Phytochemical investigation of Turnera diffusa.

A phytochemical investigation of Turnera diffusa afforded 35 compounds, comprised of flavonoids, terpenoids, saccharides, phenolics, and cyanogenic derivatives, including five new compounds (1-5) and a new natural product (6). These compounds were characterized as luteolin 8-C-E-propenoic acid (1), luteolin 8-C-beta-[6-deoxy-2-O-(alpha-l-rhamnopyranosyl)-xylo-hexopyranos-3-uloside] (2), apigenin 7-O-(6' '-O-p-Z-coumaroyl-beta-d-glucopyranoside) (3), apigenin 7-O-(4' '-O-p-Z-coumaroylglucoside) (4), syringetin 3-O-[beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside] (5), and laricitin 3-O-[beta-d-glucopyranosyl-(1-->6)-beta-d-glucopyranoside] (6). Their structures were determined by spectroscopic and chemical methods.