kopsia singapurensis/neoplasms

Five new aspidofractinine-type alkaloids, kopsiahainins A-E (1-5), were isolated from a 80% EtOH extract of the leaves and stems of Kopsia hainanensis. Structural elucidation of all the compounds were performed by spectral methods such as 1D- and 2D-NMR, IR, UV, and HR-ESI-MS. Alkaloids 3 and 4

A phytochemical investigation on the 90% ethanol aqueous extract of the aerial part of Kopsia arborea led to the isolation of three new monoterpenoid indole alkaloids, kopsiarborines A-C (1-3). The new structures were elucidated by using spectroscopic data (NMR, IR, UV, and MS). The

A chemical investigation on the 80% EtOH extract of the aerial parts of Kopsia fruticosa led to five new indole alkaloids, kopsifolines G-K (1-5), and one known alkaloid, kopsifoline A (6). Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (1H-1H COSY,

Three new alkaloids were isolated from the bark extract of the Malayan Kopsia arborea, viz., arbophyllidine (1), an unusual pentacyclic, monoterpenoid indole characterized by an absence of oxygen atoms and incorporating a new carbon-nitrogen skeleton, and arbophyllinines A (2)

The ethanol extract of the twigs and leaves of Kopsia hainanensis afforded six new aspidofractinine alkaloids, kopsiahainanins A-F (1-6), among which alkaloids 1 and 2 possessed a lactone bridge with novel regiochemistry. The structures of the isolated compounds were established based on 1D and 2D

Kopsiflorine, an indole alkaloid of the aspidofractinine-type isolated from Kopsia dasyrachis, was examined for its effect in enhancing drug cytotoxicity in multidrug-resistant tumor cells. The cytotoxicity of vincristine was enhanced in a concentration-dependent manner by kopsiflorine in

Three new monoterpenoid indole alkaloids, kopsiaofficines A-D (1-3), were isolated from the 95% EtOH extract of the aerial parts of Kopsia officinalis. Their structures were established on the basis of spectroscopic data. The isolated alkaloids were tested in vitro for cytotoxic

A chemical investigation on the 70% ethanol extract from the leaves and stems of Kopsia lancibracteolata Merr. resulted in the isolation of three new methyl chanofruticosinate type alkaloids, 12-hydroxyl prunifoline A (1), 12-hydroxyl prunifoline C (2), and N(4)-oxide prunifoline D (3). Structural

BACKGROUND Studies have shown that the barks and roots of some Apocynaceae species have anticancer and antimalarial properties. In this study, leaf extracts of five selected species of Apocynaceae used in traditional medicine (Alstonia angustiloba, Calotropis gigantea, Dyera costulata, Kopsia

BACKGROUND The anticancer properties of Apocynaceae species are well known in barks and roots but less so in leaves. METHODS In this study, leaf extracts of 10 Apocynaceae species were assessed for antiproliferative (APF) activities using the sulforhodamine B assay. Their extracts were also analyzed