The alkaloids of Schefferomitra subaequalis (Anonaceae)

Abstract

Eight alkaloids were isolated from the bark of Scheferomitra subaequalis (Scheff.) Diels. In addition to the previously reported anonaine and liriodenine, three known alkaloids, asimilobine, isoboldine, and anolobine, and three new ones, aequaline, schefferine, and alkaloid Y were isolated from the bark. The leaves yielded the six colourless alkaloids present in the bark, while the two yellow ones, liriodenine and alkaloid Y, were absent. The structure and absolute configuration of aequaline was elucidated as (S)-3,9-dihydroxy-2,l0-dimethoxytetrahydoproto-berberine and that of schefferine as (8)-9-hydroxy-2,3,10-trimethoxytetrahydro-protoberberine.