Production and qualitative analysis of triterpenoids and steroids of Ganoderma species harvested from cork oak forest of North-Eastern Algeria

Abstract

Submerged fermentation of higher fungi Ganoderma is increasingly, studied for its potential advantages particularly, improving the production biomass and bioactive metabolites. The present study mainly focuses on the qualitative assessment of triterpenoids and steroids in chloroform extracts of harvested mycelia from submerged cultures of three different strains of Ganoderma sp. by using a low cost complex medium. For the screening of these bioactive substances we employed a High Performance Liquid Chromatography (HPLC) system based on a gradient of acetonitrile acidified with formic acid, coupled to a Quadrupole Time-of-Flight Mass Spectrometer (QToF-MS) for a tentative determination of Ganoderic Acids (GA) and sterols. The LC-QToF-MS approach was successfully, used in the qualitative analysis of bioactive metabolites. The results show a considerable diversity of produced metabolites in the three samples and indicate the presence of putative target components, such as; GAA, GAH, GA theta, GA beta, GAK, GAE, GAC2, GAR, GAX and ergosterol. The comparison of the compounds according to their retention time and QToF-MS spectra reveals nine shared metabolites produced by the three different strains of Ganoderma sp., GAAm1, GAY, GAS, GAT-Q and GAT.