On the botanical distribution of chiral forms of gossypol.

Plants belonging to Malvaceae (about 90 species belonging to 33 genera) were analysed for the presence of gossypol by reversed-phase HPLC using absorbance detection at 365 nm, and the chirality and optical purity of gossypol were determined whenever the analysis was positive. Only plants belonging to the cotton tribe (Gossypieae) contained gossypol (detection limit better than 0.001%). In particular, no gossypol could be detected in ABELMOSCHUS ESCULENTUS (ocra), HIBISCUS TILIACEUS, H. SABDARIFFA, and HEREA BRASI-LIENSIS, earlier claimed to contain this compound. Gossypol-containing plants usually produced dextrorotatory gossypol of varying optical purity; an enantiomeric excess of (-)-gossypol was detected in only one plant, GOSSYPIUTN BARBADENSE.