Abstract: | From the leaves of the Apocynaceae Pleiocarpa talbotii WERNHAM three new indole alkaloids were isolated and identified as 3,4,5,6-tetradehydrotalbotine ( 2 ), 5,6-dehydrotalbotine ( 3 ) and deformyl talbotinic acid methylester ( 4 ). From the stem bark of the same plant normacusine B (tombozine) was isolated. |