15 results about "ABTS" patented technology

This invention discloses a method for detecting antioxidants (AA) in solution using a redox sensor. Belonging to the field of detection applications, the method is as follows: An ABTS solution, a test solution containing AA, and a silver nanoparticle solution with oxidase-like activity are mixed thoroughly. An acidic solution is added to adjust the pH of the system, and the reaction is allowed to proceed for 2-3 hours. SERS detection is then performed under 532nm laser irradiation to measure the Raman peak value of the sample. AA is qualitatively detected by comparing the changes in the Raman peak value of the blank sample with that of the sample. This invention achieves accurate and inexpensive trace detection of AA by comparing the differences in the degree to which different concentrations of AA inhibit the oxidation of ABTS by oxidase-like enzymes with the reaction system without the addition of the antioxidant AA. The reaction system for detecting antioxidants explored in this invention, utilizing SERS technology for trace detection of the antioxidant AA, has significant implications for practical applications.

The present application relates to the technical field of chemical preparations, in particular to a method for improving the bioavailability of astaxanthin in phaffia rhodozyma powder and application. The present application uses composite enzymes to pretreat phaffia rhodozyma powder, so that astaxanthin is fully released from the cells, and then specially-made eutectic solvent is used to efficiently extract the pretreated phaffia rhodozyma powder, and the extraction rate can reach more than 90%. The astaxanthin extract prepared by the present application has high antioxidant activity and high bioavailability, and the DPPH free radical scavenging rate can be up to 89.14%, the ABTS free radical scavenging rate can be up to 90.09%, and the bioavailability can be up to 81.41%. In addition, the present application is simple to operate, does not need ultrasonic, microwave and other assisted methods, has low requirements on equipment, can be suitable for industrial large-scale production, provides a feasible scheme for the green and efficient extraction of astaxanthin, and has a wide application prospect in the food, cosmetic and feed industries.

The invention discloses a polypeptide with antioxidant activity and application thereof, and belongs to the technical field of biological medicine and fine chemical engineering. The amino acid sequence of the polypeptide is selected from QY, YG, YYYY, QPYY or WHYHDYKY. HPLC and MS structure confirmation shows that the synthesized polypeptide is high in purity and accurate in structure. In-vitro chemical experiments prove that the polypeptide (especially WHYHDYKY) has extremely high ABTS and DPPH free radical scavenging capacity, and the activity of the polypeptide is superior to or equal to that of glutathione (GSH). Cell experiments show that part of polypeptides (such as QY, YG, YYYY and QPYY) can significantly improve the survival rate of HepG2 cells under an oxidative damage model, and have a significant cell protection function. The polypeptide can be applied to the fields of antioxidant drugs, functional food, cosmetics, industrial antioxidants and the like according to the characteristics of the polypeptide.

The invention discloses a fish-derived active peptide with antioxidant and hypoglycemic effects, a preparation and application, and belongs to the technical field of biological active peptides. The fish-derived active peptide with the effects of resisting oxidation and reducing blood sugar is at least one of peptide fragments with amino acid sequences as shown in SEQ ID NO: 1-SEQ ID NO: 3. According to the invention, three active peptides with antioxidant and hypoglycemic effects are extracted from salmon by-products by adopting protease enzymolysis, LC-MS / MS, a bioinformatics method and other methods, and the active peptides have high DPPH clearance rate, ABTS free radical clearance rate and alpha-glucosidase and alpha-amylase inhibition rate. Therefore, the compound has an important application prospect in the development of products with the effects of resisting oxidation and reducing blood sugar.

The invention discloses a hesperetin derivative containing a thiosemicarbazone structure and application of the hesperetin derivative, the molecular formula of the compound is C18H19N3O5S, the biological activity determination result shows that the compound has good anti-oxidation and anti-alpha-glucosidase activity, the IC50 value of DPPH scavenging activity is 6.17 mu g / mL, and the activity of the hesperetin derivative is equivalent to that of a control agent vitamin C. The hesperetin derivative containing the thiosemicarbazone structure and the application of the hesperetin derivative containing the thiosemicarbazone structure have good anti-oxidation and anti-alpha-glucosidase activity. The IC50 value of ABTS clearance activity is 0.04 mu g / mL, and the activity is improved by 200 times compared with that of a control medicament vitamin E; the IC50 value of the alpha-glucosidase inhibitory activity is 4.53 [mu] g / mL, which is improved by 51 times compared with the activity of a control agent acarbose; the structural formula of the hesperetin derivative containing the thiosemicarbazone structure is shown in the specification.

