210 results about "ABTS" patented technology

The invention relates to a method for simulating peroxidase by manganese dioxide nanosheet for detection of reductive biological molecules. The peroxidase simulated by manganese dioxide nanosheet can perform catalytic oxidation on substrates of 3,3',5,5'-tetramethyl benzidine TMB, 2,2-azino-di(3-ethyl-benzothiazoles-6-sulfonic acid) diammonium salt ABTS and o-phenylenediamine OPD, and changes the color from colorless to blue, green and orange respectively, at the same time, the manganese dioxide nanosheet can sensitively and selectively perform an oxidation reduction reaction with reductive biological molecules such as glutathione and ascorbic acid, oxidation product concentration of the substrates such as TMB, ABTS and OPD is changed, and then, the reductive biological molecules such as glutathione and ascorbic acid are subjected to quantitative determination through a colorimetric analysis method. The method has the characteristics of simple operation, high sensitivity, good reappearance and high selectivity; a detection linear scope of glutathione is 1-15 [mu]M, the detection limit is 0.3 [mu]M; the detection linear scope of ascorbic acid is 3-100 [mu]M, the detection limit is 0.8 [mu]M; and the method can be used for detecting various phenolic compounds.

The invention discloses a process method for quickly preparing a soybean antioxidant peptide, belonging to the technical fields of deep processing of agricultural and sideline products and comprehensive utilization of byproducts thereof, and relating to the process method for quickly preparing the soybean antioxidant peptide by using a microwave technology. According to the process method, soybean protein concentrate powder with protein content of 70 percent is used as a raw material, the material passes through a microwave extractor through processes of preparing the soybean protein concentrate powder, pretreating soybean protein concentrate powder emulsion, performing microwave auxiliary enzymatic treatment on the soybean protein concentrate powder emulsion, deactivating enzymatic hydrolysate, centrifuging, performing ultrafiltration treatment and performing vacuum freeze drying treatment by using the microwave auxiliary enzymatic hydrolysis technology; the enzymatic hydrolysis time is shortened to 35-38 minutes; and compared with the conventional enzymatic hydrolysis, the efficiency is increased by 3-4 times, and the ABTS (2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)) free radical clear rate is over 72 percent and is equivalent to that of the conventional enzyme. According to the process method, a new idea is provided for technical research for quickly preparing the soybean antioxidant peptide, and a new approach is provided for development and application of soybean series products of high antioxidant activity.

The invention discloses brefeldin A ester derivatives, and preparation and application thereof. The brefeldin A ester derivative compounds have antioxidation activity and antitumor activity, wherein the brefeldin A ester derivative compound disclosed as Formula (I-1), (I-3), (I-5) or (I-7) has favorable antioxidation effect and can remove DPPH, ABTS and super oxygen free radical (O2<->), and the compound (I-7) has better removal effect on DPPH, ABTS and super oxygen free radical (O2<->) than vitamin E; and the compound disclosed as Formula (I-1), (I-3), (I-5) or (I-7) has favorable inhibition activity for human lung cancer cells A549. Therefore, the result shows that the derivatives have wide application prospects in the drug development system, provide a new and broader idea for synthesizing and screening BFA (brefeldin A) derivative drugs and provide a more efficient way for treating related diseases.

The invention relates to a peony seed meal polypeptide with antioxidant activity as well as a preparation method and application thereof. The method comprises the following steps that neutral proteaseand alkaline protease are subjected to synergistic multi-step enzymolysis, after enzymolysis is conducted for 48 h, centrifugal filtration is conducted, supernate is taken, then the supernate, namelyenzymolysis liquid, is subjected to an antioxidant test, and the enzymolysis liquid is subjected to freeze drying to obtain the peony seed meal polypeptide with the antioxidant activity. The method is simple to operate, treatment conditions are mild, after synergistic multi-step enzymolysis of the neutral protease and the alkaline protease, the purity of a peony seed polypeptide product is high,the molecular weight is even, through TricineSDSPAGE electrophoresis detection, the molecular weight of the peony seed polypeptide product is 5.8-6.2 KDa, and the purity is 75% or above; the antioxidant activity of the peony seed meal polypeptide in the molecular weight range is very outstanding, especially, the capability of the polypeptide of clearing ABTS<+> free radicals is very significant, and when the concentration of the polypeptide is 1 mg/mL, the clearance rate is up to 82%.

