a low diastereoselectivity is seen on attack at the primary center, however only one diastereoisomer was obtained from attack to the secondary carbon of the styrene oxide. Full article
Open AccessArticle Efficient and Simple Synthesis of 6-Aryl-1,4-dimethyl-9H-carbazoles
Molecules 2008, 13(6), 1312-1320; doi:10.3390/molecules13061312
Received: 3 June 2008 / Revised: 10 June 2008 / Accepted: 10 June 2008 / Published: 11 June 2008
Cited by 21 | PDF Full-text (63 KB) | HTML Full-text | XML Full-text
Abstract A synthetic method for the preparation of 6-aryl-1,4-dimethyl-9H-carbazoles involving a palladium catalyzed coupling reaction of 1,4-dimethyl-9H-carbazole-6-boronic acids and (hetero)aryl halides is described. Full article
Open AccessArticle Do Cultivar, Geographical Location and Crop Season Influence Phenolic Profile of Walnut Leaves?
Molecules 2008, 13(6), 1321-1332; doi:10.3390/molecules13061321
Received: 7 May 2008 / Revised: 7 June 2008 / Accepted: 8 June 2008 / Published: 12 June 2008
Cited by 18 | PDF Full-text (147 KB) | HTML Full-text | XML Full-text
Abstract
Walnut leaves from nine different cultivars (Arco, Franquette, Hartley, Lara, Marbot, Mayette, Meylannaise, Parisienne and Rego) were studied for their phenolic compounds. Samples were harvested along three consecutive years, at two different geographical locations, in order to evaluate if significant differences in the
[...] Read more.
Walnut leaves from nine different cultivars (Arco, Franquette, Hartley, Lara, Marbot, Mayette, Meylannaise, Parisienne and Rego) were studied for their phenolic compounds. Samples were harvested along three consecutive years, at two different geographical locations, in order to evaluate if significant differences in the phenolics composition can be related with genetic, climatic or geographical factors. Nine compounds (3-caffeoylquinic, 3-p-coumaroylquinic and 4-p-coumaroylquinic acids, quercetin 3- galactoside, quercetin 3-arabinoside, quercetin 3-xyloside, quercetin 3-rhamnoside, a quercetin 3-pentoside derivative and a kaempferol 3-pentoside derivative) were quantified using an HPLC-DAD methodology. The qualitative profiles were identical for all samples, but differences were observed in terms of individual compounds’ contents. Multivariate statistical analysis was carried out, showing that significant differences exist among production years, which can be related to climatic reasons. Full article
Open AccessArticle Characterization of Aroma Active Compounds in Fruit Juice and Peel Oil of Jinchen Sweet Orange Fruit (Citrus sinensis (L.) Osbeck) by GC-MS and GC-O
Molecules 2008, 13(6), 1333-1344; doi:10.3390/molecules13061333
Received: 20 April 2008 / Revised: 19 May 2008 / Accepted: 19 May 2008 / Published: 12 June 2008
Cited by 55 | PDF Full-text (240 KB) | HTML Full-text | XML Full-text
Abstract
Gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel
[...] Read more.
Gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel oil, respectively. GC-O was performed to study the aromatic profile of Jinchen fruit juice and peel oil. A total of 41 components appeared to contribute to the aroma of fruit juice and peel oil. Twelve components were the odorants perceived in both samples. The aromatic compositions of fruit juice were more complex than that of peel oil. Ethyl butanoate, β-myrcene, octanal, linalool, α-pinene, and decanal were found to be responsible for the aromatic notes in fruit juice and peel oil. Nineteen components have been perceived only in the juice and ten compounds were described as aromatic components of only the peel oil by the panelists. These differences lead to the different overall aroma between fruit juice and peel oil. Full article
Open AccessArticle Ring Contracting Sulfur Extrusion from Oxidized Phenothiazine Ring Systems
Molecules 2008, 13(6), 1345-1352; doi:10.3390/molecules13061345
Received: 1 June 2008 / Revised: 10 June 2008 / Accepted: 10 June 2008 / Published: 12 June 2008
Cited by 5 | PDF Full-text (96 KB) | HTML Full-text | XML Full-text
Abstract
Lithium, used in conjunction with sodium metal, produces a high yield of carbazole when reacted with phenothiazine-5-oxide or phenothiazine-5,5-dioxide. A high yield of 9-ethylcarbazole is also produced when these reagents react with 10-ethylphenothiazine, 10-ethylphenothiazine-5-oxide, and 10-ethylphenothiazine-5,5-dioxide. Degassed Raney nickel produces carbazole in high
[...] Read more.