The application discloses a kind of polypeptide with antioxidant activity and application thereof, belong to biological medicine and fine chemical technology field.The amino acid sequence of the polypeptide is selected from QY, YG, YYYY, QPYY or WHYHDYKY.HPLC and MS structure confirmation, synthetic polypeptide is high in purity, accurate in structure.In vitro chemical experiment confirms that the polypeptide (especially WHYHDYKY) has very strong ABTS and DPPH free radical scavenging capacity, and the activity is better than or equivalent to glutathione (GSH).Cell experiment shows that part of polypeptide (such as QY, YG, YYYY, QPYY) can significantly improve the survival rate of HepG2 cell under oxidative damage model, and has significant cell protection function.The polypeptide of the application can be applied in the field of antioxidant drugs, functional food, cosmetics and industrial antioxidants, etc.

The invention discloses an enhanced colorimetric method for rapidly and selectively detecting glutathione and a kit thereof, and belongs to the technical field of biochemical detection. The method comprises the following steps: preparing a prussian blue solution, a Turnish blue solution, a ferrous chloride solution or a ferric chloride solution as a nano-enzyme catalysis solution; mixing the catalytic solution with an ABTS solution and a hydrogen peroxide solution according to a specific proportion to form a blank reaction solution; adding a glutathione-containing to-be-detected sample into the solution to carry out a chromogenic reaction; and determining the content of glutathione by determining the absorbance difference between the blank and the reaction solution to be detected in a specific wavelength range. The method is mainly used for rapid, selective and quantitative detection of glutathione in the fields of food, medicine and biological analysis.

The invention belongs to the field of phytochemistry and medicines, and discloses an antioxidant active ingredient, namely, indole amide glycoside Portulaleramides A-U from Portulaleralea L., and a preparation method of the indole amide glycoside Portulaleramides A-U, wherein the indole amide glycoside Portulaleramides A-U is prepared from Portulalea L.. The invention also relates to a herba portulacae active component with antioxidant activity. According to the present invention, the indole amide glycoside Portulamides A-U can scavenge free radicals ABTS and DPPH, and the Portulamides N can reduce the level of intracellular reactive oxygen species (ROS) so as to provide a significant protection effect on t-BHP induced oxidative damage, such that the indole amide glycoside Portulamides A-U can provide significant protection effects for the t-BHP induced oxidative damage, and can provide significant protection effects for the t-BHP induced oxidative damage,

The invention belongs to the technical field of food science and bioengineering, and provides a method for improving antioxidant and hypoglycemic activity of bovine bone enzymatic hydrolysate. The method comprises the following steps: performing ultrasonic pretreatment on cattle bone powder (500W, 30min), performing alkaline protease hydrolysis (50 DEG C, 5h), mixing the inactivated cattle bone powder with D-xylose (8: 1), and performing Maillard reaction (100 DEG C, 120min). The DPPH free radical scavenging rate and the ABTS free radical scavenging rate of the obtained product respectively reach 91% and 88.13%, and the antioxidant activity is remarkably improved; the synthetic peptide, such as FGFDGDFYR, has both the hydroxyl radical scavenging rate of 74.52% and the alpha-glucamylase inhibition rate of 70.2%, so that the double-function activity of resisting oxidation and reducing blood sugar is realized; meanwhile, the product is enhanced in palatable taste and reduced in bitter taste, is rich in meat flavor compounds (such as 2-methyl-3-furanmercaptan), has flavor and functional advantages, and promotes high-value utilization of bovine bones.

The present application relates to a kind of soybean polypeptide preparation method with antioxidant and antagonistic lead damage effect.The soybean polypeptide prepared in the present application has good DPPH free radical clearance rate, ABTS free radical clearance rate and Fe3+ reduction capacity in vitro;It can also alleviate the case that the body weight of mouse is slowly increased due to lead exposure, improve the learning and memory ability of lead exposure mouse, alleviate the organ damage of mouse caused by lead exposure, enhance the level of reduced glutathione, superoxide dismutase and catalase of organism, and alleviate the abnormal increase of malondialdehyde caused by lead exposure.The soybean polypeptide prepared in the present application has good in vitro antioxidant capacity, and has antagonistic effect on oxidative stress caused by lead exposure mouse, and can be used as non-toxic and harmless natural antioxidant.For the development of natural antioxidant food, it has far-reaching application prospect, and also provides a new feasible idea for the combined application of bioinformatics technology and traditional enzymatic technology.

