Triterpenes and Meroterpenes with Neuroprotective Effects from Ganoderma leucocontextum.

Ganoderma leucocontextum is a well-known medicinal mushroom cultivated in the Tibet Plateau of China. Chemistry investigation on the fruiting bodies of this mushroom resulted in the isolation of sixteen secondary metabolites including three new lanostane triterpenes, ganoleucoins Q - S (1 - 3), as well as thirteen known compounds (4 - 16). The structures of compounds 1 - 3 were determined by NMR, MS, CD spectral analysis, and chemical derivation method. The neuroprotective effects of compounds 1 - 16 were tested on PC12 cells. Compounds 1 and 2 showed protective effects against the H2 O2 induced damage with the survival rate of 83.19 ± 0.92%, 73.37 ± 1.25% at the concentration of 200 μm, respectively. Meanwhile, compounds 1 and 2 induced neurite outgrowth at 50 - 200 μm. The results from this study suggested that G. leucocontextum and its metabolites may be potential functional food ingredients for the prevention of neurodegenerative diseases.