9-methoxycanthin-6-one and canthin-6-one

The roots of Eurycoma longifolia have been used in many countries of Southeast Asia to alleviate various diseases including malaria, dysentery, sexual insufficiency, and rheumatism. Although numerous studies have reported the pharmacological properties of E. longifolia, the mode of action of the anti-inflammatory activity has not been elucidated. Bioguided isolation of NF-κB inhibitors using an NF-κB-driven luciferase reporter gene assay led to the identification of a new quassinoid, eurycomalide C (1), together with 27 known compounds including 11 quassinoids (2-12), six alkaloids (13-18), two coumarins (19, 20), a squalene derivative (21), a triterpenoid (22), and six phenolic compounds (23-28) from the extract of E. longifolia. Evaluation of the biological activity revealed that C19-type and C20-type quassinoids, β-carboline, and canthin-6-one alkaloids are potent NF-κB inhibitors, with IC50 values in the low micromolar range, while C18-type quassinoids, phenolic compounds, coumarins, the squalene derivative, and the triterpenoid turned out to be inactive when tested at a concentration of 30 μM. Eurycomalactone (2), 14,15β-dihydroklaieanone (7), and 13,21-dehydroeurycomanone (10) were identified as potent NF-κB inhibitors with IC50 values of less than 1 μM.

Topics: Alkaloids; Carbolines; Coumarins; Drug Screening Assays, Antitumor; Eurycoma; Furans; HeLa Cells; Humans; Indole Alkaloids; Inhibitory Concentration 50; Molecular Structure; NF-kappa B; Plant Roots; Plants, Medicinal; Quassins; Squalene; Vietnam

Eight compounds were isolated from the stems of Brucea mollis by various chromatographic techniques such as column chromatography on silica gel and Sephadex LH-20, and preparative HPLC, and their structures were elucidated as bruceolline O (1), 1-(1-beta-glucopyranosyl)-1H-indole-3-carbaldehyde (2), canthin-6-one (3), 11-hydroxycanthin-6-one (4), 9-methoxycanthin-6-one (5), 4-methoxycanthin-6-one (6), infractin (7), and beta-carboline-1-propionic acid (8). The cytotoxic activities of compounds 1-8 against HCT-8 and A549 human cell lines were determined, but none of them exhibited significant activity (IC 50 > 10 micromol x L(-1)). Among them, compound 1 is a new indole alkaloid, and compounds 2 and 5-7 were isolated from this plant for the first time.

Topics: Antineoplastic Agents, Phytogenic; Brucea; Carbolines; Cell Line, Tumor; Humans; Indole Alkaloids; Molecular Structure; Plant Stems; Plants, Medicinal