[Studies on chemical constituents of two plants from Costus].

OBJECTIVE To study the chemical constituents of Costus speciosus and C. tonkinensis (Zingiberaceae) distributed in Yunnan province. METHOD Chromatography and spectral analyses were used to isolate the constituents and elucidate their structure. RESULT Six compounds were isolated from the rhizome of C. speciosus and elucidated as diosgenin(1), prosapogenin B of dioscin(2), diosgenone(3), cycloartanol(4), 25-en-cycloartenol(5) and octacosanoic acid(6). Four compounds were isolated from the rhizome of Costus tonkinensis and elucidated as tetracosanoic acid(7), succinic acid(8), beta-sitosterol(9) and daucosterin(10). CONCLUSION Compounds of 3-6 were obtained from C. speciosus for the first time and compounds of 7-10 were obtained from C. tonkinensis for the first time too.