128 results about "Peroxyl radical" patented technology

The invention discloses a hydrogen peroxide measurement method based on N-acetyl-L-cysteine-gold nanoclusters, and relates to a hydrogen peroxide measurement method which takes the gold nanoclusters protected by N-acetyl-L-cysteine as a fluorescent probe. The method is characterized in that the fluorescent light of the gold nanoclusters is quenched by utilizing hydroxyl radicals generated by catalyzing H2O2 through Fe<2+>, so that the characteristic of a fluorescence emission spectrum is changed, and the method can be used for detecting H2O2. Delta F650 and the concentration of H2O2 have a linear relation within the range of 0.044-6.66 micromole/ L, and the limit of detection is 27 nmol/ L. The method is high in sensitivity and good in reproducibility, and can be used for measuring H2O2 in food, industry, environment and a living system.

The invention discloses a catalase fluorescence determination method based on a gold nano-cluster probe and relates to a catalase fluorescence determination method in which a gold nano-cluster protected by N-acetyl-L-cysteine serves as a fluorescence probe. The catalase fluorescence determination method is characterized in that H2O2 is catalyzed by Fe<2+> to generate hydroxyl radicals, so that the fluorescence of the gold nano-cluster is quenched; H2O2 can be catalyzed by the catalase and is decomposed into H2O and O2 to restrain quenching of the fluorescence of the gold nano-cluster, so that the change of fluorescence emission spectrum characteristics is represented, and the catalase can be detected. A linear relation is formed between a fluorescence intensity change value delta F650 and the concentration of catalase within a range of 0.01-0.3U/mL, and the detection limit is 0.002U/mL. The method is high in sensitivity and high in reproducibility, and can be used for determining the catalase in food, industry, environment and life systems.

The invention relates to a nanometer Cu0/Fe3O4 compound, a method for preparing the same and application of the nanometer Cu0/Fe3O4 compound to treating organic wastewater by means of catalytically activating molecular oxygen. The method for preparing the nanometer Cu0/Fe3O4 compound includes (1), adding Cu(NO3)2 3H2O and Fe (NO3)3 9H2O into ethylene glycol according to a molar ratio of (0.05-20):1, dissolving the Cu(NO3)2 3H2O and the Fe (NO3)3 9H2O in the ethylene glycol and stirring the Cu(NO3)2 3H2O and the Fe (NO3)3 9H2O at the temperature of 25-60 DEG C for 30-120 min to obtain mixed liquid; (2), transferring the mixed liquid obtained at the step (1) into a polytetrafluoroethylene reaction kettle and keeping the mixed liquid in the polytetrafluoroethylene reaction kettle at the temperature of 150-200 DEG C for 12-96 h to obtain black precipitates; (3), separating the black precipitates obtained at the step (2) by the aid of centrifugal separation processes, and cleaning the black precipitates by the aid of deionized water until cleaning liquid is neutral so as to obtain the nanometer Cu0/Fe3O4 compound. The nanometer Cu0/Fe3O4 compound, the method and the application have the advantages that the nanometer Cu0/Fe3O4 compound is used as a catalyst, air or oxygen is used as an oxidizing agent, the oxygen is activated to generate active oxygen such as H2O2 and hydroxyl radicals, organic pollutants in water can be degraded, and the nanometer Cu0/Fe3O4 compound and the method are high in efficiency, wide in pH (potential of hydrogen) application range (pH ranges from 3 to 11) and easy to implement and are environmentally friendly; processes for preparing nanometer Cu0/Fe3O4 compound which is the catalyst are simple, the nanometer Cu0/Fe3O4 compound and the method are low in cost, the nanometer Cu0/Fe3O4 compound is magnetic and can be recycled by the aid of magnets, and the like.

The invention discloses a process for simultaneously preparing an antioxidative peptide and an antifreeze peptide through enzymolysis of collagens. The method comprises the following steps: extractingcollagens by taking salmon skin as a raw material, hydrolyzing the collagens into a short peptide solution by utilizing crude enzymes of extracellaluar protease obtained by fermentation of Vibrio sp.SQS2-3, performing centrifugal ultrafiltration by a 3000 Da ultrafiltration tube 4500*g for 45 minutes so as to obtain the antifreeze peptide with effects of protecting myosin and relieving decreaseof Ca<2+>-ATPase activity in multigelation, performing Sephadex LH-20 gel filtration chromatography to separate lower ultrafiltration components so as to obtain the antioxidative peptide which has effects of scavenging DPPH free radicals and hydroxyl radicals and a certain ability of inhibiting DNA oxidative damage and shows concentration-dependent antioxidant activity in oxygen radical absorptioncapacity detection. The LC-MS technology shows that the antioxidant component contains 19 polypeptides.

