title: Antitumor agents, 135. Structure and stereochemistry of polacandrin, a new cytotoxic triterpene from Polanisia dodecandra.
abstract: A new dammarane triterpene, polacandrin [1], has been isolated from Polanisia dodecandra. The structure of 1 was established as 1 beta, 3 alpha, 12 beta, 25-tetrahydroxy-20(S),24(S)-epoxydammarane by chemical and spectroscopic methods, which included the concerted application of a number of 2D nmr techniques that involved 1H-1H COSY, HETCOR, NOESY, and long-range HETCOR. Single-crystal X-ray analysis of polacandrin pentahydrate verified the complete structure and stereochemistry. Polacandrin showed potent cytotoxicities against KB (ED50 = 0.60 microgram/ml), P-388 (ED50 = 0.90 microgram/ml), and RPMI-7951 (ED50 = 0.62 microgram/ml) tumor cells.
authors.affiliation: Natural Products Laboratory, School of Pharmacy, University of North Carolina, Chapel Hill 27599.
authors.forename: Q
authors.initials: Q
authors.lastname: Shi
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: Fujioka
authors.forename: Y
authors.initials: Y
authors.lastname: Kashiwada
authors.forename: J J
authors.initials: JJ
authors.lastname: Chang
authors.forename: M
authors.initials: M
authors.lastname: Kozuka
authors.forename: J R
authors.initials: JR
authors.lastname: Estes
authors.forename: A T
authors.initials: AT
authors.lastname: McPhail
authors.forename: D R
authors.initials: DR
authors.lastname: McPhail
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism; D014315:Triterpenes / Q000737:chemistry* / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014961:X-Ray Diffraction
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D014315:Triterpenes