Lithium, used in conjunction with sodium metal, produces a high yield of carbazole when reacted with phenothiazine-5-oxide or phenothiazine-5,5-dioxide. A high yield of 9-ethylcarbazole is also produced when these reagents react with 10-ethylphenothiazine, 10-ethylphenothiazine-5-oxide, and 10-ethylphenothiazine-5,5-dioxide. Degassed Raney nickel produces carbazole in high yield when reacted with phenothiazine and phenothiazine-5-oxide. A moderate yield of 9-ethylcarbazole is produced when n-butyllithium is reacted with 10-ethylphenothiazine-5-oxide. Full article
Open AccessArticle Syntheses of Diheterocyclic Compounds Based on 2-Thioacetohydrazide-5,7-dimethyl-1,2,4-triazolo[1,5-a]- pyrimidine
Molecules 2008, 13(6), 1353-1360; doi:10.3390/molecules13061353
Received: 6 May 2008 / Revised: 26 May 2008 / Accepted: 26 May 2008 / Published: 13 June 2008
Cited by 2 | PDF Full-text (119 KB) | HTML Full-text | XML Full-text
Abstract The syntheses of some diheterocyclic compounds from 2-thioacetohydrazide- 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine (1) are described. Compound 1 can be converted into triazoles, 1,3,4-oxadiazoles, and 1,3,4-thiadiazoles. The structures of the intermediates and the target compounds were confirmed by 1H-NMR, MS and elemental analyses. Full article
Open AccessArticle Camptothecinoids from the seeds of Taiwanese Nothapodytes foetida
Molecules 2008, 13(6), 1361-1371; doi:10.3390/molecules13061361
Received: 9 May 2008 / Revised: 3 June 2008 / Accepted: 3 June 2008 / Published: 16 June 2008
Cited by 12 | PDF Full-text (295 KB) | HTML Full-text | XML Full-text
Abstract
Two new alkaloids, 9-methoxy-18,19-dehydrocamptothecin (1) and 5- hydroxymappicine-20-O-β-glucopyranoside (2a/2b as a racemic mixture), together with nine known compounds: camptothecin (3), 9-methoxy-camptothecin (4), 5-hydroxycamptothecin (5a/5b racemic mixture), 5-hydroxy-9-methoxycamptothecin (6a/6b racemic mixture), diosmetin (7), apigenin (8), apigenin-7-O-glucopyranoside (9), rosin (cinnamyl- O-β-D-glucopyranoside) (10) and amarantholidoside IV
[...] Read more.
Two new alkaloids, 9-methoxy-18,19-dehydrocamptothecin (1) and 5- hydroxymappicine-20-O-β-glucopyranoside (2a/2b as a racemic mixture), together with nine known compounds: camptothecin (3), 9-methoxy-camptothecin (4), 5-hydroxycamptothecin (5a/5b racemic mixture), 5-hydroxy-9-methoxycamptothecin (6a/6b racemic mixture), diosmetin (7), apigenin (8), apigenin-7-O-glucopyranoside (9), rosin (cinnamyl- O-β-D-glucopyranoside) (10) and amarantholidoside IV (11) were isolated from the immature seeds of Nothapodytes foetida (Wight) Sleumer. The structures were elucidated by spectroscopic analyses. In the present research, compounds 1, 3, 4, 5a/5b and 6a/6b, also showed in vitro cytotoxicity against six cancer cell lines (HepG2, Hep3B, MDA-MB- 231, MCF-7, A549, and Ca9-22). Among them, compound 1 exhibited significant cytotoxicity against these cancer cell lines, with IC50 of 0.24-6.57 μM. Furthermore, HPLC profiles were developed for qualitative and quantitative analysis of these active constituents in different parts of this plant, including mature and immature seeds, leaves, stems and roots. The results revealed that compounds 3 and 4 have the highest concentrations, which are found in the roots part of the plant. Full article
Open AccessArticle Fractionated Marine Invertebrate Extract Libraries for Drug Discovery
Molecules 2008, 13(6), 1372-1383; doi:10.3390/molecules13061372
Received: 3 June 2008 / Revised: 18 June 2008 / Accepted: 18 June 2008 / Published: 19 June 2008
Cited by 35 | PDF Full-text (283 KB) | HTML Full-text | XML Full-text
Abstract
The high-throughput screening and drug discovery paradigm has necessitated a change in preparation of natural product samples for screening programs. In an attempt to improve the quality of marine natural products samples for screening, several fractionation strategies were investigated. The final method used