The invention discloses an external traditional Chinese medicine composition with the efficacies of scavenging free radical and removing redness and swelling. The external traditional Chinese medicine composition is prepared from the following raw materials in parts by weight: 18-24 parts of agilawood, 8-12 parts of honeysuckle, 8-12 parts of sichuan lovage rhizome, 8-12 parts of wild chrysanthemum flower and 3-8 parts of amber. An experiment proves that the external traditional Chinese medicine composition is safe to skin and free of thrill, has the efficacies of effectively removing DPPH free radical, superoxide anion free radical and hydroxyl free radical, and can also play a long-lasting hydrating role; the external traditional Chinese medicine composition are easily available in raw material and simple and convenient in preparation method and environmentally friendly, is easily accepted by people and has good application and market prospects.

The invention relates to a preparation method of Cyclina sinensis enzymolysis polypeptide. The method includes: subjecting fresh Cyclina sinensis to evisceration and homogenization, taking the homogenate, adding alkaline protease to perform enzymolysis, centrifuging the enzymolysis solution and taking the supernatant, carrying out rotary evaporation and concentration, and freeze drying so as to obtain Cyclina sinensis enzymolysis polypeptide with a molecular weight of 15-25kDa. The Cyclina sinensis enzymolysis polypeptide has good antioxidant activity, has a DPPH free radical clearance rate up to 91.24%, a hydroxyl free radical clearance rate up to 62.83%, chelating power to Fe<2+> of 61.13%, and reducing power of 0.331, and also has certain protective effect on hydroxyl free radical induced damaged pBR322 DNA, and can be widely used in antioxidation active products.

The invention relates to a method for preparing antioxidant active peptide by means of fermenting tilapia skin through bacillus subtilis and belongs to the technical field of food processing. The tilapia skin serves as a raw material, bacillus subtilis serves as a fermentation strain to ferment the tilapia skin after pretreatment and extraction, and the tilapia skin antioxidant active peptide is obtained after centrifugation, ultra-filtration and freeze-drying. The fermentation conditions are that bacillus subtilis serves as the fermentation strain, the addition amount of a seed solution ranges from 1% to 8%, and fermentation is conducted for 20-50 h under the conditions that the temperature ranges from 33 DEG C to 37 DEG C and the pH ranges from 6 to 8. The prepared tilapia skin antioxidant active peptide is remarkable in antioxidant effect, the IC50 values of DPPH free radicals and hydroxyl radicals are 1.01 mg/mL and 1.12 mg/mL respectively, and the tilapia skin is a highly potential bioactive peptide raw material.

The invention discloses lactobacillus fermentum JX306 with an antioxidant function and application thereof, and belongs to the technical field of bioengineering. The lactobacillus fermentum JX306 hasa high DPPH free radical and hydroxyl radical scavenging ability, high reducing power, a high Fe2+ chelating ability, a favorable anti-lipid peroxidation ability, and favorable bile salt tolerance, gastrointestinal fluid resistivity and hydrogen peroxide tolerance; and the glutathione peroxidase activity can be remarkably improved, the malondialdehyde level is reduced, the levels of five antioxidant enzymes such as TR3, Prdx1, Gsr, Gpx1 and a nuclear transcription factor Nrf2 are remarkably improved, and the D-gal induced histopathological lesion can be remarkably relieved. The lactobacillus fermentum JX306 provided by the invention plays a big role on improving the oxidation resistance of food with the lactobacillus fermentum JX306 as a fermenting microbe, and has a wide application prospect.

The invention discloses a method of preparing antioxidant peptides by hydrolyzing skin of tilapias using a compound protease and belongs to the technical field of food processing. The method comprises: pretreating and extracting the skin of tilapias as raw material, performing enzymatic hydrolysis with bromelain and alkaline protease, centrifuging, ultrafiltration and spray-drying to obtain tilapia skin antioxidant peptides; enzymatic hydrolysis conditions are: the bromelain is added first after the skin of tilapias is pretreated and extracted, the addition is 1000-3000 U/g, the temperature is 30-50 DEG C, pH is 3-5, enzymatic hydrolysis time is 1-3 hours, the alkaline protease is added afterwards, the addition is 300-4000 U/g, the temperature is 50-60 DEG C, pH is 7-9, and enzymatic hydrolysis time is 2-3 hours; the antioxidant peptides prepared are significant in antioxidant effect, their DPPH free radicals and hydroxyl radicals have IC50 values, 1.23 mg/mL and 1.68 mg/mL, respectively, and the antioxidant peptides are a bioactive peptide material having great potential.

