Studies on the Alkaloids of Menispermaceous Plants. CCLIX. Alkaloids of Menispermum dauricum DC. (Suppl. 7). Structures of Acutumine and Acutumidine, Chlorine-Containing Alkaloids with a Novel Skeleton

Abstract

Structures of acutumine (XXXVIIa) and acutumidine (XXXVIIb), isolated from Menispermum dauricum DC. and Sinomenium acutum REHD. et WILS. (Menispermaceae), were investigated. On the basis of a series of degradative and spectroscopic evidences, their structures including absolute stereochemistry are assigned to the formula XXXVIIa and XXXVIIb, respectively, which are in good agreement with the result obtained from the X-ray analyses of acutumine and acetylacutumine. Apparently, these alkaloids represent a new class of alkaloids with a novel skeleton and also provide rare examples of chlorine-containing alkaloids.