The invention relates to a pseudosciaena crocea flesh antioxidative peptide and use thereof, and the pseudosciaena crocea flesh antioxidative peptide is characterized in that: the amino acid sequence is Tyr-Leu-Met-Ser-Arg, and the molecular weight is 651.77Da ((M + H) + 652.45Da) given by ESI (electronic spray ion)-MS (mass spectrum) detection. The preparation method of the antioxidative peptide includes homogenizing, enzymolysis, ultrafiltration and chromatography and other steps. The prepared antioxidative peptide Tyr-Leu-Met-Ser-Arg has good scavenging effect on DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical, hydroxyl radical, ABTS radical and superoxide anion free radical; at the same time, the Tyr-Leu-Met-Ser-Arg also shows good lipid peroxidation inhibition effect. The Tyr-Leu-Met-Ser-Arg has significant antioxidant activity, and can be used as medicines, health food or food additives.

The invention relates to the technical field of biomedicine, in particular to a hydrogen peroxide-responsive liposomal nanoprobe and a preparation method and application thereof. The liposomal nanoprobe comprises a liposome, HRP and ABTS, wherein a hydrophilic cavity of the liposome is loaded with HRP, and a hydrophobic layer of the liposome is loaded with ABTS. The hydrogen peroxide-responsive liposomal nanoprobe prepared by the invention has very good hydrogen peroxide responsiveness, and can realize the detection of nano hydrogen peroxide. Compared with the traditional method for detecting hydrogen peroxide by fluorescence or bioluminescence, the photoacoustic imaging detection can significantly improve the depth of penetration of tissues to achieve the hydrogen peroxide imaging of deep tissues; the photoacoustic imaging of the liposome nanoprobe can monitor the occurrence and development of inflammation in real time, and the liposome nanoprobe can react with hydrogen peroxide in a tumor microenvironment to achieve the photoacoustic imaging of tumors.

The present invention provides a detection method and an application of HBV based on CRISPR-Cas12a and G-quadruplex hemin. Processes are as follows: DNA extracted from serum of HBV patients is used asa template, a RPA reaction system comprising an amplification primer pair, rehydration buffer and ddH2O is added to lyophozyme powder, then MgAc is added, the materials are mixed evenly and the mixture is incubated to obtain a RPA product; PS2.M DNA is dissolved in a Tris-HCL solution and a Hemin solution is added to the solution to obtain a PS2.M/Hemin solution; FnCas12a and HBV crRNA are addedto a Tris-HCl buffer and incubated to prepare a Cas12a/crRNA complex solution; and the RPA product, PS2.M/Hemin solution and Cas12a/crRNA complex solution are incubated, and ABTS and H2O2 are added for treatment, and absorbance is measured. The detection method is fast, low in cost, high in accuracy, high in sensitivity and simple in equipment.

The invention discloses a chalcone derivative with good anti-free radical oxidative damage activity. The structural formula of the chalcone derivative is shown as the following. The preparation method of the chalcone derivative includes: letting syringaldehyde and para-substituted acetophenone react in piperidine and under a high temperature so as to generate corresponding substituted chalcone; reacting purified chalcone with sodium borohydride under a cerous chloride heptahydrate condition to generate a chalcone derivative crude product, and then conducting purification. , Compared with ascorbic acid, the product provided by the invention has low anti-DPPH free radical and anti-ABTS<+> free radical IC50 value, and strong free radical scavenging ability, thus having broad application prospects in preparing drugs for treating neurodegenerative diseases. (formula I).