The invention provides a preparation and screening method of royal jelly source antioxidant peptide based on in-vitro simulated digestion. The sequence of the antioxidant peptide is as shown in SEQ. ID. NO.1: FNYDPRY (recorded as P1). The method comprises the following steps: carrying out static in-vitro simulated digestion on MRJPs to obtain products at different digestion stages, carrying out polypeptide sequence identification by combining liquid chromatography-tandem mass spectrometry (LC-MS / MS), and further carrying out antioxidant activity prediction and safety evaluation on the identified polypeptide by utilizing bioinformatics, so as to obtain a plurality of candidate polypeptides; the candidate peptides are subjected to in-vitro antioxidant activity detection and comprehensive screening by adopting a DPPH method, an ABTS method and an FRAP method, and P1 in the screened candidate peptides is optimal under three in-vitro evaluation systems of the DPPH method, the ABTS method and the FRAP method. The antioxidant peptide can be used for preparing antioxidant functional food, health food, medicine or cosmetic compositions.

The invention discloses a green modification preparation method of AX with high viscosity and antioxidant activity, which comprises the following steps: adding EDC and NHS into an AX solution for esterification reaction, then adding cysteine for grafting, dialyzing and freeze-drying to obtain modified AX. According to the invention, Cys is successfully grafted to carboxyl of a side chain of AX through amidation reaction, so that thiolation modification of AX is successfully completed. Only 15.71%-18.75% of sulfydryl in the TAX subjected to thiolation modification is oxidized to generate a disulfide bond, and the biological activity of the sulfydryl is well reserved. Sulfydryl introduced through thiolation modification endows TAX with excellent oxidation resistance and adhesion property, and compared with TAX before modification, DPPH (1, 1-diphenyl-2-picrylhydrazyl) and ABTS (2, 2 '-azinobis (2, 3-azinobis (3, 4-azinobis (3, 4-azinobis (3, 4-azinobis (3, 4-azinobis (3,

This invention discloses a multifunctional peptide derived from bovine serum albumin, possessing antioxidant, hypoglycemic, and tyrosinase-inhibiting properties, as well as its preparation and applications, belonging to the fields of food, biopharmaceutical, and cosmetic technologies. This invention screened and verified a novel multifunctional peptide, SFLYEYSRR, with a defined sequence. SFLYEYSRR exhibits a maximum ABTS scavenging rate of 89.93%, a maximum DPPH free radical scavenging rate of 35.48%, a maximum hydroxyl free radical scavenging rate of 46.49%, an α-glucosidase inhibition rate of 64.36%, and a maximum tyrosinase inhibition activity of 48.33%, overcoming the limitations of existing single-functional peptides in application.

The invention discloses a rapid grinding preparation method of benzoic acid-nicotinamide eutectic and a new application of the benzoic acid-nicotinamide eutectic in the fields of antibiosis and antioxidation. The eutectic is prepared by adopting a liquid-assisted mechanical grinding method, specifically, benzoic acid and nicotinamide in a molar ratio of 1: 1 are firstly subjected to dry grinding, then acetonitrile in a specific proportion is added for wet grinding to form paste, and then the eutectic is obtained by drying. The method is green, rapid and efficient in process. The prepared co-crystal shows unexpected synergistic biological activity; the antibacterial effect of the co-crystal on escherichia coli and staphylococcus aureus is obviously superior to that of each component monomer and a physical mixture; meanwhile, in DPPH and ABTS free radical scavenging experiments, a synergistic anti-oxidation effect is also shown. The eutectic crystal can be used as a high-efficiency antibacterial agent and an antioxidant, and has a wide application prospect in the fields of food preservation and medicine.

The invention relates to the identification of the Populus ciliata tree bark as a natural antioxidant and with potential antimicrobial activities. Crude methanol bark extract and its fractions (ethyl acetate, n-butanol, chloroform and n-hexane) were screened for antioxidant analysis and antimicrobial activities against gram positive (B. subtilis, S. aureus) and gram negative (E. coli, P. aeruginosa and K. pneumoniae) bacteria. Results of DPPH, ABTS and FRAP assays revealed the highest antioxidant potential of n-butanol and ethyl acetate fractions with lower IC50 value as compared to standard ascorbic acid, crude methanol extract and others fractions. Total phenolic content and total flavonoids content were also observed to be higher in n-butanol fraction (317.83±2.95 mg / g gallic acid and 271.26±0.89 mg / g quercetin, respectively) followed by ethyl acetate fraction, than crude methanol extract, chloroform and hexane fractions of bark indicating the highest antioxidant potential of P. ciliata bark extracts. Antibacterial assay also showed higher zone of inhibition of n-butanol and ethyl acetate fractions of P. ciliata bark against gram positive and gram negative bacteria, later on supported by the lower MIC value (62.5µg / ml) of both fractions. Present invention concluded P. ciliata tree bark as higher antioxidant and antibacterial potential agent whose n-butanol and ethyl acetate fraction was observed to be more effective than crude extract alone. This work further includes the extraction and identification of compounds with higher biological activities (antioxidant and antifungal activities) which would be further helpful in decreasing the pressure of pharmaceutical companies on wild herbaceous medicinal plants.