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The high-throughput screening and drug discovery paradigm has necessitated a change in preparation of natural product samples for screening programs. In an attempt to improve the quality of marine natural products samples for screening, several fractionation strategies were investigated. The final method used HP20SS as a solid support to effectively desalt extracts and fractionate the organic components. Additionally, methods to integrate an automated LCMS fractionation approach to shorten discovery time lines have been implemented. Full article
(This article belongs to the Special Issue Natural Product Pre-fractionation)
Open AccessCommunication Two New Flavonol Glycosides from Sarcopyramis bodinieri var. delicate
Molecules 2008, 13(6), 1399-1405; doi:10.3390/molecules13061399
Received: 4 June 2008 / Revised: 17 June 2008 / Accepted: 17 June 2008 / Published: 19 June 2008
Cited by 13 | PDF Full-text (151 KB) | HTML Full-text | XML Full-text
Abstract
Detailed chemical investigation of the herb Sarcopyramis bodinieri var. delicate resulted in the isolation of two new flavonol glycosides, namely, isorhamnetin-3-O-(6′′-OE- feruloyl)-β-D-glucopyranoside (1) and isorhamnetin-3-O-(6′′-O-E-feruloyl)-β-Dgalactopyranoside (2). In addition, four known compounds, quercetin-3-O-(6′′-acetyl)-β-Dglucopyranoside (3), isorhamnetin-3-O-(6′′-acetyl)-β-D-glucopyranoside (4), quercetin-3- O-(6′′-O-E-p-coumaroyl)-β-D-glucopyranoside (5), and isorhamnetin-3-O-(6′′-O-E-pcoumaroyl)- β-D-glucopyranoside (6) were
[...] Read more.
Detailed chemical investigation of the herb Sarcopyramis bodinieri var. delicate resulted in the isolation of two new flavonol glycosides, namely, isorhamnetin-3-O-(6′′-OE- feruloyl)-β-D-glucopyranoside (1) and isorhamnetin-3-O-(6′′-O-E-feruloyl)-β-Dgalactopyranoside (2). In addition, four known compounds, quercetin-3-O-(6′′-acetyl)-β-Dglucopyranoside (3), isorhamnetin-3-O-(6′′-acetyl)-β-D-glucopyranoside (4), quercetin-3- O-(6′′-O-E-p-coumaroyl)-β-D-glucopyranoside (5), and isorhamnetin-3-O-(6′′-O-E-pcoumaroyl)- β-D-glucopyranoside (6) were obtained. The structures of the new isolates were determined by extensive spectroscopic analysis. Full article
Open AccessArticle Pre-fractionated Microbial Samples – The Second Generation Natural Products Library at Wyeth
Molecules 2008, 13(6), 1406-1426; doi:10.3390/molecules13061406
Received: 30 May 2008 / Accepted: 16 June 2008 / Published: 20 June 2008
Cited by 28 | PDF Full-text (487 KB) | HTML Full-text | XML Full-text
Abstract
From the beginning of the antibiotic era in the 1940s to the present, Wyeth has sustained an active research program in the area of natural products discovery. This program has continually evolved through the years in order to best align with the “current”
[...] Read more.
From the beginning of the antibiotic era in the 1940s to the present, Wyeth has sustained an active research program in the area of natural products discovery. This program has continually evolved through the years in order to best align with the “current” drug discovery paradigm in the pharmaceutical industry. The introduction of highthroughput screening and the miniaturization of assays have created a need to optimize natural product samples to better suit these new technologies. Furthermore, natural product programs are faced with an ever shortening time period from hit detection to lead characterization. To address these issues, Wyeth has created a pre-fractionated natural products library using reversed-phase HPLC to complement their existing library of crude extracts. The details of the pre-fractionated library and a cost-benefit analysis will be presented in this review. Full article
(This article belongs to the Special Issue Natural Product Pre-fractionation)
Open AccessArticle Design, Synthesis, and Antitumor Activities of Some Novel Substituted 1,2,3-Benzotriazines
Molecules 2008, 13(6), 1427-1440; doi:10.3390/molecules13061427
Received: 2 June 2008 / Revised: 22 June 1995 / Accepted: 23 June 2008 / Published: 24 June 2008
Cited by 7 | PDF Full-text (164 KB) | HTML Full-text | XML Full-text
Abstract
A series of novel substituted 1,2,3-benzotriazines based on the structures of vatalanib succinate (PTK787) and vandetanib (ZD6474) were designed and synthesized. The antiproliferative effects of these compounds were tested on microvascular endothelial cells (MVECs) using the MTT assay. Introduction of a methoxy and
[...] Read more.
