Metabolomics combined to chemometrics reveals the putative α-glucosidase and α-amylase inhibitory metabolites of ground cherry (Physalis pruinosa L.)

In this work, metabolic profiling of the different parts of ground cherry (P. pruinosa) including fruits, calyces, leaves, stems and roots using UPLC-MS/MS analysis combined to chemometric analysis was attempted. A total of 82 chromatographic peaks belonging to different metabolite classes were identified including terpenes, flavonoids genin and glycosides, withanolides, physalins, sucrose esters, fatty acids and other miscellaneous compounds with withanolides being the most predominant class. Roots extracts possessed the highest relative content of the identified 5β,6β-epoxy withanolides and intermediate withanolides, while sucrose esters and flavonoidal glycosides were found in a great abundance in calyces extracts. Moreover, physalins were found in all extracts except for roots extracts. Studying the coefficients plots revealed that terpenes and physalins (physanicantriol, loliolide, physalisitin C) were responsible for discrimination of fruits extracts. Calyces, leaves and stems extracts were found to possess antioxidant activity and higher inhibition of α-glucosidase activity. In an attempt to identify the compounds responsible for the hypoglycemic activity using both α-amylase and α-glucosidase inhibition assays, OPLS models coefficient plots were constructed which indicated that physangulide B, physaperuvin G, neophysalin A, and acylsucroses were positively correlated to α-glucosidase inhibition, while guaiacyl-primeveroside, phyperunolide C, physalactone, physalolactone C and perulactone, were positively correlated to α-amylase inhibitory activity.