The separation procedure was guided by a bioassay using MD-A-MB-23 cells,and the column chromatography over silica gel,Sephadex LH-20 was employed for the purification of compounds from 95% ethyl alcohol extract of B. Rynehopetera.Their structures were fully determined based on spectroscopic analysis including HR-EMI-MS,¹H NMR and ¹³C NMR.The compound cytotoxicity was evaluated in vitro against MD-A-MB-23 cells by MTT method.After anti-tumor-guide purification,six active compounds with antitumor activity were isolated from ethyl acetate fraction of 95% ethyl alcohol extract of B. Rynehopetera.These compounds were identified as hydroquinone(1),2-methyl-1,4-benzenediol(2),2-ethyl-1,4-benzenediol(3),hydroxytyrosol(4),1-(3,4-dihydroxyphenyl) isochroman-6,7-diol(5)and 2,5-dihydroxyphenethyl 2-hydroxypropanoate(6).The six active compounds are all phenolic derivatives.It is for the first time that compound 4 was isolated from the B. Rynehopetera and compounds 4,5 and 6 showed the moderate cytotoxic activity against MD-A-MB-23 cells.Compounds 1,2 and 3 showed strong activities.The hydrogen at the di-position of the benzene ring of compound 1 was replaced respectively by methyl (2) or ethyl (3),and their IC₅₀ of MD-A-MB-23 cells decreased from 69.86 μg/mL to 6.76 and 2.64 μg/mL.