Isolation and Identification of Three Novel Antioxidant Peptides from the Bactrian Camel Milk Hydrolysates

The aim of this study was isolation and purification of antioxidant peptides from Bactrian camel milk (BCM) hydrolysate. Trypsin, pepsin, alcalase, and papain were used for hydrolysis of BCM. The peptides fraction from trypsin digest exhibited a strong antioxidant activity among them, and it was separated by ultrafiltration (3000 Da membrane). The resulting peptides (< 3000 Da) were further separated with using gel filtration chromatography (HW-55F) and reverse-phase high-performance liquid chromatography (RP-HPLC). Three novel antioxidant peptides were purified and sequenced by MALDI TOF-MS/MS as RLDGQGRPRVWLGR (TFI-b1), TPDNIDIWLGGIAEPQVKR (TFI-b2) and VAYSDDGENWTEYRDQGAVEGK (TFI-b3) with molecular weights 1665.94, 2122.13, and 2489.09 Da, respectively. The IC50 values of these peptides on DPPH were 1.9, 1.2 and 0.6 mg/mL and on ABTS are 2.4, 1.8 and 0.9 mg/mL, respectively. The peptides identified using similarity search tool of SIB ExPASy Bioinformatics Resources Portal ().