title: Cytotoxic vobasine, tacaman, and corynanthe-tryptamine bisindole alkaloids from Tabernaemontana and structure revision of tronoharine.
abstract: Seven new indole alkaloids (1-7) comprising four vobasine, two tacaman, and one corynanthe-tryptamine bisindole alkaloid were isolated from the stem-bark extract of a Malayan Tabernaemontana. Two of the new vobasine alkaloids (1, 3), as well as 16-epivobasine (15) and 16-epivobasenal (17), showed appreciable cytotoxicity toward KB cells (IC50 ca. 5 μg/mL). The structure of the known Tabernaemontana alkaloid tronoharine (8) was revised based on newly acquired NMR data, as well as X-ray diffraction analysis.
authors.affiliation: Department of Chemistry and ‡Institute of Biological Sciences, University of Malaya , 50603 Kuala Lumpur, Malaysia.
authors.forename: Dawn Su-Yin
authors.initials: DS
authors.lastname: Sim
authors.forename: Kam-Weng
authors.initials: KW
authors.lastname: Chong
authors.forename: Choy-Eng
authors.initials: CE
authors.lastname: Nge
authors.forename: Yun-Yee
authors.initials: YY
authors.lastname: Low
authors.forename: Kae-Shin
authors.initials: KS
authors.lastname: Sim
authors.forename: Toh-Seok
authors.initials: TS
authors.lastname: Kam
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D007211:Indoles / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008296:Malaysia; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D032068:Pausinystalia; D010946:Plants, Medicinal / Q000737:chemistry*; D030014:Tabernaemontana / Q000737:chemistry*; D014363:Tryptamines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D026121:Indole Alkaloids; D007211:Indoles; D014363:Tryptamines; C520379:tacaman; C057239:vobasine; C030820:tryptamine