Fractionation of an ethanol extract of a Madagascar collection of the leaves and fruit of Cassipourea lanceolata Tul. led to the isolation of three euphane triterpenoids 1-3. The (1)H and (13)C NMR spectra of all compounds were fully assigned using a combination of 2D NMR experiments, including COSY, TOCSY, HSQC (HMQC), HMBC and ROESY sequences.
View Article and Find Full Text PDFPercentage survival and mean percentage change in height were compared for 19 native tree and shrub species planted at Ankafobe Forest, a degraded fragment of highland forest, at ten months after planting. The species varied considerably in both, survival and growth. Best performers included Macaranga alnifolia (Euphorbiaceae), Harungana madagascariensis (Clusiaceae), Filicium decipiens (Sapindaceae) and Dodonaea madagascariensis (Sapindaceae).
View Article and Find Full Text PDFBioassay-directed separation of the butanol-soluble portion of an extract of Sloanea rhodantha (Baker) Capuron var. Rhodantha (Elaeocarpaceae) active against the drug-sensitive HB3 strain of Plasmodium falciparum led to the isolation of seven phenolic compounds, gallic acid (1), 3,5-di-O-galloylquinic acid (2), 1,6-di-O-galloyl glucopyranoside (3), 3,4,5-tri-O-galloylquinic acid (4), 1-O-eudesmoylquinic acid (5), 1,2,3,6-tetra-O-galloyl glucopyranoside (6), and 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-b-D-glucopyranoside (7). The structure of the new compound 5 was established on the basis of interpretation of its 1D and 2D NMR spectroscopic data.
View Article and Find Full Text PDFBioassay-guided fractionation of the EtOH extracts obtained from a plant identified as Didymochlaena truncatula led to the isolation of two cytotoxic alkaloids, camptothecin and 9-methoxycamptothecin. A second plant collection yielded three lignan derivatives, didymochlaenone A (1), didymochlaenone B (2), and (-)-wikstromol, one stilbene, (E)-3-methoxy-5-hydroxystilbene, and two stigmasterol derivatives, stigmast-4-en-3beta-ol and stigmast-4-en-3-one, but no camptothecins, and it is probable that a coding error led to a mistaken identification of the original extract. The structures of the new compounds 1 and 2 were established on the basis of extensive interpretation of one- and two-dimensional NMR spectroscopic data.
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