title: 1',2',3',4'-tetradehydrotubulosine, a cytotoxic alkaloid from Pogonopus speciosus.
abstract: Bioassay-guided phytochemical investigation of the stems of Pogonopus speciosus, using human oral epidermoid carcinoma (KB) cells as a monitor, led to the isolation of a novel alkaloid, 1',2', 3',4'-tetradehydrotubulosine (1), along with tubulosine (2) and psychotrine (3) as bioactive constituents. The structure of the novel compound was elucidated through 1D- and 2D-NMR spectroscopic methods. Alkaloids 1 and 3 showed weak cytotoxic activity against a panel of human cancer cell lines, with the potency of these compounds being markedly less than that of tubulosine (2).
authors.affiliation: Program for Collaborative Research in the Pharmaceutical Sciences and Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ito
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
authors.forename: H B
authors.initials: HB
authors.lastname: Chai
authors.forename: M P
authors.initials: MP
authors.lastname: Gupta
authors.forename: N R
authors.initials: NR
authors.lastname: Farnsworth
authors.forename: G A
authors.initials: GA
authors.lastname: Cordell
authors.forename: J M
authors.initials: JM
authors.lastname: Pezzuto
authors.forename: A D
authors.initials: AD
authors.lastname: Kinghorn
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004640:Emetine / Q000031:analogs & derivatives; D006801:Humans; D015394:Molecular Structure; D019666:Rubiaceae / Q000737:chemistry*; D013057:Spectrum Analysis; D014407:Tumor Cells, Cultured
chemical_list: C400161:1',2',3',4'-tetradehydrotubulosine; D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D004640:Emetine