The invention belongs to the technical field of biological detection, and particularly relates to a novel protein-DNA complex for detecting a carcino-embryonic antigen as well as a synthetic method and application thereof. The novel protein-DNA complex comprises a horseradish peroxidase-marked carcino-embryonic antigen secondary antibody, glucose oxidase and a DNA structure. The novel protein-DNAcomplex structure encapsulated with a great amount of enzyme-labeled secondary antibodies and glucose oxidase is established on the basis of a rolling circle replication technology and is used as enzyme cascade signal amplification probe. A 96-pore plate is used for fixing carcino-embryonic antigen monoclonal antibody molecules, after the to-be-detected carcino-embryonic antigen is added, a sandwiched structure is formed. The encapsulated glucose oxidase is used for catalyzing the glucose to be oxidized to generate H2O2, then the H2O2 is catalyzed by virtue of the horseradish peroxidase to oxidize ABTS, so that the high-sensitivity and high-specificity colorimetry detection of the carcino-embryonic antigen can be realized, and the novel protein-DNA complex has important significance for the early diagnosis and clinical research of cancers.

The invention relates to the technical field of snow chrysanthemum extraction, and discloses an antioxidant active extract of snow chrysanthemum and a preparation method thereof. The antioxidant active extract of the snow chrysanthemum is prepared by the following preparation method: firstly, extracting by using an ethanol water solution after crushing the snow chrysanthemum and then carrying out vacuum concentration to obtain an ethanol extract; adsorbing by using macroporous resin, eluting by using an ethanol water solution, carrying out vacuum common peony and drying to obtain the antioxidant active extract of the snow chrysanthemum after extracting by petroleum ether, trichloromethane and ethyl acetate sequentially. The result of an experiment of the antioxidant active extract of the snow chrysanthemum obtained by the method in the ability of removing and restoring DPPH and ABTS free radicals proves that the antioxidant active extract of the snow chrysanthemum disclosed by the embodiment of the invention has good antioxidant action; the process disclosed by the invention is simple and convenient to operate, safe and reliable in extraction process, and is a technique capable of effectively extracting the antioxidant active extract of the snow chrysanthemum.

The invention discloses a colorimetric method for detecting tobramycin based on double strand displacement and a three-dimensional DNA structure, and belongs to the field of food safety, medical analysis and environmental pollution detection. The method comprises the following steps: firstly, double strands T1/T2 are designed; when tobramycin exists, Bsm DNA polymerase synthesizes double strands which are completely complementary through a strong strand displacement reaction, and Nt.BstNBI incision endonuclease cuts recognition sites on the double strands; the three-way DNA structure capture reporter probes, and regenerates and replaces a large number of S1 strands containing G-quadruplex forming sequences. Thereafter, the G-quadruplex/heme catalyzes ABTS<2->/H2O2 chromogenic reaction, andthe tobramycin content can be determined by using the linear relationship between light absorption value and tobramycin concentration. According to the invention, an aptamer captures tobramycin to trigger double strand displacement reaction which is mediated by the Nt.BstNBI incision endonuclease and the Bsm DNA polymerase so as to generate a large number of reporter probes. Meanwhile, the reporter probes trigger lambda exonuclease-assisted loop amplification, so that multiple amplifications of colorimetric signals are realized, the detection range is widened, and the detection sensitivity isimproved.

The invention discloses a double-circulation cascade signal amplification DNA (deoxyribonucleic acid) combination probe composition on the basis of exonuclease III assistance. The double-circulation cascade signal amplification DNA combination probe composition comprises a triggering DNA probe, a hairpin DNA probe, a mercury ion recognition probe and exonuclease III. The triggering DNA probe contains sequences formed by G-quadruplex; a 3' end and a 5' end of the hairpin DNA probe are complementary to each other to form a stem-shaped zone, and sequences of an annular zone are complementary to the triggering DNA probe. A large quantity of G-quadruplex DNA probes can be generated in two spontaneous circulation procedures after a small quantity of Hg2+ is triggered, and are bound with heme to generate G-quadruplex-heme DNA enzymes, ABTS-H2O2 reaction can be catalyzed, and light green ABTS+ which can be visually observed or can be measured by the aid of spectrophotometry processes can be generated; a method for preparing the double-circulation cascade signal amplification DNA combination probe composition is extremely high in sensitivity and specificity, high in detection speed, easy to implement and suitable to be developed to obtain environmental monitoring field real-time analysis technologies; the double-circulation cascade signal amplification DNA combination probe composition is particularly suitable for environments where diversified heavy metal ions are simultaneously available and is applicable to Hg ion monitoring environments when diversified metal pollutants are available.

