PECRASSIPIhIES A AI\D B, SEC O. BISBEN ZYLIS O QUINOLINE ALKALOIDS FROM PHAEANTHA S CRASSIPETALU S

Chemical investigation on the bark of Phaeanthus crassipetalus (Annonaceae) yielded two new seco-bisbenzylisoquinoline alkaloids, (+)-pecrassipine A (1) and (-)-pecrassipine B (2), together with seven known alkaloids. Their structures were elucidated by two-dimensional NMR techniques. Pecrassipines A and B exhibited a vasorelaxant activity on isolated rat aorta ring.