RÉSUMÉ
Objective: To study the chemical constituents of Myrrha and their antitumor activities. Methods: The constituents were isolated and purified by recrystallization, and open silica gel, Sephadex LH-20, ODS column chromatography, as well as preparative HPLC. The structures were elucidated based on the chemical and spectroscopic methods. Furthermore, the cytotoxicities of these chemical components against PC-3 cell lines were measured by MTT method. Results: Eleven compounds were obtained from the chloroform extract of myrrh, and were established as (4α,11α)-2-oxo-8,11-dihydroxycadina-1(6),7,9-trien-12-oic acid γ-lactone (1), (4α,11β)-2-oxo-8,11-dihydroxycadina-1(6),7,9-trien-12-oic acid γ-lactone (2), dihydropyrocurzerenone (3), orientalol E (4), guaianediol (5), cryptomeridiol (6), cycloartane-1α,2α,3β,25-tetrol (7), cycloartan-24-ene-1α,2α,3β-triol (8), cycloartan-24-ene-1α,3β-diol (9), 29-norlanost-8,24-dien-1α,2α,3β-triol (10), and octadecane-1,2S,3S,4R-tetrol-1-O-α-L-rhamnopyranoside (11). Conclusion: Compounds 1 and 2 are two new compounds named as (+)-myrrhalactone A and (-)-myrrhalactone A, respectively. Compounds 4 and 6 are isolated from the genus Commiphora Engl. for the first time. Compounds 8, 10, and 11 show moderate cyctotoxic activity against PC-3 cell lines.