The invention relates to ultra-Mn2<+>-resistant bacterial laccase, a recombinant vector, recombinant bacteria, an enzymic preparation, a compound enzyme system and a preparation method and an application thereof and belongs to the biotechnical field. The ultra-Mn2<+>-resistant bacterial laccase is originated from bacterial laccase lac1542 of metagenome, and the gene nucleotide sequence of the laccase is as shown in SEQ ID NO.1. The optimum pH of the bacterial laccase taking ABTS as a primer is 4.0; the optimum reaction temperature is 75 DEG C and the bacterial laccase is highly stable at a high temperature; 100mmol/L Mn2<+> still can activate the enzyme. Bacterial laccase, manganese peroxidase and coprinus cinereus peroxidase form the compound enzyme system which can degrade 71.5% of lignin at a low concentration; the decolourization ratio of the bacterial laccase and coprinus cinereus peroxidase compound enzyme system on methyl orange can reach 54.8%. The bacterial laccase provided by the invention can be used in the field of papermaking, dyeing and weaving and environmental protection as a novel enzyme source and has a wide industrial application prospect.

The invention discloses a preparation method of an egg white protein-catechin free radical graft and belongs to the field of food technology. The method comprises the following steps: diluting by adding 9 times volume of water into egg white until the mass fraction of the protein is 1%, adjusting pH to about 5.0, stirring for 10-20 min, naturally precipitating for 1 h, filtering to remove insoluble proteins, taking 50 mL of an egg white solution into a 100mL triangular flask, adding 0.5-2.0 mL of 5M hydrogen peroxide and 0.0625-0.5 g of ascorbic acid, uniformly stirring and placing at room temperature for 2h, adding 0.025-0.1 g of catechin, reacting at 25 DEG C for 12-48 h, dialyzing the sample at 4 DEG C for 12-60 h, changing water every 6 h to ensure that unreacted free polyphenol is completely dialyzed out, and finally freeze-drying to obtain the sample. According to the egg white protein-catechin free radical graft obtained by the above method, the highest DPPH free radical scavenging rate is 65.29%, the ABTS free radical scavenging rate is 94.17%, and the highest reducing power reaches 0.649 Abs.

The invention discloses an application of 3-phenylcoumarin robustic acid in a medicinal preparation for treating diabetes. Free radical removing experiments in vitro prove that the 3-phenylcoumarin robustic acid has obvious removing effects on DPPH free radicals and ABTS free radicals, and IC50 values are 1mg/ml and 0.5mg/ml respectively; the 3-phenylcoumarin robustic acid and 2,6-di-tert-butyl-4-methylphenol have similar antioxidation capabilities. At the same time, the 3-phenylcoumarin robustic acid has a good inhibition effect on alpha-glucosidase activity.

The invention discloses a device for detecting an antioxidative activity compound in a mixture and an operation method of the device, and belongs to a chromatographic analysis technology and the technical field of detection of active compounds. Components with antioxidative activity in the mixture can be rapidly detected. The device consists of a high performance liquid chromatograph (HPLC) comprising a high-pressure pump, a liquid chromatographic column and an ultraviolet-visible detector, a high-pressure pump, a visible detector, a tee joint for the HPLC, a buffer and a reaction coil. The antioxidative activity components in the mixture are measured by chemical free radical ABTS. Each component in the mixture is subjected to liquid chromatographic separation and reacts with the free radical one by one, the free radical fades to form a negative peak through active ingredients, and the number of the antioxidative activity components and the retention time and the antioxidative activity of each component can be obtained by contrasting a chromatogram with a chromatogram after the reaction with the free radical. The method is rapid, simple, convenient and high in sensitivity.

