Cephalezomines G, H, J, K, L, and M, new alkaloids from Cephalotaxus harringtonia var. nana

Five new cephalotaxine-type alkaloids, cephalezomines G, H, J, K, and L (1-5), and a new homoerythrina-type alkaloid, cephalezomine M (6), have been isolated from the leaves of Cephalotaxus harringtonia var. nana. The relative and absolute stereochemistry was elucidated by NOESY data, CD analysis applying exciton chirality methods, and chemical means. (C) 2002 Elsevier Science Ltd. All rights reserved.