Constituents of regenerated plants of Ophiorrhiza pumila; formation of a new glycocamptothecin and predominant formation of (3R)-deoxypumiloside over (3S)-congener
Abstract The regeneration of plantlets was successful from Ophiorrhiza pumila callus cultures, from which a new glucosyloxy camptothecin, 9-β-glucosyloxycamptothecin, together with 15 metabolites including six camptothecin-related alkaloids was isolated. (3S)-Deoxypumiloside, one of the plausible biogenetic precursors of camptothecin, could not be found, whereas the (3R) epimer was isolated from the regenerated plants.