title: Biologically active aspidofractinine alkaloids from Kopsia singapurensis.
abstract: Ten new indole alkaloids of the aspidofractinine type, in addition to several recently reported indole alkaloids and 20 other known alkaloids, were obtained from the leaf and stem-bark extract of the Malayan Kopsia singapurensis, viz., kopsimalines A-E (1-5), kopsinicine (6), kopsofinone (7), and kopsiloscines H-J (8-10). The structures of these alkaloids were determined using NMR and MS analysis. Kopsimalines A (1), B (2), C (3), D (4), and E (5) and kopsiloscine J (10) were found to reverse multidrug-resistance in vincristine-resistant KB cells, with 1 showing the highest potency.
authors: Department of Chemistry, University of Malaya, Kuala Lumpur, Malaysia.
authors: G
authors: G
authors: Subramaniam
authors: Osamu
authors: O
authors: Hiraku
authors: Masahiko
authors: M
authors: Hayashi
authors: Takashi
authors: T
authors: Koyano
authors: Kanki
authors: K
authors: Komiyama
authors: Toh-Seok
authors: TS
authors: Kam
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029062:Apocynaceae / Q000737:chemistry*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; 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; D024301:Plant Bark / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D014750:Vincristine / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D026121:Indole Alkaloids; D014750:Vincristine