Chemical constituents and their bioactivities from truffle Hysterangium inflatum

Abstract

Hysterangium inflatum is a truffle that grows naturally in the roots of Eucalyptus sp. and is distributed along the Mediterranean and Aegean coasts. Chemical investigation of the H. inflatum enabled to isolate of a new cerebroside, hysteroside (1), and seven known compounds namely, psyllic acid (2), brassicasterol (3), ergosterol (4), ergosterol d (5), ergosterol peroxide (6), ergosta-7,9,22-triene-3-O-β-d-glucoside (7) and mannitol (8). IR, NMR, MS techniques were used for structural elucidation and supported with literature data. Antioxidant, cholinesterase, urease, and tyrosinase inhibitory and cytotoxic activities on MCF-7 breast, H-1299 lung cancer cells, and murine fibroblast (L929) non-cancerous cells of extracts and isolated compounds from H. inflatum were analyzed. All the isolated compounds, except compounds 2 and 8, displayed considerable cytotoxic activities against MCF-7 and H-1299 cancer cells. Compounds 1 (IC50: 18.11 µg/mL) and 5 (IC50: 24.93 µg/mL) were the most effective against MCF-7, while compounds 6 (IC50: 27.61 µg/mL), 1 (IC50: 36.20 µg/mL) and 5 (IC50: 38.62 µg/mL) showed most potent toxicity against H-1299 and the extracts and compounds have no toxic effect on L929. Among the extracts, the methanol extract displayed the best antioxidant activity in all assays. Compound 1 exhibited highest enzyme inhibition activities with value of 58.71%, 52.84%, 45.37%, and 35.63%, against urease, tyrosinase, butrylcholinesterase (BChE), and acetylcholinesterase (AChE) enzymes at 100 µg/mL concentration, among the isolated compounds. These results support that H. inflatum is a steroid-rich truffle and might be a potential source, especially for ergostane type steroids.