52 results about "ABTS" patented technology

The invention discloses a method for detecting glufosinate-ammonium residues in coffee in dual modes of colorimetry and chemiluminescence, and belongs to the technical field of chemical analysis and detection.The method comprises the steps that Schiff base formed by 4-aminoantipyrine and glutaraldehyde serves as a complexing agent of Cu < 2 + >, and then a copper-doped carbon dot Cu-CDs nano-enzyme is prepared through microwave digestion; according to the present invention, the Cu-CDs nano-enzyme has excellent peroxidase-like activity, can oxidize the colorless 2, 2 '-biazo-bis-3-ethylbenzothiazoline-6-sulfonic acid into the blue-green oxidized ABTS, and can improve the chemiluminescence intensity of the reaction of N-(4-aminobutyl)-N-ethylisoluminol and H2O2 by nearly 100 times when the Cu-CDs nano-enzyme is used as the chemiluminescence catalyst; based on the inhibition effect of glufosinate-ammonium on the activity of Cu-CDs POD, a sensitive and rapid colorimetric and chemiluminescence two-channel GM detection technology is developed, and the method has potential application value in the aspect of coffee safety monitoring.

The invention relates to laccase as well as a mutant and application thereof, and belongs to the technical field of biology. The amino acid sequence of the laccase PnLac1 is as shown in SEQ ID NO. 2, and the nucleotide sequence of the laccase PnLac1 is as shown in SEQ ID NO. 1. The mutant is characterized in that aspartic acid at the 166th position of laccase PnLac1 is subjected to site-specific mutagenesis, histidine at the 348th position of laccase PnLac1 is subjected to site-specific mutagenesis, methionine at the 403th position of laccase PnLac1 is subjected to site-specific mutagenesis, or leucine at the 467th position of laccase PnLac1 is subjected to site-specific mutagenesis, amino acid sequences are shown as SEQ ID NO.4, SEQ ID NO.6, SEQ ID NO.8 and SEQ ID NO.10, and nucleotide sequences are shown as SEQ ID NO.3, SEQ ID NO.5, SEQ ID NO.7 and SEQ ID NO.9. The decoloring efficiency of the laccase PnLac1 on crystal violet reaches 5h, and the degradation rate reaches 75%. When the ABTS is used as a substrate, the enzyme activities of the laccase mutants H348F and L467M are respectively improved by 1.89 times and 1.65 times, and the ABTS has the potential of degrading stubborn substances; when guaiacol is used as a substrate, the enzyme activities of the laccase mutants D166A and M403F are respectively improved by 2.07 times and 3.72 times, and the guaiacol has a relatively high application prospect in the field of lignin.

The invention relates to the technical field of bioactive peptides, in particular to an antioxidant peptide based on mussel byssus, a preparation method, a preparation and application of the antioxidant peptide based on mussel byssus, the antioxidant peptide is designed and synthesized by referring to the structural characteristics of mussel byssus proteins mfp-3, mfp-5 and mfp-6, the antioxidant peptide comprises four sequences of MFP3-AP1, MFP5-AP2, MFP6-AP3 and MFP-Hybrid, tyrosine in the peptide is modified into DOPA through enzymatic modification, and the antioxidant peptide is prepared through enzymatic modification. The stability and activity of the antioxidant peptide are enhanced through disulfide bond formation, metal ion coordination, PEGylation and other modifications, and the antioxidant peptide has high DPPH free radical scavenging activity, ABTS free radical scavenging activity, hydroxyl free radical scavenging activity and iron ion reducing capacity, has a protective effect on the cellular level, can be prepared into a liquid preparation, a freeze-dried preparation or a micro-capsule preparation, and can be used for preparing the antioxidant peptide. The compound is expected to be applied to the fields of antioxidant health care products, cosmetics and medicines.

The invention provides a preparation method of collagen and an application of the collagen in anti-aging. According to the invention, the anti-aging antioxidant collagen peptide F-5-B is obtained through enzymolysis and column separation identification. It is identified that the polypeptide has good DPPH free radical scavenging capacity, ABTS free radical scavenging capacity and lipid peroxidation reaction inhibiting capacity, the collagen peptide F-5-B can further inhibit melanoma cells from synthesizing melanin, and the polypeptide can further obviously increase the SOD level in the liver of a mouse. SOD can help the body resist attack of free radicals, so that the aging process is slowed down. Therefore, the anti-aging pharmaceutical composition prepared from the polypeptide has a relatively good application prospect.

