Circular dichroism studies of bisindole Vinca alkaloids

[摘要] The analysis of a series of seventeen vinblastine analogs by circular dichroism is described. Exciton coupling of the indole and indoline chromophores of these compounds provides a general, nonempirical method for the assignment of the C16' configuration with the bioactive C16'-S and the inactive C16'-R analogs giving rise, respectively, to positive and negative couplets. An analysis of the noncoupled transitions of the CDs indicates that a positive Cotton effect at 305 nm, although empirical, is associated with bioactivity. Theoretical calculations of the UV and CD spectra of vinblastine diastereomers are also described. (C) 1998 Elsevier Science Ltd. All rights reserved.

[发布日期] 1998-12-24

[关键词] circular dichroism;electronic spectra;alkaloids;theoretical studies