Biflavonoids and a glucopyranoside derivative from Ouratea semiserrata.

Abstract

Two new biflavonoids, 5-hydroxy-7-methoxyflavone-(4 →O→8 )-4 ,5 ,7 -trihydroxyflavone and 5-hydroxy- 7-methoxyflavone-(4 →O→8 )-5 ,7 -dihydroxy-4 -methoxyflavone, and the glucopyranoside derivative, 1-O-(4-hydroxyphenyl)-6-O-(4-hydroxybenzoyl)- -D-glucopyranoside, as well as the known biflavones lanaraflavone, amentoflavone and podocarpusflavone, the triterpenes lupeol and friedelin, the lignans eudesmin and epieudesmin, the flavonol glycoside rutin, the steroids -sitosterol, stigmasterol, 3 - O- -D-glucopyranosylsitosterol, 7-oxostigmast-5-en-3 -ol and 7-oxostigmasta-5,22-dien-3 -ol, the carbohydrates - and -glucopyranose and 1-O-(4-hydroxybenzoyl)- -D-glucopyranoside, and the norsesquiterpene 6,9-dihydroxymegastigma-4,7-dien-3-one, have been isolated from leaves and branches of Ouratea semiserrata. The structures of these compounds were established from spectral data, including twodimensional NMR experiments and mass spectra.