Biologically active ibogan and vallesamine derivatives from Tabernaemontana divaricata.
Six new indole alkaloids, viz., (3S)-3-cyanocoronaridine (2), (3S)-3-cyanoisovoacangine (3), conolobine A (5), conolobine B (6), conolidine (7), and (3R/3S)-3-ethoxyvoacangine (8), in addition to 36 known ones, were obtained from the stem-bark extract of the Malayan Tabernaemontana divaricata. The structures were determined by NMR and MS analysis. The CN-substituted alkaloids showed appreciable cytotoxicity towards the KB human oral epidermoid carcinoma cell-line.
Kam
Toh-Seok
TS
Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia. tskam@um.edu.my
Pang
Huey-Shen
HS
Choo
Yeun-Mun
YM
Komiyama
Kanki
K
D045744:Cell Line, Tumor; D006801:Humans; D007050:Ibogaine / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D018547:Plant Stems; D030014:Tabernaemontana
D026121:Indole Alkaloids; D010936:Plant Extracts; D007050:Ibogaine