Novel ceramide 1-sulfates, potent DNA topoisomerase I inhibitors isolated from the Bryozoa Watersipora cucullata
作者:Makoto Ojika、Go Yoshino、Youji Sakagami
DOI:10.1016/s0040-4039(97)00852-6
日期:1997.6
Two ceramide 1-sulfates 1 and 2 have been isolated from the Japanese Bryozoa Watersipora cucullata as new potent inhibitors of a human DNA topoisomerase I. The gross structures of 1 and 2 were determined by spectroscopic analysis, and their absolute stereochemistry was elucidated by the optical data of degradation products.
Sphinga-4,8-dienine derivatives were synthesized from a vinyl-epoxide 5 via three routes. First, reaction of 5 with 2-dodecenyl cyanocuprate afforded a 1:1 mixture of (4E,8E)- and (4E,8Z)-sphingadienine derivatives in high yield. Second, the (4E,8E)-isomer was selectively synthesized via allylic bromide-allylic sulfone coupling followed by desulfonylation. Third, the (4E,8Z)-isomer was selectively