An efficient synthetic strategy for three natural seco-type cholestane alkaloids isolated from the Veratrum plants, based on commercially available naturally occurring and abundant (−)-diosgenin (1), as exemplified in the concise asymmetric synthesis of (−)-verazine (4), (−)-veramiline (5) (proposed structure), and its 22-epimer, (−)-oblonginine (6), is presented. This work highlights the application
DNA-Damaging Steroidal Alkaloids from <i>Eclipta</i> <i>alba</i> from the Suriname Rainforest
作者:Maged S. Abdel-Kader、Brian D. Bahler、Stan Malone、Marga C. M. Werkhoven、Frits van Troon、David、Jan H. Wisse、Isia Bursuker、Kim M. Neddermann、Stephen W. Mamber、David G. I. Kingston
DOI:10.1021/np970561c
日期:1998.10.1
Bioassay-guided fractionation of the MeOH extract of Ecliptaalba using three yeast strains (1138, 1140, and 1353) resulted in the isolation of eight bioactive steroidalalkaloids (1-8), six of which are reported for the first time from nature. The major alkaloid was identified as (20S)(25S)-22,26-imino-cholesta-5,22(N)-dien-3beta-ol (verazine, 3), while the new alkaloids were identified as 20-epi-3-dehydroxy-3-oxo-5