Amino acids imprinted ZIF-8s for the highly efficient and selective adsorption of antioxidant peptides from silkworm pupa protein.

Antioxidant peptides from edible protein sources have attracted great attention due to their high activity, easy adsorption and low toxicity. The purpose of this study was to develop a new MOF material with specific recognition and capture ability to achieve the aim of highly efficient and selective antioxidant peptides from silkworm pupa protein hydrolysate-N (SPPH-N). Firstly, Histidine (His) widely presented in antioxidant peptides was used to in-suit construct the modified ZIF-8 material (ZIF-His) with imprinted defective mesopores, based on "molecular imprinting strategy". Then, it was applied to extract antioxidant peptides from SPPH-N. ZIF-His exhibited high adsorption uptake for antioxidant peptides and especially presented specific adsorption property for peptides contained His, tryptophan, phenylalanine and tyrosine. Three peptides with the highest antioxidant activity (FKVPNMY, AVNMVPFPR and VNMVPFPR) from ZIF-His eluent were identified by Nano-LC-MS/MS. These peptides were synthesized and presented the excellent free radicals scavenging activity and the Ferric reducing power.