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From the roots of the plant Tephrosia aequilata Baker, five flavonoids were isolated of which, 3,4:8,9-dimethylenedioxypterocarpan is reported for the first time. Its structure and those of the already known flavonoids were established by physical and spectroscopic analysis. Application of 2D NMR techniques was useful for complete characterization of the new pterocarpan as well as the other known flavonoids.
Four iridoid glucosides, three of which are dimeric were isolated from the methanol extract of roots of Vietnamese Paederia scandens (Lour) Merrill together with the five known glucosides, paederoside, asperuloside, paederosidic acid, asperulosidic acid and geniposide. Seven sulfur-containing iridoid glucosides were also isolated. The structures of the iridoid glucosides were determined by a combination of high-resolution NMR, MS, IR and UV spectra, and chemical reaction such as acetylation.
A new iridoid glucoside dimer, coelobillardin (1), was isolated from the aerial parts of Coelospermum billardieri. Its structure has been elucidated on the basis of MS and NMR data. From a biogenetic point of view, this compound, which includes a cyclobutane basic core, should be considered as a [2+2] dimerization product of (E)-10-(4-hydroxycinnamoyloxy)loganin, which is the major iridoid isolated from the plant.
From the methanolic extract of the seeds of the Brazilian Joannesia princeps 3,3'-bisdemethylpinoresinol and six new sesquineolignans were isolated besides the known neolignans americanol A, isoamericanol A and isoamericanin A which were found to be the major constituents. A method was developed to distinguish americanol- from isoamericanol-type compounds spectroscopically.
From the rhizomes of Polygonatum alte-lobatum, two new homologous series of 1,4-benzoquinones, polygonaquinones A and B, a novel homoisoflavanone, a new gentrogenin glycoside and 13 known compounds were isolated and characterized. The structures of the new compounds were determined as two homologous series of three 2,5-dihydroxy-3-methyl-6-alkyl-1,4-benzoquinones and three 2-hydroxy-3-methyl-6-alkyl-1,4-benzoquinones, with chain lengths C21 to C23, and 4',5,7-trihydroxy-6,8-dimethylhomoisoflavanone and gentrogenin 3-O-beta-D-glucopyranosyl(1-->2)-[beta-D-xylopyranosyl(1-->3)] -beta-D-glucopyranosyl(1-->4)-beta-D-galactopyranoside.
Two new alkaloids, 9-carbethoxy-3-methylcarbazole and 9-formyl-3-methylcarbazole, and a known metabolite, 3-methyl-carbazole were isolated from the roots of Murraya koenigii. All three compounds were identified by detailed spectral analyses including 2D NMR studies and their structures confirmed by synthesis. Of the two new metabolites, the 9-formyl compound displayed weak cytotoxicity against both mouse melanoma B16 and adriamycin-resistant P388 mouse leukemia cell lines.
From the hexane extract of berries of Juniperus excelsa, one new and four known diterpenes were isolated besides a known sesquiterpene. The structures of the known diterpenes were identified as isopimaric, isocommunic, (-)ent-trans communic and sandracopimaric acids, along with the sesquiterpene 4a-hydroxycedrol and the new compound which was elucidated as 3 alpha-acetoxylabda-8(17),13(16),14-trien-19-oic acid (juniperexcelsic acid). Cytotoxic activity of the hexane extract was investigated against a panel of cell line and found highly active against LNCaP, KB-V (+VLB) and KB-V (-VLB) cell lines. Furthermore, the hexane and methanol extracts, and the new compound were found to be moderately active against Mycobacterium tuberculosis.
From the dried roots of Cephaelis acuminata, five ipecac alkaloids, neocephaeline, 7'-O-demethylcephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)cephaeline and 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)neocephaeline, were isolated, along with emetine, cephaeline, psychotrine, protoemetine, 9-demethylprotoemetinol and isocephaeline. Structures were determined by spectroscopic and chemical means.
The structure of a new type of sesterterpenoid, designated as alborosin, isolated from Gentianella alborosea, has been deduced from a spectroscopic investigation.
A p-hydroxyacetophenone-like derivative, (+)-gynunone, and a chromane, together with six known compounds were isolated from the CHCl3 fraction of the roots of Gynura elliptica. Their structures were determined by means of spectral analyses. Among the isolates, 6-acetyl-2,2-dimethylchroman-4-one and vanillin showed anti-platelet aggregation activity induced by arachidonic acid in vitro.
Two new polyhydroxysteroids isihippurols A (1) and B (2) were isolated from the MeOH extract of the gorgonian Isis hippuris in addition to nine known steroids namely gorgosterol, 3alpha-acetoxy-24-methyl 11beta,18; 18,20beta; 22,25-triepoxy-5alpha-furostane, hippurin-1, 22-epi-hippuristanol, 22-epi-hippurin-1, 3-acetyl-2-deacetyl-22-epi-hippurin-1, 2-deacetylhippurin-1, 3beta, 7alpha, 11alpha-trihydroxygorgost-5-ene-12beta-acetate and 2-deacetyl-22-epi-hippurin-1. The structures of 1 and 2 have been determined as 1alpha, 3beta, 5alpha, 6beta, 11alpha-pentahydroxygorgosta-12beta-monoacetate and 1alpha, 3beta, 11alpha-trihydroxygorgosta-5alpha, 6alpha-epoxy-12beta-monoacetate respectively by spectral analysis and chemical correlation.
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3-Oxo-17 alpha-pregna-4,6-diene-21,17-carbolactone (canrenone, II) is produced from the potassium salt of 17-hydroxy-3-oxo-17 alpha-pregna-4,6-diene-21-carboxylic acid (I) by acid catalyzed lactonization. II reacts with acetic anhydride/nitric acid to give one main product (III) and some minor products. The structure of III was determined by chemical and spectral analysis to the 4-nitro derivative of canrenone. This result is in contrast to the known reactions of II with most other reagents that were found to add at delta(6), and also in contrast to the reactions of acetic anhydride/nitric acid with alkenes. Electrophilic substitution at the ambident C4 is discussed as the reaction path. The 4-nitro group enhances the inhibitory activity of II against Na+/K(+)-ATPase, the target enzyme of the cardioactive digitalis glycosides, which appears to indicate increased cardioactivity.
A Mycobacterium sp., strain KR2 which was able to utilise pyrene as sole source of carbon and energy was isolated from a polycyclic aromatic hydrocarbon (PAH) contaminated soil originating from the area of a former gaswork plant. The isolate metabolised up to 60% of the pyrene added (0.5 mg/mL) within 8 days at 20 degrees C. Cis-4,5-pyrene dihydrodiol, 4,5-phenanthrene dicarboxylic acid, 1-hydroxy-2-naphthoic acid, 2-carboxybenzaldehyde, phthalic acid, and protocatechuic acid were identified as degradation products. Based on these findings a degradation pathway for pyrene is suggested which is in good accordance with the data published so far on bacterial pyrene metabolism.
Plastics destined for facilities holding aquatic fauna, such as aquaculture and aquatic toxicology laboratories, were studied. The plastics were extracted with dichloromethane. The fungicide 10,10'-oxybisphenoxarsine (OBPA) was detected by silver nitrate after cleanup on a silica cartridge and TLC in petroleum ether-diethyl ether-acetic acid 80:20:1. The flame retardant decabromodiphenyl ether (DBDPO) was crystallized from dichloromethane and confirmed by IR spectrum. A UV-spectrophotometric method is suggested for the estimation of the leaching potential of additives from plastics.
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Explore the source record for details and available documents.