The invention discloses a method for improving in-vivo and in-vitro antioxidant activity of pomegranate peel polyphenol extract through combined enzymolysis of tannase and beta-glucosidase, and relates to the technical field of food science and biology. The pomegranate peel polyphenol extract provided by the invention is obtained from pomegranate peel powder through solvent extraction. According to the present invention, tannase and beta-glucosidase are adopted to perform single or combined enzymolysis on the pomegranate peel polyphenol extract, and the determination on the in vitro antioxidant activity of the pomegranate peel polyphenol extract shows that the antioxidant activities of DPPH and ABTS after the combined enzymolysis are improved by 29.84% and 29.30% compared with the antioxidant activities of the untreated polyphenol extract; the UPLC-ESI-QTOF-MS is used for identifying and analyzing the components of the enzymatic hydrolysate, the content of macromolecular ellagic tannin is obviously reduced, and the content of micromolecular ellagic acid and gallic acid is increased. The enzymolysis polyphenol is applied to D-galactose induced oxidative stress mice, and the result shows that the oxidative damage relieving effect of the enzymolysis polyphenol on the mice is better than that of untreated polyphenol.

The invention belongs to the technical field of biological medicines, and particularly relates to coumarin hydrazone derivatives with antioxidant activity and application thereof. The chemical structural formula of the coumarin derivative is as shown in formula (I), wherein R is aromatic rings containing different substituent groups. An in-vitro anti-oxidation experiment result shows that most of the derivatives have certain scavenging capacity on free radicals such as DPPH, ABTS, superoxide anions and hydroxyl and have certain reducing capacity. It is worthy of noting that the scavenging effect of the derivatives 5a-5d, 5i-5k, 5m and 5n on superoxide anion free radicals is superior to or equivalent to that of vitamin C. The method for preparing the coumarin hydrazone derivative has the advantages of simplicity in operation, convenience in post-treatment, high product separation yield and the like. The coumarin compound can be used for preparing an antioxidant. # imgabs0 #

The invention belongs to the technical field of medicine detection, and particularly relates to a rapid detection method for antioxidant activity of dendrobium officinale medicinal materials and application of the method, and the method comprises the following steps: (1) collecting a plurality of batches of dendrobium officinale medicinal materials and crushing; (2) obtaining ABTS free radical scavenging rate, iron ion reducing capacity and DPPH free radical scavenging rate in the dendrobium officinale sample through a chemometrics method; (3) collecting the near-infrared original spectrum of the dendrobium officinale medicinal material; (4) after abnormal spectrums are removed, processing original near infrared spectrums by a standard normal variable transformation spectrum preprocessing method, and dividing a correction set and a verification set by adopting a KS algorithm to establish a partial least square regression model; the near infrared spectrum technology is adopted to detect the antioxidant activity of the dendrobium officinale medicinal material, the method has the advantages of being easy to operate, rapid, free of damage and high in precision, production cost can be saved, economic benefits can be improved, and the purpose of efficient quality control can be achieved on the traditional Chinese medicine production source.

The invention provides a V2O5-NC nano-enzyme as well as preparation and application thereof. The V2O5-NC nano-enzyme is dark green powder and has a stacked layered structure, the specific surface area is 16-18m < 2 > / g, mesoporous distribution is realized, the average particle size is 20-25nm, and the V2O5-NC nano-enzyme has catalase-like activity. The wide-interlayer-spacing V2O5-NC nano-enzyme based on C-O bond bridging prepared by the invention has relatively good stability, can be prepared on a large scale, is convenient to store, has good affinity to catalytic chromogenic substrates, has high stability, and has universality for the chromogenic reaction of the catalytic chromogenic substrates (TMB, ABTS, DAB and OPD). The V2O5-NC nano-enzyme disclosed by the invention is used for analyzing five organophosphorus pesticides (parathion-methyl, glyphosate, phoxim, methamidophos and chlorpyrifos), has good pesticide recognition capability and interference resistance, and also has the advantages of wide linear range, low detection limit, simplicity and convenience in operation, low detection cost and the like.

