title: Oxidized derivatives of macroline, sarpagine, and pleiocarpamine alkaloids from Alstonia angustifolia.
abstract: A total of 20 new indole alkaloids comprising mainly oxidized derivatives of macroline- (including alstofonidine, a macroline indole incorporating a butyrolactone ring-F), pleiocarpamine-, and sarpagine-type alkaloids were isolated from the bark and leaf extracts of Alstonia angustifolia. The structures and relative configurations of these alkaloids were determined using NMR and MS analyses and in some instances confirmed by X-ray diffraction analyses. Alkaloids 3, 7, 35, and 41 showed moderate to weak activity, while 21 showed strong activity in reversing multidrug resistance in vincristine-resistant KB cells.
authors.affiliation: Department of Chemistry and ‡Institute of Biological Sciences, University of Malaya , 50603 Kuala Lumpur, Malaysia.
authors.forename: Shin-Jowl
authors.initials: SJ
authors.lastname: Tan
authors.forename: Jun-Lee
authors.initials: JL
authors.lastname: Lim
authors.forename: Yun-Yee
authors.initials: YY
authors.lastname: Low
authors.forename: Kae-Shin
authors.initials: KS
authors.lastname: Sim
authors.forename: Siew-Huah
authors.initials: SH
authors.lastname: Lim
authors.forename: Toh-Seok
authors.initials: TS
authors.lastname: Kam
mesh_terms: D000470:Alkaloids; D031051:Alstonia / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006801:Humans; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D000078183:Oxindoles; D018515:Plant Leaves / Q000737:chemistry; D014750:Vincristine / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D026121:Indole Alkaloids; D000078183:Oxindoles; C512190:macroline; C114765:pleiocarpamine; D014750:Vincristine; C475809:sarpagine