Triterpenoid Natural Products in the Fungus Ganoderma Lucidum

Oxygenated lanostanoid triterpenes including multiple pairs of C‐3 stereoisomers and C‐3/C‐15 positional isomers were identified from the Chinese medicinal fungus Ganoderma lucidum (Fr.) Karst. Empirical rules based on the chromatographic behavior in reversed‐phase HPLC were developed to correlate the molecular polarities due to the presence of an individual functional group. 13C NMR correlation of stereochemistry in these oxygenated triterpenes was also achieved. Biosynthetic studies indicated that oxygenated triterpenes in the 3α series were derived from those in the 3β series through an oxidationreduction pathway. Several oxygenated triterpenes inhibited cholesterol synthesis in the in vitro assay. Ganodermic acid S induced platelet aggregation by stimulating the hydrolysis of phosphatidylinositol 4,5‐bisphosphate.