title: Synthesis and cytotoxicity of desmethoxycallipeltin B: lack of a quinone methide for the cytotoxicity of callipeltin B.
abstract: The desmethoxy analogue of the cytotoxic, cyclic depsipeptide callipeltin B was synthesized to evaluate the role of its beta-MeOTyr residue. The IC(50) of desmethoxycallipeltin B, in which the beta-MeOTyr residue was replaced by d-Tyr, against HeLa cells was found to be 128+/-10 microM in an MTT assay, compared to 98+/-5 microM 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.
authors.affiliation: Department of Chemistry and Cancer Center, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, USA.
authors.forename: Ravi
authors.initials: R
authors.lastname: Krishnamoorthy
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Richardson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lipton
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D045563:Indolequinones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000970:Antineoplastic Agents; D045563:Indolequinones; D010456:Peptides, Cyclic; C516600:callipeltin B; C525154:desmethoxycallipeltin B; C068040:quinone methide