title: Macroline, akuammiline, sarpagine, and ajmaline alkaloids from Alstonia macrophylla.
abstract: A total of seventeen alkaloids, comprising six macroline (including alstofolinine A, a macroline indole incorporating a butyrolactone ring-E), two ajmaline, one sarpagine, and eight akuammiline alkaloids, were isolated from the stem-bark and leaf extracts of the Malayan Alstonia macrophylla. The structure and relative configurations of these alkaloids were established using NMR, MS and in several instances, confirmed by X-ray diffraction analysis. Six of these alkaloids were effective in reversing multidrug-resistance (MDR) in vincristine-resistant KB cells.
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Siew-Huah
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Yun-Yee
authors.initials: YY
authors.lastname: Low
authors.affiliation: Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Saravana Kumar
authors.initials: SK
authors.lastname: Sinniah
authors.affiliation: Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Kien-Thai
authors.initials: KT
authors.lastname: Yong
authors.affiliation: Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Kae-Shin
authors.initials: KS
authors.lastname: Sim
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: tskam@um.edu.my.
authors.forename: Toh-Seok
authors.initials: TS
authors.lastname: Kam
mesh_terms: D000404:Ajmaline / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D031051:Alstonia / Q000737:chemistry*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; 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; D008958:Models, Molecular; D015394:Molecular Structure; D000078183:Oxindoles; D018515:Plant Leaves / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D026121:Indole Alkaloids; D000078183:Oxindoles; C512190:macroline; D000404:Ajmaline; C475809:sarpagine
keywords: Alstonia macrophylla; Apocynaceae; Indole alkaloids; NMR; Reversal of multidrug-resistance; X-ray crystallography