THE STRUCTURE OF BIKHACONITINE

Abstract

Aconitum spicatum Stapf has been found to contain two major alkaloids, pseudaconitine and bikhaconitine. The latter (C36H51O11N) contains one free hydroxyl, four aliphatic methoxyl groups, one acetic and one veratric ester group, while the former (C36H51O12N) contains the same substituents plus a second free hydroxyl. Like pseudaconitine, which forms a pyroderivative hydrolyzable to pyropseudaconine, which can be isomerized to isopyropseudaconine, bikhaconitine gives rise to pyrobikhaconitine, pyrobikhaconine, and isopyrobikhaconine. Bikhaconitine was assumed to differ from pseudaconitine in lacking one secondary hydroxyl. The correctness of this assumption was proved by the conversion of pseudaconitine into bikhaconitine and further to triacetylbikhaconine. This correlation establishes the structure of bikhaconitine and also, since pseudaconitine had previously been correlated with aconitine, establishes its absolute configuration.