title: C6-C8 bridged epothilones: consequences of installing a conformational lock at the edge of the macrocycle.
abstract: A series of conformationally restrained epothilone analogues with a short bridge between the methyl groups at C6 and C8 was designed to mimic the binding pose assigned to our recently reported EpoA-microtubule binding model. A versatile synthetic route to these bridged epothilone analogues has been successfully devised and implemented. Biological evaluation of the compounds against A2780 human ovarian cancer and PC3 prostate cancer cell lines suggested that the introduction of a bridge between C6-C8 reduced potency by 25-1000 fold in comparison with natural epothilone D. Tubulin assembly measurements indicate these bridged epothilone analogues to be mildly active, but without significant microtubule stabilization capacity. Molecular mechanics and DFT energy evaluations suggest the mild activity of the bridged epo-analogues may be due to internal conformational strain.
authors: Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322, USA. weiqiang.zhan@emory.edu
authors: Weiqiang
authors: W
authors: Zhan
authors: Yi
authors: Y
authors: Jiang
authors: Shubhada
authors: S
authors: Sharma
authors: Peggy J
authors: PJ
authors: Brodie
authors: Susan
authors: S
authors: Bane
authors: David G I
authors: DG
authors: Kingston
authors: Dennis C
authors: DC
authors: Liotta
authors: James P
authors: JP
authors: Snyder
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015195:Drug Design; D004354:Drug Screening Assays, Antitumor; D034261:Epothilones / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008958:Models, Molecular; D010051:Ovarian Neoplasms / Q000188:drug therapy*; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D034261:Epothilones