Biodiversity of Astraeus asiaticus, a wild indigenous edible mushroom, in the forests of Bankura district, West Bengal and its antioxidant property

Three forests, Beliatore, Gangajal-ghati (G-ghati), and Joyur, were surveyed for mushroom collection and biodiversity. Mushrooms in the rhizospheric zone of some trees, such as Shorea robusta, Petrocarpus marsupium, Terminalia bellrica, and Madhuca indica, were identified at the molecular level as Asterius asiaticus. Thereafter, the ecological diversity of this mushroom was determined in the forests. The diversity indices of Shorea robusta in the Beliatore, Joypur, and Gangajal-ghati forests were 2.303, 2.178, and 2.36, respectively. Notably, the diversity index of Madhuca indica in the Beliatore and Joypur forests was nearly the same as that in the Gangajal-ghati forest, with a value of 2.29. The total phenolics contents of the hot water, acetone, and hexane extracts of this mushroom were 6.8 ± 0.15, 3.95 ± 0.15, and 2.16 ± 0.26 mg GAE/g, respectively, and the total flavonoid contents were 2.03 ± 0.12, 1.65 ± 0.2, and 1.01 ± 0.08 mg QE/g, respectively. The ascorbic acid contents in the hot water, acetone, and hexane extracts were low. The antioxidant activity of the extracts was determined using the DPPH (1,1-Diphenyl-2-picrylhydrazyl) assay. The IC50 values of the hot water, acetone, and hexane extracts were 42.54 ± 1.25c µg/ml, 54.06 ± 1.50b µg/mL, and 82.97 ± 1.58a µg/ml respectively while that of the synthetic antioxidant, BHA (butylated hydroxyanisole), was 32.41 ± 1.26d µg/mL. Overall, the hot water extract of this mushroom had the highest antioxidant content and displayed the best radical scavenging power.