Chemistry of the annonaceae. Structures of uvarindoles A—D, four new benzylated indole alkaloids from Uvaria angolensis

Abstract

Uvaria angolensis stem bark has yielded four alkaloids based on indole substituted with between two and four 6-hydroxybenzyl units; uvarindoles A (1) and B (2) are indentified as indole so substituted at the 1,2,3 and 1,2,3,5 positions respectively, uvarindole C (3) as a 2,3-substituted indole with as the 2 substituent a hydroxybenzoyl unit, and uvarindole D (4) as a dihydroindol-3-one with one hydroxybenzyl unit situated at N(1)and with two units at C(2).