The invention discloses a wax myrtle leaf total-flavonoid extracting method which takes oxidation activity resistance as an index. The method comprises the steps of mixing ethanol and wax myrtle leaves according to the liquid/material ratio of (10-25)mL: 1g, extracting for 5-11 minutes at the temperature of 60-90 DEG C by adopting a microwave-assisted extraction method, carrying out centrifugation for 5 minutes at the rate of 3,500r/min, and extracting supernatant, thereby obtaining a wax myrtle leaf extract, wherein the extraction time is 7.00 minutes when the extraction temperature is 73.3 DEG C, the equivalent of Trolox in the extract assayed by using a DPPH (2,2-di-phenyl-1-picrylhydrazyl) method and an ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid)-diammonium salt) method respectively is 1,352.10mu mol/g and 1,438.73mu mol/g when the liquid/material ratio is 20mL: 1g, and the content of total flavonoids of the extract is 70.94 mg/g. The invention further provides a method for optimizing a wax myrtle leaf total-flavonoid extracting process by using a response surface methodology, wherein oxidation activity resistance is taken as an index, three variables, namely extraction temperature, extraction time and liquid/material ratio, are set, and optimization is carried out by using Design Expert software according to Box-Behnken design principles. The method has the advantages that the cost is low, the extraction time is short, the extraction efficiency is high, and the source of raw materials is wide.

The invention provides a synthetic method for 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, namely, the synthetic method for ABTS. The method includes the steps as follows: taking N-ethyl aniline as a raw material to react with thiocyanate and generating N-ethyl-N-anilinothiourea; reacting with bromine after separation to prepare N-ethyl-2imidobenzothiazole hydrobromide; then reacting with hydrazine hydrate to prepare the key intermediate 2, 2'-azino-bis (3-ethylbenzothiazoline); using concentrated sulfuric acid for sulfonation; and finally using ammonia water for a neutralization reaction to prepare the target compound ABTS. The method has the advantages of easiness in easy operation, high yield and purity, and the like, and is suitable for industrial production.

The invention relates to ganoderam lucidum karst laccase preparation, which in detail relates to a blue copperas- containing liquid laccase preparation produced with Ganoderma lucidum through inclined-plane culture and two- stage fermentation, the blue copperas concentration is 0.15- 0.40 mol/l. The culture medium of first- stage comprises amylaceum, maize flour, bran flour and water, and the culture condition is 25- 35 Deg. C and for 6- 12 days. The further fermentation culture medium comprises bran flour, peanut shell powder, maize flour and water, and the culture condition is 25- 35 Deg. C and for 3- 7 days. The enzymatic activity of said preparation is 32841.36U/l (taking ABTS as substrate). It can be used in field of textile, paper making, food and beverage after being diluted for 200- 250 times, and used for biological sensor production.

The invention discloses a method for preparing flaxseed gum oligosaccharides by a hydrogen peroxide oxidation degradation technology. The flaxseed gum oligosaccharides (FGOSs) are prepared from commercial flaxseed gum by adopting a high pressure assisted hydrogen peroxide oxidation degradation technology through dynamic dissolving, oxidative degradation, suction filtering, decolorizing, ultrafiltration, dialysis, concentration and freeze-drying. The FGOSs obtained in the invention are a semisolid viscous substance, have a light reddish brown color and special fragrance, can be easily dissolved in water, are insoluble in ethanol and other organic solvents, can easily absorb moisture, are a typical carbohydrate substance, and contain uronic acid; the FGOSs have uniform components, the average molecular weight is 1047 Da, the FGOS have a pyranose ring structure, belong to pyranose, and are composed of the following seven monosaccharides: rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose, and the FGOS have certain anti-oxidation ability, and have a high removal rate on hydroxyl free radicals, DPPH free radicals, ABTS free radicals and superoxide anion free radicals.

