title: Antineoplastic agents. 443. Synthesis of the cancer cell growth inhibitor hydroxyphenstatin and its sodium diphosphate prodrug.
abstract: A structure-activity relationship (SAR) study of the South African willow tree (Combretum caffrum) antineoplastic constituent combretastatin A-4 (3b) led to the discovery of a potent cancer cell growth inhibitor designated phenstatin (5a). This benzophenone derivative of combretastatin A-4 showed remarkable antineoplastic activity, and the benzophenone derivative of combretastatin A-1 was therefore synthesized. The benzophenone, designated hydroxyphenstatin (6a), was synthesized by coupling of a protected bromobenzene and a benzaldehyde to give the benzhydrol with subsequent oxidation to the ketone. Hydroxyphenstatin was converted to the sodium phosphate prodrug (6e) by a dibenzyl phosphite phosphorylation and subsequent benzyl cleavage (6a --> 6d --> 6e). While hydroxyphenstatin (6a) was a potent inhibitor of tubulin polymerization with activity comparable to that of combretastatin A-1 (3a), the phosphorylated derivative (6e) was inactive.
authors.affiliation: Cancer Research Institute and Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 872404, Tempe, Arizona 85287-2404, USA.
authors.forename: G R
authors.initials: GR
authors.lastname: Pettit
authors.forename: M P
authors.initials: MP
authors.lastname: Grealish
authors.forename: D L
authors.initials: DL
authors.lastname: Herald
authors.forename: M R
authors.initials: MR
authors.lastname: Boyd
authors.forename: E
authors.initials: E
authors.lastname: Hamel
authors.forename: R K
authors.initials: RK
authors.lastname: Pettit
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001577:Benzophenones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001704:Biopolymers; D003078:Colchicine / Q000737:chemistry; D018360:Crystallography, X-Ray; D011756:Diphosphates / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D014404:Tubulin / Q000737:chemistry; D014407:Tumor Cells, Cultured
chemical_list: D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D001577:Benzophenones; D001704:Biopolymers; D011756:Diphosphates; D014404:Tubulin; C411463:hydroxyphenstatin; C411502:hydroxyphenstatin diphosphate; D003078:Colchicine