The invention relates to the technical field of analytical chemistry and food pharmacy detection, in particular to a rutin antioxidant activity colorimetric determination method based on a composite nano enzyme, which comprises the following steps: mixing a to-be-detected sample solution with an ABTS free radical cation working solution to carry out first reaction, so that an antioxidant substance in a sample and ABTS free radical cations are subjected to scavenging reaction; adding the composite nano enzyme, a 3, 3 ', 5, 5'-tetramethyl benzidine solution and a hydrogen peroxide solution into a system after the first reaction is completed, and initiating a second reaction; and measuring the absorbance value of the system after the second reaction under a specific wavelength, comparing the absorbance value with the standard curve obtained through the treatment in the same step, and calculating the antioxidant activity expressed by the equivalent concentration of rutin in the sample to be detected. By optimizing reaction conditions, the method provided by the invention simplifies operation steps and can provide accurate measurement results in a wider concentration range.

The invention belongs to the technical field of biology, and particularly relates to a novel antioxidant peptide and application thereof, and the amino acid sequence of the novel antioxidant peptide is shown as SEQ ID NO.1. The antioxidant peptide is high in biological activity, has relatively high scavenging capacity on DPPH. Free radicals and ABTS. Free radicals, has relatively high reducing capacity on Fe < 3 + >, and has wide application in the aspects of preparing antioxidant medicines, foods or cosmetics and the like. Meanwhile, the antioxidant peptide is short in sequence, easy to synthesize and suitable for large-scale production and application.

The invention discloses an eggshell membrane source antioxidant umami peptide and application thereof, the amino acid sequence of the eggshell membrane source umami peptide is at least one of CDDDF, CWDVYR and WHDCHR, and relates to the technical field of bioactive peptides. The eggshell membrane umami peptides with antioxidant activity are screened by using a method of combining virtual enzymolysis, machine learning, molecular docking and molecular dynamics simulation, and three eggshell membrane umami peptides are screened and can be combined with umami receptor T1R1 / T1R3 subunits, and the composite conformation is stable. Sensory evaluation and electronic tongue analysis prove that the eggshell membrane source antioxidant umami peptide has good umami characteristics, the umami threshold value is 0.04-0.10 mmol / L, the eggshell membrane source antioxidant umami peptide has DPPH free radical scavenging capacity, ABTS + free radical scavenging capacity and Fe < 3 + > reduction activity, a new raw material is provided for development of functional seasonings, and the eggshell membrane source antioxidant umami peptide has important application value.

The invention discloses an extraction process for optimizing general flavone of strobilanthes cusia through a response surface method. An ultrasonic extraction method is adopted to extract total flavonoids in strobilanthes cusia, on the basis of a single factor experiment, an extraction process of the strobilanthes cusia total flavonoids is optimized through a response surface method, and comprehensive experiment conditions, operability and rationality are considered, so that the optimal extraction process is obtained as follows: the material-liquid ratio is 1: 27, the ethanol concentration is 72%, the ultrasonic extraction time is 39 min, and the extraction time is 30 min; under the condition, the total flavone extraction rate reaches 0.736 + / -0.015% and is basically consistent with a response predicted value. The extraction process is simple and stable in operation and high in extraction rate. In-vitro anti-oxidation experiments show that the strobilanthes cusia total flavonoids have certain DPPH free radical and ABTS free radical scavenging capacity, and a reference basis is provided for more fully and reasonably utilizing strobilanthes cusia resources.

The invention discloses a pyrimidine derivative containing a thiosemicarbazide structure and application of the pyrimidine derivative, and relates to the technical field of medicines, the compound has good oxidation resistance and alpha-glucosidase resistance activity, and the compound is 2-(4, 4 '-difluorophenyl)-2-(4, 4'-difluorophenyl)-2-(4, 4 '-difluorophenyl)-2-(4, 4' The IC50 values of the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide on DPPH (1, 1-diphenyl-2-picrylhydrazyl) scavenging activity and ABTS (2, 2, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide are 3.96 mu g / mL and 2.01 mu g / mL respectively, the IC50 value of the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide on alpha-glucosidase inhibitory activity is 38.62 mu g / mL, the effect is best, and the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1 The pyrimidine derivative containing the thiosemicarbazide structure has a general formula shown in the specification, and is superior to control medicaments such as vitamin C, vitamin E and acarbose.

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.