A series of novel substituted 1,2,3-benzotriazines based on the structures of vatalanib succinate (PTK787) and vandetanib (ZD6474) were designed and synthesized. The antiproliferative effects of these compounds were tested on microvascular endothelial cells (MVECs) using the MTT assay. Introduction of a methoxy and a 3-chloropropoxy group into the 1,2,3-benzotriazines increased the antiproliferative effects. 4-(3-Chloro-4- fluoroanilino)-7-(3-chloropropoxy)-6-methoxy-1,2,3-benzotriazine (8m) was the most effective compound. It was 4-10 fold more potent than PTK787 in inhibiting the growth of T47D breast cancer cells, DU145 and PC-3 prostate cancer cells, LL/2 murine Lewis lung cancer cells and B16F0 melanoma cells. Full article

Review

Jump to: Research

Open AccessReview Stable Spirocyclic Meisenheimer Complexes
Molecules 2008, 13(6), 1282-1302; doi:10.3390/molecules13061282
Received: 15 May 2008 / Revised: 6 June 2008 / Accepted: 6 June 2008 / Published: 9 June 2008
Cited by 12 | PDF Full-text (168 KB) | HTML Full-text | XML Full-text
Abstract
Meisenheimer complexes are important intermediates in Nucleophilic Aromatic Substitution Reactions (SNAr). They are formed by the addition of electron rich species to polynitro aromatic compounds or aromatic compounds with strong electron withdrawing groups. It is possible to distinguish two types of
[...] Read more.
Meisenheimer complexes are important intermediates in Nucleophilic Aromatic Substitution Reactions (SNAr). They are formed by the addition of electron rich species to polynitro aromatic compounds or aromatic compounds with strong electron withdrawing groups. It is possible to distinguish two types of Meisenheimer or σ-complexes, the σHcomplex or σX-complex (also named ipso), depending on the aromatic ring position attacked by the nucleophile (a non-substituted or substituted one, respectively). Special examples of σX- or ipso-complexes are formed through intermediate spiro adducts, via intramolecular SNAr. Some of these spirocyclic Meisenheimer complexes, a type of σXcomplex, are exceptionally stable in solution and/or as solids. They can be isolated and characterized using X-ray, and various spectroscopic techniques such as NMR, UV-Vis, IR, and fluorescence. A few of these stable spirocyclic Meisenheimer complexes are zwitterionic and exhibit interesting photophysical and redox properties. We will review recent advances, synthesis and potential applications of these stable spirocyclic Meisenheimer complexes. Full article
(This article belongs to the Special Issue Spiro Compounds)
Open AccessReview Tomato Derived Polysaccharides for Biotechnological Applications: Chemical and Biological Approaches
Molecules 2008, 13(6), 1384-1398; doi:10.3390/molecules13061384
Received: 30 May 2008 / Revised: 17 June 2008 / Accepted: 17 June 2008 / Published: 19 June 2008
Cited by 8 | PDF Full-text (412 KB) | HTML Full-text | XML Full-text
Abstract
Recent studies concerning the isolation and purification of exopolysaccharides from suspension-cultured tomato (Lycopersicon esculentum L. var. San Marzano) cells and the description of a simple, rapid and low environmental impact method with for obtaining polysaccharides from solid tomato-processing industry wastes are reported.
[...] Read more.
Recent studies concerning the isolation and purification of exopolysaccharides from suspension-cultured tomato (Lycopersicon esculentum L. var. San Marzano) cells and the description of a simple, rapid and low environmental impact method with for obtaining polysaccharides from solid tomato-processing industry wastes are reported. Their chemical composition, rheological properties and partial primary structure were determined on the basis of spectroscopic analyses (UV, IR, GC-MS, 1H-, 13C-NMR). Moreover, the anticytotoxic activities of exopolysaccharides obtained from cultured tomato cells were tested in a brine shrimp bioassay and the preparation of biodegradable film by chemical processing of polysaccharides from solid tomato industry waste was also reported. Full article

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