RESUMEN
Objective To investigate the chemical constituents in Desmodium blandum and their antitumor bioactivity.Methods Various chromatographic techniques were employed for the isolation and purification of the constituents by butanol at 50 ℃ including silica gel, Sephadex LH-20.The compounds structures were elucidated by spectral analyses(IR,UV,NMR,and MS).Then their cytotoxic activity was studied.Results They were identified as N,N-dimethyltryptamine (Ⅰ),5-methoxy-N,N-dimethyltryptamine(Ⅱ),citrusinol(Ⅲ),yukovanol(Ⅳ),(Z)-1-(4-hydroxy-2,3-dimethoxyphenyl)-3-(4-hydroxyphenyl) propene(Ⅴ),(Z)-1-(3-hydroxy-2,4-dimethoxy phenyl)-3-(4-hydroxy-3-methoxy-phenyl) propene(Ⅵ),methyl protocatechuate(Ⅶ),katuranin(Ⅷ).Conclusion Eight compounds are isolated from the stems of D.blandum for the first time.In the MTT antitumor experiments,compounds Ⅰ and Ⅲ—Ⅵ have the cytotoxic activity to KB cell.