Unlocking antidiabetic potential: Novel compounds from endophytic fungi isolated from Manihot esculenta Crantz tuberous roots

Penicillium oxalicum is an endophytic fungus isolated from cassava tuberous root (Manihot esculenta Crantz), and their ethyl acetate extract tested for free radicals scavenging and α-amylase, β-glucosidase enzyme inhibitory assay. The profiling of molecules from endophytic fungal extract revealed thirteen volatile and four non-volatile bioactive molecules through GC–MS and LC-MS, respectively. Notably, four molecules 2-Phenylpyrido[3,4-d]-1,3-oxazin-4-one (CID: 555,390) -9.40 kcal × mol-1, Guanosine (CID: 135,398,635) -7.60 kcal × mol-1, Quercetin-3-O-sophoroside (CID: 5282,166) -7.60 kcal × mol-1, and Esculin (CID: 5281,417) -7.20 kcal × mol-1 were identified for a better binding affinity against PPARγ protein. Molecular dynamics simulation studies predicted the Guanosine-PPARγ complex, which showed highly stable and better intermolecular interactions during the molecular dynamics simulation periods (500 ns). Further, the endophytic fungal extract showed excellent DPPH* and ABTS* scavenging and ferric ion-reducing potentials. Additionally, endophytic fungal extract displayed potential α-amylase and β-glucosidase enzyme inhibitory activities compared to pioglitazone. These findings showed that the ethyl acetate fraction of P. oxalicum is an effective source of new antioxidants and possible diabetic inhibitory properties, which can be used to generate prospective antidiabetic drugs.