title: Quassinoids from Eurycoma longifolia.
abstract: Ten new structurally diverse quassinoids (1-10) and 14 known compounds were isolated from the stems of Eurycoma longifolia. The new compounds were two eurycomanone-type C(20) quassinoids (1, 2), one klaineanone-type C(20) quassinoid (3), one C(19) quassinoid (4) with a 1,2-seco-1-nor-6(5-->10)-abeo-picrasan-2,5-olide skeleton, and six eurycomalactone-type C(19) quassinoids (5-10). Compounds 5 and 6 both possessed a 3,4-epoxy group observed for the first time in eurycomalactones. Compound 1 had an alpha-oriented OH group at C-14 that had not been reported previously in eurycomanone-type quassinoids. All of the isolates were evaluated for cytotoxicity toward the highly metastatic HT-1080 human fibrosarcoma cell line, and compounds 11, 23, and 24 showed potent cytotoxicity (IC(50) values 0.93-1.1 microM).
authors.affiliation: Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Miyake
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tezuka
authors.forename: Suresh
authors.initials: S
authors.lastname: Awale
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Kadota
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D035701:Eurycoma / Q000737:chemistry*; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D018547:Plant Stems / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D036702:Quassins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D036702:Quassins