Lanostane triterpenes isolated from epidermis of Poria cocos

Four new lanostane triterpenes together with twenty-two known lanostane triterpenes were isolated from the epidermis of Poria cocos . The chemical structures of all compounds were determined mainly by 1D and 2D-NMR spectrometry. Three of the new compounds ( 5 , 10 and 24 ) were evaluated for cytotoxic activities against human gastric carcinoma MGC-803, human hepatocellular carcinoma HepG2, and African green monkey kidney (VERO) cell lines in vitro . The results showed that only compound 10 showed weak cytotoxic activities on MGC-803 and HepG2 cell lines with IC 50 values at 42.90, 44.07 μM, respectively.