The invention discloses a method for coordinative extraction of auricularia heimuer melanin through coordination of cellulases and ultrasonic waves. The preferable condition lies in that the additionquality of enzymes is 12mg, the enzymolysis temperature is 40 DEG C, the enzymolysis pH is 5.0, the enzymolysis time is 120min, the concentration of NaOH is 1.27mol/L, the ratio of materials to liquidis 1 to 40 g/ml, the ultrasonic power is 300W, the ultrasonic time is 52min, and the ultrasonic temperature is 60 DEG C. Under the best condition, the extraction yield of auricularia heimuer melanincan achieve 10.48%. Compared with the extraction yield of melanin of an ultrasonic wave group free from cellulases, arranged for experiment, the extraction yield of melanin is increased by 12.93%. Oxidation resisting results indicate that compared with the melanin extracted without the cellulases, the melanin extracted through coordination of the cellulases and the ultrasonic waves has the advantage that the capacity for clearing ABTS, DPPH and hydroxyl free radicals is higher. The method provides a foundation for establishment of application and development of efficient extraction and products of the auricularia heimuer melanin.

: after smashing the dry product of a lyophyllum decastes fruiting body, soaking in 95% ethanol; after degreasing and drying, carrying out high-speed shearing extraction for 1 to 4 minutes at the ratio of materials to liquid being 1:15-25 and at the rotation speed of 9500 to 14500 rpm; centrifuging an extracting solution to discard precipitate, and collecting liquid supernatant; and after concentrating the liquid supernatant, carrying out grading alcohol precipitation, centrifuging, and carrying out freeze-drying to obtain the lyophyllum decastes polysaccharide extract. The lyophyllum decastespolysaccharide extract has obvious antioxidant activity and certain reducing power, can effectively remove ABTS free radicals and DPPH free radicals, and can be applied to the preparation of novel antioxidants. As lyophyllum decastes is safe and natural and has no toxic side effects, the lyophyllum decastes polysaccharide extract has good application prospect.

The invention discloses a low-molecular-weight blackberry polysaccharide and a preparation method thereof. The weight-average molecular weight of the low-molecular-weight blackberry polysaccharide is180-590 thousand Da; the particle size of the low-molecular-weight blackberry polysaccharide in solutions is 400-1,000 microns, and the dispersion index of the low-molecular-weight blackberry polysaccharide in the solutions is 0.18-0.29; the low-molecular-weight blackberry polysaccharide is prepared from, by weight, 9.8-11.2% of arabinose, 3.1-3.6% of galactose, 2.7-3.3% of glucose, 81.9%-83.5% ofgalacturonic acid and 0.40-0.42% of glucuronic acid; the IC50 value of scavenging activity on ABTS free radicals is 1.47-1.62 mg/mL, and the IC50 value of inhibitory activity on alpha-glucosidase is1.11-1.59 mg/mL. A water extract and alcohol precipitate method is adopted and combined with an ultrasonic degradation method to obtain the low-molecular-weight blackberry polysaccharide, and the low-molecular-weight polysaccharide has excellent oxidation resistance performance and hypoglycemic activity.

The invention discloses a method for screening and purifying bunge pricklyash leaf endophytic bacillus safensis GHF4 and an application thereof, the bacillus safensis is preserved in China Center for Type Culture Collection with a preservation number CCTCC NO: M2014535, and is named as GHF4. The method is characterized by comprising the following steps: taking fresh bunge pricklyash leaf, disinfecting and cleaning, performing plate enrichment culture, performing gradient dilution plate coating, primary screening, secondary screening and the like to realize screening and purifying. its fermentation metabolites has strong antioxidant activity, when the concentration of a broth is 3.75mg/mL, clearance to ABTS free radical by endophytic bacillus safensis can reach 99.48%, and IC50 value is 0.80mg/mL. The endophytic bacillus safensis has good application prospect on production aspect of a natural anti-oxidant.