Phytochemical investigation, antioxidant and anticholinesterase activities of Ganoderma adspersum

Ganoderma species are mostly used as therapeutic agents, nowadays. Some are consumed as tea, in coffee as well as dietary supplements even by the healthy people. Bioassay-guided isolation of Ganoderma adspersum (Schulz.) Donk. yielded compounds: applanoxidic acid G (1), applanoxidic acid E (2), applanoxidic acid A (3), and δ22-stigmastenol (4). Purified compounds were characterized using 1D, 2D NMR, and MS analysis. All extracts and isolated compounds were evaluated for their antioxidant and anticholinesterase activities. The antioxidant activity was performed by six methods and the anticholinesterase activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Among the extracts, the ethyl acetate extract exhibited the best antioxidant activity in all tests. It also indicated two times better BChE inhibitory activity (IC50: 19.97±1.32μg/mL) than that of galantamine. Among the compounds, compound 4 exhibited higher lipid peroxidation-inhibitory activity in β-carotene linoleic acid assay (IC50: 160.39±2.16μg/mL). Compounds 1 and 4 exhibited a moderate inhibitory activity against the BChE enzyme (IC50: 147.73±2.18 and 116.59±2.11μg/mL, respectively). The phenolic profile was analyzed by HPLC-DAD. Sixteen phenolic and organic acids were studied and seven of them detected. Fumaric and caffeic acids were identified as major phenolic acids. This paper represents the first chemical work on G. adspersum, which is a novel source of pharmaceuticals and preservatives.