A new stereoisomer of stemmadenine alkaloid from Tabernaemontana heyneana

A new alkaloid, 15-beta-stemmadenine, was isolated from the fruits of Tabernaemontana heyneana Wall. from the ethanolic extract. The complete H-1 and C-13 NMR assignments of the compound were carried out using COSY, HMQC and HMBC. Stereochemistry at C-15 and C-16 was established using ROESY and temperature-dependent H-1 NMR studies. Copyright (C) 2002 John Wiley Sons, Ltd.