Quassinoids from the Root of Eurycoma longifolia and Their Antiproliferative Activity on Human Cancer Cell Lines

BACKGROUND: The roots of Eurycoma longifolia Jack have traditionally been used as an aphrodisiac tonic besides the other remedies for boils, fever, bleeding gums, and wound ulcer. Recently, the antiproliferative activity of E. longifolia has been reported and remained attractive to natural chemists. OBJECTIVE: The objective of this study was to study on antiproliferative compounds from the root of E. longifolia. MATERIALS AND METHODS: Column chromatography was used to separate individual compounds, spectroscopic data including nuclear magnetic resonances and mass spectrometry were analyzed to determine the chemical structure of the isolates and for biological testing, antiproliferative activity of compounds was tested on seven human cancer cell lines (KATO III, HCT-15, Colo205, HepG2, PC-3, Jurkat, HL-60) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. RESULTS: Nine quassinoids including a new C(19) longilactone-type quassinoid glycoside were characterized from the roots of the title plant. Among them, the major quassinoid eurycomanone exhibited selectively potential antiproliferative activities on the leukemia cell lines (HL-60 and Jurkat) and had very low toxic effects on normal skin fibroblast cell line (NB1RGB). CONCLUSION: The current study reveals one new quassinoid glycoside and the potential active component (eurycomanone) from E. longifolia for the leukemia treatment. SUMMARY: Nine quassinoids (1-9) including one new quassinoid glycoside (9) and eight known ones were isolated from the roots of Eurycoma longifolia. The structure of the new quassinoid 9 was determined by extensive chemical and spectroscopic analyses. The major quassinoid, eurycomanone (3), exhibited selectively potential antiproliferative activities on both Jurkat and HL-60 leukemia cells and had very low toxic effects on normal skin fibroblast cell line (NB1RGB). Abbreviations used: COSY: Correlation spectroscopy; HMBC: Heteronuclear multiple-bond correlation; HMQC: Heteronuclear multiple quantum correlation; NMR: Nuclear magnetic resonance; NOESY: Nuclear Overhauser enhancement spectroscopy; TLC: Thin layer chromatography.