A novel polypeptide with double biological activities is obtained from sea cucumber intestines, and the sequence of the polypeptide is KADANNQWVDVK through high performance liquid chromatography purification and mass spectrometry analysis and identification. The in-vitro activity evaluation of a system shows that the polypeptide not only shows remarkable antioxidant capacity and can effectively remove ABTS free radicals, but also shows relatively strong pancreatic lipase inhibitory activity, and the IC50 value of the polypeptide reaches a remarkable level. The marine active peptide with double functions of oxidation resistance and metabolism regulation shows a good application prospect in the field of functional food and medicine development. The sea cucumber intestines are treated through an enzymolysis technology, low-molecular-weight polypeptides are separated through dialysis, de novo sequencing is carried out, and high-throughput polypeptides are synthesized. The polypeptide KADANNQWVDVK (lysine-alanine-aspartic acid-alanine-asparagine-asparagine-glutamine-tryptophan-valine-asparagine-valine-lysine) with the activity of resisting oxidation and inhibiting pancreatic lipase is screened, and the polypeptide KADANNQWVDVK (lysine-alanine-aspartic acid-alanine-asparagine-asparagine-asparagine-glutamine-tryptophan-valine-asparagine-valine-lysine) with the activity of resisting oxidation and inhibiting pancreatic lipase is verified. According to the method, sea cucumber processing byproducts are fully utilized, the resource utilization rate is increased, a scientific basis is provided for high-value utilization of sea cucumber intestines, and meanwhile, a potential material basis is provided for developing natural antioxidants and peptides with lipid-lowering functions.

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 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 present invention discloses a method for dual-mode detection of glufosinate residues in coffee by colorimetry and chemiluminescence, belonging to the technical field of chemical analysis and detection. In this method, the Schiff base formed by 4-aminoantipyrine and glutaraldehyde is used as a complexing agent for Cu 2+ . Then, microwave digestion is used to prepare copper-doped carbon dots Cu-CDs nanozyme. The Cu-CDs nanozyme has excellent peroxidase-like activity, oxidizes colorless 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) into blue-green oxidized ABTS, and is used as a catalyst for chemiluminescence, which can increase the chemiluminescence intensity of the reaction between N-(4-aminobutyl)-N-ethylisoluminol and H2O2 by nearly 100 times. Based on the inhibitory effect of glufosinate on the POD-like activity of Cu-CDs, a sensitive and rapid dual-channel GM detection technology by colorimetry and chemiluminescence has been developed. The method of the present invention has potential application value in coffee safety monitoring.

The invention relates to the technical field of chemical analysis and detection, and aims to provide a high-sensitivity and strong-specificity ferric ammonium citrate detection method aiming at the defect of determining the content of ferric ammonium citrate in a high-salt system so as to improve the detection precision of the content of ferric ammonium citrate in table salt. The K-g-C3N4 (at) PDA nano-enzyme is prepared by adopting a two-step sylvite-assisted thermal copolymerization strategy, the nano-enzyme has peroxidase-like activity and can catalytically oxidize a substrate ABTS and H2O2 to generate a blue-green oxidation product (ox-ABTS) and generate maximum absorption at the wavelength of 416 nm under an acidic condition, ammonium ferric citrate can enhance the peroxidase-like activity of the K-g-C3N4 (at) PDA nano-enzyme, and the K-g-C3N4 (at) PDA nano-enzyme can be used for preparing the nano-enzyme. The concentration of the ferric ammonium citrate in the sample can be measured according to the linear relationship between the concentration of the ferric ammonium citrate and the increase of the absorbance of the ox-ABTS, so that the green color of the ox-ABTS is deepened, and the concentration of the ferric ammonium citrate in the sample can be measured according to the linear relationship. The K-g-C3N4-coated PDA nano enzyme is good in stability and high in salt tolerance, and various ions in the table salt have almost no influence on the detection result, so that the K-g-C3N4-coated PDA nano enzyme has good selection specificity and wider applicability.

The present invention relates to the technical field of bioactive peptides, and particularly relates to an antioxidant peptide based on mussel foot thread, a preparation method, a preparation and its application. The antioxidant peptide is designed and synthesized with reference to the structural characteristics of mussel foot thread proteins mfp-3, mfp-5 and mfp-6, and contains four sequences, namely MFP3-AP1, MFP5-AP2, MFP6-AP3 and MFP-Hybrid. Tyrosine in the peptide is modified to DOPA by enzymatic means, and its stability and activity are enhanced through modifications such as disulfide bond formation, metal ion coordination and PEGylation. The antioxidant peptide has strong DPPH radical scavenging activity, ABTS radical scavenging activity, hydroxyl radical scavenging activity and ferric ion reducing ability, has a protective effect at the cellular level, and can be prepared into liquid preparations, freeze-dried preparations or microcapsule preparations, and is expected to be applied in the fields of antioxidant health products, cosmetics and drugs.

