title: Leuconicines A-G and (-)-eburnamaline, biologically active strychnan and eburnan alkaloids from Leuconotis.
abstract: Seven new indole alkaloids of the Strychnos type, leuconicines A-G (1-7), and a new eburnan alkaloid, (-)-eburnamaline (8), were isolated from the stem-bark extract of two Malayan Leuconotis species. The structures of these alkaloids were established using NMR and MS analysis and in the case of 8 also by partial synthesis. Alkaloids 1-5 reversed multidrug resistance in vincristine-resistant KB cells.
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, Iwaki Meisei University, 5-5-1 Iino, Chuo-dai, Iwaki, Fukushima 970-8551, Japan.
authors.forename: Chew-Yan
authors.initials: CY
authors.lastname: Gan
authors.forename: Yun-Yee
authors.initials: YY
authors.lastname: Low
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Etoh
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hayashi
authors.forename: Kanki
authors.initials: K
authors.lastname: Komiyama
authors.forename: Toh-Seok
authors.initials: TS
authors.lastname: Kam
mesh_terms: D018432:Drug Resistance, Multiple; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007624:KB Cells; D008296:Malaysia; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013237:Stereoisomerism; D014750:Vincristine / Q000494:pharmacology
chemical_list: D026121:Indole Alkaloids; C546252:eburnamaline; D014750:Vincristine