RESUMO
Aim To explore the anticomplementary ac-tivity and active constituents of Phyllanthus urinaria. Methods Being guided by bioactive screening,the anticomplementary constituents of P.urinaria were iso-lated and purified by solution partition and chromato-graphic techniques,and their structures were identified by 13C-NMR spectrum and the comparison of reported data. The anticomplementary activity and possible mechanism were assayed.Results The EtOAc fraction of the methanol extract of P.urinaria was shown to be the active fraction,and two compounds were purified from the fraction and were identified as corilagin and ellagic acid.The EtOAc and the two compounds signifi-cantly inhibited the hemolysis of the complement classi-cal pathway,with IC50values of 53.77 mg·L-1, 176.54 mg·L-1and 102.23 mg·L-1,respectively. While they just showed slight effect on inhibiting the hemolysis of the complement alternative pathway. All of them affected the formation of C3 convertase of the classical pathway. Conclusions The polyphenols are main anticomplentary constituents of P. urinaria,and its mechanism is related to inhibiting formation of C3 convertase of the classical pathway.