Anticomplement Activity of Compounds Isolated from the Roots of Euphorbia kansui

The anticomplement activity-guided fractionation of the methanol extract of Euphorbia kansui L. resulted in isolation of three diterpenes, two triterpenes, and two sterols (1-7) from ethyl acetate fraction. By spectroscopic analysis, their chemical structures were elucidated as: β-amyrin (1); kansuiphorin C (2); 3-O-(2'E,4'Z-decadienoyl)-ingenol (3); 3-O-(2,3-dimethylbutyryl)-13-O-n-dodecanoyl-13-hydroxyingenol (4); β-sitosterol (5); α-euphol (6); β-sitosterol-3-O-β-D-glucopyranoside (7). These compounds were investigated in vitro for their anticomplement activily against the classical pathway of the complement system, with compounds 2-4 exhibiting significant anticomplement activity with respective 50% inhibitory concentration values of 44.1±3.8, 89.5±5.5, and 152.1±6.2 μM.