The invention discloses a laccase mutant LacF-25 as well as an expression strain and application thereof. According to the present invention, Trametes hirsuta AH28-2 laccase is adopted as a starting enzyme, and molecular docking is performed to analyze the position structure so as to obtain the mutant gene; after induced expression of engineering bacteria containing the mutant gene, the laccase mutant enzyme LacF-25 with improved toxin oxidative conversion capability is obtained. Under the conditions that the pH is 7 and the temperature is 50 DEG C, the oxidative conversion capacity of the mutant LacF-25 on AFB1 is improved to 1.14 times that of a starting enzyme. When ABTS is used as a substrate, the mutant enzyme LacF-25 is stably increased to 5-9 times that of a starting enzyme under the condition of 35-50 DEG C, and the mutant enzyme has potential application value in oxidative conversion of aflatoxin.

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 present invention belongs to the technical field of plant extracellular vesicles, and specifically relates to an extracellular vesicle of the Polygonatum plant and a preparation method thereof. By performing sucrose density gradient centrifugation, the activity of extracellular vesicles of Polygonatum is greatly improved. In addition, due to the simple operation and strong reproducibility of this method, the extraction rate of extracellular vesicles of Polygonatum is greatly increased. The in vitro antioxidant activity assay shows that, compared with the traditional ultracentrifugation method, the extracellular vesicles of Polygonatum obtained by the preparation method provided by the present invention have 2.01 times and 4.55 times higher antioxidant capacities against DPPH and ABTS respectively, and are more suitable for large-scale extraction of highly active extracellular vesicles of Polygonatum.

The invention relates to a method for constructing a spectrum-effect relationship of dried orange peel from different producing areas based on electrochemical fingerprints in combination with antioxidant activity. The method comprises the following steps: establishing electrochemical fingerprints of dried orange peel from different producing areas under the conditions that the temperature is 35 DEG C, the concentration of sulfuric acid is 1mol / L, the concentration of ceric ammonium sulfate is 0.005 mol / L, the concentration of malonic acid is 0.45 mol / L and the concentration of sodium bromate is 0.3 mol / L; an ABTS free radical scavenging rate method with high sensitivity and stability is selected for antioxidant activity evaluation. Meanwhile, a rapid and accurate spectrum-activity relationship method is established by analyzing the spectrum-activity relationship between the electrochemical fingerprints of the dried orange peel from different producing areas and the semi-inhibitory concentration of the ABTS free radical scavenging rate in combination with Pearson correlation. The method has certain scientific value and wide application value.

The present invention discloses the application of iron-tetracycline nanozymes in the preparation of drugs for treating bacterial meningitis, and belongs to the field of medical technology. The present invention provides a new theoretical strategy for the treatment of bacterial meningitis by integrating the reactive oxygen species scavenging ability of iron-based nanozymes and the broad-spectrum antibacterial effect of tetracycline. Experimental results show that the scavenging rate of iron-tetracycline nanozymes for DPPH and ABTS free radicals is as high as 80%, and hydroxyl free radicals can be effectively degraded. ELISA results show that iron-tetracycline nanozymes can significantly inhibit the secretion of pro-inflammatory factors by BV2 cells, confirming its potential to alleviate neuroinflammation by regulating ROS levels. In addition, the inhibition rate of iron-tetracycline nanozymes on Streptococcus pneumoniae is concentration-dependent, and has excellent biocompatibility, providing new raw materials and treatment methods for the treatment of bacterial meningitis caused by Streptococcus pneumoniae.

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 discloses a vanillic acid derivative containing a thiosemicarbazide structure and application of the vanillic acid derivative. The compound has relatively good oxidation resistance and alpha-glucosidase resistance activity; wherein the IC50 values of the compound 2-(4-(benzyloxy)-3-methoxybenzoyl)-N-isopropylhydrazine-1-methylsulfuryl on DPPH (1, 1-diphenyl-2-picrylhydrazyl) scavenging activity, ABTS (2, 2 '-azinobenzoyl) scavenging activity and alpha-glucosidase inhibitory activity are respectively 5.33 mu g / mL, 5.84 mu g / mL and 34.99 mu g / mL, the effect is the best, and the IC50 values are superior to those of control medicaments such as vanillic acid, vitamin C, vitamin E and acarbose. The vanillic acid derivative containing the thiosemicarbazide structure has a general formula shown in the specification,