Isolation and chemical analysis of a fatty acid fraction of Kalanchoe pinnata with a potent lymphocyte suppressive activity

Previously we demonstrated that Kalonchoe pinnata (KP) leaf extracts inhibi ted in vitro lymphocyte proliferation and showed in vivo immunosuppressive activity. Here we attempt to identify the immunosuppressive substances pres ent in KP guided by the lymphoproliferative assays. From the ethanolic extr act was purified a fraction (KP12SA) twenty-fold more potent to black murin e lymphocyte proliferation than the crude extract. Chemical analysis by H-1 - and C-13-NMR, IR and GC-MS of KP12SA (methylated sample) showed 89.3% of palmitic acid (C-16). 10.7% of stearic acid (C-18) and traces of arachidic (C-20) and behenic acids (C-22). This study provides evidence that fatty ac ids present in Kalanchoe pinnota may be responsible, at least in part, for its immunosuppressive effect in vivo.