Purification and identification of antioxidant peptides from Chinese cherry (Prunus pseudocerasus Lindl.) seeds

Purification and Identification of Antioxidant Peptides from Protein Hydrolysate of Scalloped Hammerhead (Sphyrna lewini) Cartilage

“…As shown in Figure 1, the HO• scavenging activity of SHCH-I was 79.10% ± 2.38% at 15 mg protein/mL, which was significantly stronger than those of SHCH, SHCH-II, and SHCH-III ( p < 0.05). The MW of peptides plays a critical role in bioactivity, and protein hydrolysates with smaller MW usually exhibited higher antioxidant activity than larger MW hydrolysates [4,5]. SHCH-I, which is abundant in smaller MW peptides, showed high HO• scavenging activity, and the result was in agreement with other reports that the ultrafiltration fractions of protein hydrolysates with lower MW could more effectively interact with the free radicals interfering in oxidative processes [6,9].…”

“…The EC 50 values of SCPE-A, SCPE-B and SCPE-C were 0.28, 0.21, and 0.15 mg/mL, respectively, and SCPE-C exhibited the highest HO• scavenging activity. The EC 50 of SCPE-C was lower than that of PYFNK (0.24 mg/mL), LDK (0.17 mg/mL) [19,20], Leu-Gly-Leu-Asn-Gly-Asp-Asp-Val-Asn (LGLNGDDVN) (0.687 mg/mL) [34], PSYV (2.64 mg/mL) [28], HFGDPFH (0.50 mg/mL) [32], Phe-Pro-Glu-Leu-Leu-Ile (FPELLI) (0.57 mg/mL) and Val-Phe-Ala-Ala-Leu (VFAAL) (0.31 mg/mL) [4], as well as that of Tyr-Pro-Pro-Ala-Lys (YPPAK) (0.228 mg/mL) [23], Pro-Ser-Lys-Tyr-Glu-Pro-Phe-Val (PSKYEPFV) (2.86 mg/mL) [35], PYSFK (2.283 mg/mL), GFGPL (1.612 mg/mL), VGGRP (2.055 mg/mL) [30], Tyr-Leu-Gly-Ala-Lys (YLGAK) (scavenging rate: 45.14% at 0.5 mg/mL), Gly-Gly-Leu-Glu-Pro-Ile-Asn-Phe-Gln (GGLEPINFQ) (scavenging rate: 41.07% at 0.5 mg/mL) [36], Asn-Gly-Leu-Glu-Gly-Leu-Lys (NGLEGLK) (0.313 mg/mL), Asn-Ala-Asp-Phe-Gly-Leu-Asn-Gly-Leu-Glu-Gly-Leu-Ala (NADFGLNGLEGLA) (0.612 mg/mL) [32], FIMGPY (3.04), GPAGDY (3.92 mg/mL) and IVAGPQ (5.03 mg/mL) [11] from the protein hydrolysates of scalloped hammerhead muscle, conger eel, weatherfish loach, mussel sauce, Chinese cherry seeds, blue mussel, grass carp, egg white, giant squid and skate ( R. porosa ) cartilage. The three isolated peptides, especially SCPE-C, revealed good HO• scavenging activity, which demonstrated that it could serve as a scavenger to reduce or eliminate the damage induced by HO• in foods and biological systems.…”

“…SCPE-B, with an EC 50 of 0.18 mg/mL, showed the strongest scavenging activity on ABTS + • among the protein hydrolysate, fractions, and prepared peptides at all tested concentrations. The EC 50 of SCPE-B was lower than those of WDR (0.34 mg/mL) [19], LDK (0.19 mg/mL) [20], FLNEFLHV (1.548 mg/mL) [29], FPELLI (0.40 mg/mL) and VFAAL (0.38 mg/mL) [4], FLPF (1.497 mg/mL), LPF (1.013 mg/mL), LLPF (1.031 mg/mL) [33], GFGPL (0.328 mg/mL), VGGRP (0.465 mg/mL) [30], WEGPK (5.407 mg/mL), Gly-Pro-Pro (GPP) (2.472 mg/mL), GVPLT (3.124 mg/mL) [6], FIMGPY (1.04 mg/mL), GPAGDY (0.77 mg/mL) and IVAGPQ (1.29 mg/mL) [11] from the protein hydrolysates of scalloped hammerhead muscle, salmon, Chinese cherry seeds, corn gluten meal, grass carp skin, bluefin leatherjacket heads and skate cartilage. The present results indicated that SCPE-A, SCPE-B and SCPE-C could strongly donate electrons or hydrogen atoms to inactivate ABTS + •.…”

“…Huang et al (2005) reported that amino acids with aromatic residues, such as Phe, Tyr and Trp, can quench free radicals by direct electron transfer [46]. The results from Guo et al (2015) indicated that hydrophobic amino acids (e.g., Val, Ala, Leu) and aromatic amino acids (Phe, His, Tyr and Trp) can enhance the radical-scavenging abilities of peptides from Chinese cherry seeds [4]. Therefore, the presence of the one Ala residue and two Phe residues in the sequences of SCPE-B and SCPE-C, respectively, should have a positive impact on their radical-scavenging and lipid peroxidation inhibitory activities.…”

“…Therefore, the inhibition of free radical formation and oxidation reactions play an important role in preventing or retarding the autoxidation of food components [3]. Many synthetic antioxidants, including butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tertiary butylhydroquinone (TBHQ), are widely used in the food industry for preservation and to retard lipid oxidation [4,5]. However, the dosages of the synthetic antioxidants are under strict regulation due to their potential health hazards and toxic effects [6,7].…”