Cytotoxic steroids from the mushroom Ganoderma australe collected in Laos

Five steroids named stigmasterol ( 1 ), ergosterol peroxide ( 2 ), ganodertriol M ( 3 ), lucidumol B ( 4 ) and kansenone ( 5 ) were purified from the ethyl acetate extract of fruit bodies of the mushroom Ganoderma australe collected in Savannakhet province, Laos. Their structures were characterized by the combination of HR-MS, one and two dimensional NMR spectroscopic analyses. In addition, ergosterol peroxide  and kansenone showed good cytotoxicity against four cancer cell lines, KB (human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and Hep-G2 (hepatocellular carcinoma). This is the first report on the chemical constituents and cytotoxic steroids from Ganoderma sp. in Laos.