Extraction and identification a novel bioactive peptide from white grub larvae hydrolysate

Nowadays, bioactive peptides are considered as suitable substitutes for chemical drugs due to diversity proliferation, easy synthesis, no side effects and no accumulation in the kidneys and liver. Insects with huge diversity and success in all habitats are an appropriate source for extracting bioactive peptides. The aim of current study was to extract and purify bioactive peptide from white grub larvae hydrolysate. Bioactive peptides from white grub larvae hydrolysate were produced using papain, pancreatin, proteinase-K and trypsin. The obtained results showed that 4-hour hydrolysate of papain had the most DPPH radical scavenging (21%). This papain hydrolysate was fractionized by reverse-phase high-performance liquid chromatography (RP-HPLC). The most antioxidant fraction with the sequence of YPQSLRWRAK (1304.6 Da, named Po-1) was identified by tandem mass spectrometry. DPPH scavenging activity of synthetic Po-1 peptide at 100 µM reached to 54.41%. The IC50 value for DPPH scavenging activity of peptide was 76.45-µM. while, IC50 values natural compounds of vitamin-C and reduced glutathione (GSH) were 3.27 and 9.96 µM. In conclusion, our results showed that Po-1 bioactive peptide possesses antioxidant activity that might be used for therapeutic purposes in the future.