Studies On The Preparation And Physiological Activity Of High F Value Of Corn Oligopeptides-Zinc,Selenium Chelate

The high F value of corn oligopeptide obtained by complex enzymatic hydrolysis of Corn processing by-products of corn gluten meal not only has many biological activities,but also promotes the absorption of trace elements zinc and selenium in the body.In this paper,high F value of corn oligopeptide and zinc sulfate and sodium selenite were used as raw materials to prepare high F value of corn oligopeptide-zinc and selenium chelate compounds.The chelates were isolated and purified and their structures were identified.Finally,the effects of zinc supplement and selenium supplementation,antioxidant and anti-alcohol & liver-protection activity of chelates was studied.The optimal conditions for high F value of corn oligopeptide-zinc chelating reaction were determined by single factor experiment and response surface design.The results showed that the optimal conditions were as follows: the molar ratio of peptide and zinc was 2.08:1,the pH was 6.08,the temperature was 60.58 ?,and the reaction time was 40 min.The chelating rate of zinc was 77.90% under the optimum conditions.The purity of the chelate was 77.98 %.The zinc chelate with high F value of corn oligopeptide was determined the molecular weight and analyzed component by Sephadex G-15 and C-18 reversed-phase high performance liquid chromatography: The molecular weight of the high F-value of corn oligopeptide-zinc chelate is about 337 and the component P-Zn3 a and the component P-Zn3 b were obtained.The structure of the chelate was studied by UV absorption spectroscopy,infrared absorption spectroscopy and electrospray ionization mass spectrometry.The results of UV wavelength scanning showed that the maximum absorption wavelength of zinc sulfate was 192 nm,the maximum absorption wavelength of corn oligopeptides was 220 nm,and the maximum absorption wavelength of high F value of corn oligopeptide-zinc chelate was 209 nm.The components were sequenced with MALDI-TOF/TOF MS/MS,and the amino acid sequences were Gly-Val-Leu(Ile)and Met-Leu(Ile).The infrared spectrum of the structure indicated that the chelating mechanism of corn oligopeptide and zinc ion was as follows: the position of chelation with Zn2+ may be-NH on-NH-C=O of oligopeptide,while-OH on-COOH and terminal-NH2 of oligopeptide.It can be inferred that high F value of corn oligopeptides chela ted with zinc and a new type of chelate was produced.The mice were fed with zinc deficient diet and the zinc deficiency model was successfully constructed.Zinc deficiency can cause loss of appetite in mice and inhibit its growth and development.At the same time,the content of liver zinc and serum zinc and alkaline phosphatase activity were reduced.After 20 d zinc supplement,the diet returned to normal and activities were in good condition.In the case of the same dose of zinc supplementation,the bioavailability of the high F value of corn oligopeptide-zinc chelate group was the highest,followed by the zinc glycine group and the zinc gluconate group,and the lowest bioavailability was the zinc sulfate group.The high F value of corn oligopeptidezinc chelate can significantly increase the content of liver zinc and serum zinc in mouse and also significantly improve the activity of alkaline phosphatase.This suggested that high F value of corn oligopeptide-zinc chelate was a good zinc supplement.Compared with the zinc deficiency group,the high F value of corn oligopeptide-zinc chelate group significantly reduced the MDA content,significantly increased the total antioxidant capacity,and significantly enhanced the SOD activity,which indicated that the high F value of corn oligopeptide-zinc chelate had significant antioxidant activity and was a good antioxidant.Compared with the control group,the high F value of corn oligopeptide-zinc chelate group significantly shortened the soaking time in mice and significantly decreased the activity of ALT and AST,which indicated that the high F value of corn oligopeptide-zinc chelate has the activity of anti-alcohol & liver-protection.The optimal conditions for high F value of corn oligopeptide-selenium chelating reaction were determined by single factor experiment and response surface design.The results showed that the optimal conditions were as follows: the quality ratio of peptide and selenium was 1.17:1,the pH was 7.22,the temperature was 70.28 ?,the peptide concentration was 5 %,and the reaction time was 60 min.The chelating rate of selenium was 56.81 % under the optimum conditions.The purity of the chelate was 71.13 %.The selenium chelate with high F value of corn oligopeptide was determined the molecular weight and analyzed component by Sephadex G-15 and C-18 reversed-phase high performance liquid chromatography: The molecular weight of the high F-value of corn oligopeptide-zinc chelate is about 348 and the component P-Se3 a and the component P-Se3 b were obtained.The structure of the chelate was studied by UV absorption spectroscopy,electrospray ionization mass spectrometry and infrared absorption spectroscopy.The results of UV wavelength scanning showed that the high F value of corn oligopeptide-selenium chelate exhibited a new absorption peak near the wavelength of 232 nm and the absorbance intensity and the position were different from the high F value of corn oligopeptide.The components were sequenced with MALDI-TOF/TOF MS/MS,and the amino acid sequences were Gly-Val-Leu(Ile)and Met-Leu(Ile).The infrared spectrum of the structure indicated that the chelating mechanism of corn oligopeptide and selenium ion was as follows: the position of chelation with selenium ion may be-NH on-NH-C=O of oligopeptide,while-OH on-COOH and terminal-NH2 of oligopeptide.It can be inferred that high F value of corn oligopeptides chelated with selenium and a new type of chelate was produced.The mice were fed with selenium deficient diet and the selenium deficiency model was successfully constructed.Lack of selenium can reduce the appetite of mice,make the fur messy,and inhibit its growth and development.While the liver selenium and serum selenium content were reduced.After 20 d selenium supplement,the diet returned to normal and the phenomenon of fur clutter was improved.In the case of the same dose of selenium supplementation,the bioavailability of the high F value of corn oligopeptide-selenium chelate group was the highest,followed by the methionine selenium group,and the lowest bioavailability was the sodium selenite group.The high F value of corn oligopeptideselenium chelate can significantly increase the content of liver zinc and serum zinc in mouse.This suggested that high F value of corn oligopeptide-selenium chelate was a good selenium supplement.Compared with the selenium deficiency group,the high F value of corn oligopeptide-selenium chelate group significantly reduced the MDA content,significantly increased the total antioxidant capacity,and significantly enhanced the SOD activity,which indicated that the high F value of corn oligopeptide-selenium chelate had significant antioxidant activity and was a good antioxidant.Compared with the control group,the high F value of corn oligopeptide-selenium chelate group significantly shortened the soaking time in mice and significantly decreased the activity of ALT and AST,which indicated that the high F value of corn oligopeptide-selenium chelate has the activity of anti-alcohol & liver-protection.