29 research outputs found
Cyanolipids from Sapindus saponaria L. seeds oil
The chemical composition of the oil extracted from the seeds of Sapindus saponaria L., (Sapindaceae), was investigated. Cyanolipids constituted 5% hexane extract of the seeds, whereas triacylglycerols (TAG) accounted for 90%. The oil contains type III cyanolipids (CL) 1-cyano-2-hydroxymethylprop-1-en-3-ol-diesters. Structural investigation of the oil components was accomplished by chemical, chromatographic (TLC, CC, GC-MS), and spectroscopic (IR, NMR) means. GC-MS analysis showed that fatty acids were dominant in the CL components of the oil from S. saponaria L., with cis-11-eicosenoic acid, cis-11-octadecenoic acid and eicosanoic acid as the only esterified fatty acyl chains respectively. This being the first report of this kind of natural products (CL), located in the seeds of this plant
Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions
Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction
Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions
Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-ÎČ-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction
Sorção e persistĂȘncia da sorgoleona em um Latossolo Vermelho-Amarelo Sorption and persistence of sorgoleone in Red-Yellow Latosol
<abstract language="eng">The root exudates produced by sorghum contain a biologically active constituent known as sorgoleone. The behavior of sorgoleone in a Red-Yellow Latosol was studied. The sorption model of sorgoleone in soil was better adjusted to the Freundlich equation, through the coefficients Kf (capacity of sorption) and 1/n (linearity of the isotherm). The persistence of sorgoleone in soil and its possible degradation were also evaluated by monitoring their residues in the soil along the time. Recovery rate of sorgoleone from the soil reached 93% after 24h. It was verified that sorgoleone is strongly sorbed in the soil and its half-life is 10 days, under the experimental conditions. The presence of sorgoleone or its metabolites was not detected in the soil after 60 days
Computation and structural elucidation of compounds formed via epoxide alcoholysis
Isobenzofuranones are known for their wide range of biological activities such as fungicide, insecticide, and anticancer. The search for novel bioactive compounds was performed by reaction of epoxide 2 with methanol, ethanol, propanâ1âol, propanâ2âol, and butanâ1âol.
The mechanism for the stereoselective and stereospecific epoxide opening with methanol was reasoned by calculating the transition states for the two putative structures (rac)â3a and (rac)â3b. The compound (rac)â3a is the kinetic product as inferred from the lower energies of its transition state (TS1). The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts for these two candidate structures were calculated and compared with the experimental data using mean absolute error (MAE) and DP4 analyses. Therefore, the relative stereochemistry of (rac)â3a was established by the mechanism, MAE, and DP4 approaches. The hydroxyl group was acetylated to surpass the problem of signal overlapping of H5 and H6 in the 1H NMR. The relative stereochemistry of the corresponding ester determined by NMR interpretation was in agreement with the structure of (rac)â3a
Hederagenin as a triterpene template for the development of new antitumor compounds
In this study, a series of novel C-28 esters and amides derivatives of hederagenin (He) were designed and synthesized in attempt to develop potent antitumor agents. Their structures were confirmed by MS, IR, 1H NMR and ^13C NMR spectroscopic analyses and their cytotoxic activities were screened in SRB assays using a panel of six human cancer cell lines. Although most of the compounds displayed moderate to high levels of cytotoxic activity they were all more potent than the natural product He. The most active compounds had either an ethylpyrimidinyl (27) or an ethylpyrrolidinyl (28) substituent, with EC50 in the range of 1.1â6.5 ÎŒM for six human cancer cell lines. Notably, this corresponds to an approximately 30-fold times greater potency than He