Isolation and identification of compounds from truffle Reddellomyces westraliensis and their antioxidant, cytotoxic and enzyme inhibitory activities

Abstract

Truffles have become one of the world's most important mushrooms owing to their distinctive features. To the best of our knowledge, this is the first study on Reddellomyces westraliensis in terms of isolation and identification of compounds and screening versatile bioactivities. Chromatographic studies on R. westraliensis enabled to isolate brassicasterol (1), ergosta-7,9,22-trien-3β-ol (2), ergosterol peroxide (3), adenosine (4), D-ribitol (5), fumaric acid (6) and mannitol (7). The structures of the compounds were verified by IR, NMR, MS techniques. Antioxidant, cytotoxic and cholinesterase, tyrosinase, urease, α-amylase and α-glucosidase inhibitory activities were assessed. The methanol was the suitable extraction solvent high content of phenolic compound (18.94 ± 0.18 μg PEs/mg extract). Compound 4 showed higher DPPH• (IC50: 8.38 ± 0.40 µg/mL) and ABTS•+ (IC50: 6.74 ± 0.22 µg/mL) scavenging activity than α-tocopherol and BHA. Compound 3 was observed as a potent inhibitor against AChE (34.03 ± 0.13 %), α-amylase (34.28 ± 0.36 %) and BChE (66.31 ± 0.08 %). Compounds 1 (IC50: 5.85 ± 0.16 µg/mL) and 3 (IC50: 6.98 ± 0.24 µg/mL) indicated higher urease inhibitory activity than thiourea (IC50: 7.87 ± 0.18 µg/mL). Compounds 4 (9.61 ± 0.92 %) and 7 (21.56 ± 0.74 %) indicated higher α-glucosidase and tyrosinase inhibitory activity, respectively. Compound 2 exhibited the best cytotoxicity against H1299 (IC50: 38.62 ± 0.46 µg/mL) and MCF-7 (IC50: 24.93 ± 0.80 µg/mL). HPLC-DAD analysis exhibited the existence of fumaric acid (27.20 ± 0.06 µg/g) as the major compound. This study revealed that R. westraliensis can be approved as antioxidant, cytotoxic, and enzyme inhibitor sources in conjunction with its varied bioactive compounds.