Cytotoxic flavonol glycosides from Triplaris cumingiana.

Three new compounds, 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-oxo-4H-chromen-3-yl-4,6-bis-O-beta-D-(3,4,5-trihydroxybenzoyl)glucopyranoside (1), 5,7-dihydroxy-2-(4-hydroxyphenyl)-4-oxo-4H-chromen-3-yl-5-O-alpha-L-(3,4,5-trihydroxybenzoyl)arabinofuranoside (2), and 2-hydroxy-4-O-alpha-L-(3,5,7-trihydroxy-4-oxo-4H-chromen-2-yl)phenylarabinofuranoside (3), were isolated from the young leaves of Triplaris cumingiana, together with two known compounds, quercetin 3-O-alpha-L-(5"-O-galloyl)arabinofuranoside (4) and quercetin 3-O-beta-D-(6"-O-galloyl)glucopyranoside (5). The structures of 1-3 were established by spectroscopic methods. Compounds 1-5 were evaluated for their cytotoxic activities against the MCF-7, H-460, and SF-268 human cancer cell lines.

New cytotoxic naphthopyrane derivatives from Adenaria floribunda.

Bioassay-guided fractionation of an EtOAc/MeOH extract of Adenaria floribunda young leaves using MCF-7, H-460, and SF-268 cancer cell lines yielded four new active compounds named adenaflorins A-D (1-4). Their chemical structures were determined by spectroscopic means. Adenaflorin A (1) was the most cytotoxic.