KAURANE AND TRACHYLOBANE DITERPENES FROM XYLOPIA-AETHIOPICA

Phytochemical investigation of Xylopia aethiopica (Annonaceae) has res ulted in the isolation of two novel diterpenes, 15-oxo-(-)-trachyloban -19-oic acid and (-)-kaur-15-en-17-al-19-oic acid. Also encountered we re the known compounds 15-hydroxy-(-)-trachyloban-19-oic acid, 15 beta -hydroxy-(-)-kaur-16-en-19-oic acid (as an inseperable mixture), 15-ox o-(-)-kaur-16-en-19-oic acid and sitosterol glucoside. C-13 NMR assign ments of 15-hydroxy-(-)trachyloban-19-oic acid and the assignment of t he configuration of its hydroxyl group at C-15 have been carried out f or the first time.