Metabolite profiling, antioxidant activity, and glycosidase inhibition property of the mesocarp tissue extracts of sugar date palm [Phoenix sylvestris(L.) Roxb.] fruits

Phoenix sylvestris is an underutilized seasonal fruit in West Bengal, India. Methanol extract and extracts after alkaline hydrolysis of the mesocarp tissue of full-mature edible fruits of P. sylvestris were analyzed by GC-MS following a metabolomics approach. The fractions were tested for their antioxidant and inhibitory properties against the two key enzymes involved in diabetes, α-amylase, and α-glucosidase. Total 71 metabolites belonging to organic acids, amino acids, sugars, sugar alcohols, fatty acids, and phenols were identified in the methanol extract and in fractions after saponification. All the extracts and fractions showed high antioxidant, α-glucosidase, and α-amylase inhibitory activities. Sugars like raffinose (IC50 = 0.36 μM), sucrose (IC50 = 0.51 μM), trehalose (IC50 = 0.85 μM), and phenols like taxifolin (IC50 = 0.31 μM), benzoic acid (IC50 = 2.74 μM) inhibited only the enzyme α-amylase. Phenolic components which inhibited both the enzymes were caffeic acid (IC50 = 1.42 μM for α-a...