Synthesis and cytotoxicity of desmethoxycallipeltin B: Lack of a quinone methide for the cytotoxicity of callipeltin B
摘要:
The desmethoxy analogue of the cytotoxic, cyclic depsipeptide callipeltin B was synthesized to evaluate the role of its beta-MeOTyr residue. The IC50 of desmethoxycallipeltin B, in which the beta-MeOTyr residue was replaced by D-Tyr, against HeLa cells was found to be 128 +/- 10 mu M in an MTT assay, compared to 98 5 mu M for the natural product itself. The roughly comparable cytotoxicities suggest that the cytotoxicity of callipeltin B does not arise through the formation of a quinone methide intermediate. (c) 2007 Elsevier Ltd. All rights reserved.