The invention belongs to the technical field of water treatment, and specifically relates to a method for removing organic matters through cooperation of electrochemistry and hydrogen peroxide. According to the method, a solution containing hydrogen peroxide, transition metal ions and organic matters is used as a reaction solution; at a low current density of less than 5.0 mA/cm<2>, the organic matters and hydroxyl radicals are subjected to an electron transfer reaction to generate organic matter free radicals; polymerization reactions are generated between the organic matter free radicals orbetween the organic matter free radicals and the organic matters to form solid polymers; and the solid polymers are removed through solid-liquid separation so as to remove the organic matters. According to the invention, with the method, the technical problems of high oxidant consumption, high energy consumption and generation of a large amount of iron mud in the method for removing pollutants byusing high current, high hydrogen peroxide concentration or sacrificial iron anode in the prior art are solved; and the method has the advantages of simple and efficient operation, recovery of organicresources and energy, reduction of generation of toxic derivatives, reduction of difficulty in subsequent biological treatment process and the like.

The invention provides laminarin and an extraction and separation method thereof. The method comprises the following steps: extracting a laminarin crude extract having a yield of 3.6 percent, which is superior to that of a traditional water extraction method, by adopting a high-temperature high-pressure water extraction method; performing two-step separation by DEAE-anion exchange chromatography and Sephacryl S-300 gel chromatography to obtain a kelp purified polysaccharide PS-3-1 having a molecular weight of 132 KDa. The prepared kelp purified polysaccharide has free radical scavenging activity, has a scavenging rate for hydroxyl radicals and superoxide anion being over 70 percent, and can be developed into a free radical scavenging drug. Furthermore, the purified polysaccharide has a reproduction inhibiting activity on vascular smooth muscle cells, has a reproduction inhibition rate of over 75 percent, and can be used for preparing a vascular smooth muscle cell reproduction inhibitor medicine.

The invention relates to a cosmetic or pharmaceutical product containing an active polypeptide and a preparation method thereof. According to the cosmetic or pharmaceutical product containing the active polypeptide, the active peptide is screened and identified from the fish skin through two indexes such as the hydroxyl free radical scavenging ability and the melanocyte proliferation inhibition ability, and the active peptide has characteristics of good whitening property and good anti-aging function; and after being prepared into whitening and anti-aging cosmetics or pharmaceutical products, the cosmetic or pharmaceutical product has relatively good application prospects and application values.

A cellular antioxidant activity (CAA) assay for quantifying the antioxidant activity of phytochemicals, food extracts, and dietary supplements has been developed. Dichlorofluorescin is a probe that is trapped within cells and is easily oxidized to fluorescent dichlorofluorescein (DCF). The method measures the ability of compounds to prevent the formation of DCF by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (ABAP)-generated peroxyl radicals in human hepatocarcinoma HepG2 cells. The decrease in cellular fluorescence when compared to the control cells indicates the antioxidant capacity of the compounds. The antioxidant activities of selected phytochemicals and fruit extracts were evaluated using the CAA assay and the results were expressed in μ-mol quercetin equivalents/100 μ-mol phytochemical or μ-mol quercetin equivalents/100 g fresh fruit. Quercetin had the highest CAA value, followed by kaempferol, epigallocatechin gallate (EGCG), myricetin, and luteolin among the pure compounds tested. Among the selected fruits tested, blueberry had the highest CAA value, followed by cranberry>apple=red grape>green grape. The CAA assay is a more biologically relevant method than the popular chemistry antioxidant activity assays because it accounts for aspects of uptake, metabolism, and location of species within cells.

The invention relates to application of blue light activated (S)-blebbistatin molecules to killing of drug-resistant acinetobacter baumannii, and a method for killing the drug-resistant acinetobacterbaumannii through the blue light activated (S)-blebbistatin molecules. (S)-blebbistatin molecules are used for cooperating with blue light, and the (S)-blebbistatin molecules generate strong-oxidativehydroxyl radicals (.OH) under blue light irradiation, and can kill the drug-resistant acinetobacter baumannii. (S)-blebbistatin and a bacterial solution are mixed evenly to be irradiated under the blue light and then smeared or dotted on the surface of a flat plate for a period of time, and then it can be observed that the clinical drug-resistant acinetobacter baumannii is killed. The sterilizingefficiency is improved with increasing of the time, and the inducible drug resistance risk is avoided under the condition without light. The application and the method are not limited by bacterial drug resistance, and provide solid and powerful technical support for treatment of the clinical multiple-drug-resistant acinetobacter baumannii.

The invention discloses a bioactivity detection method and application of recombined humanized neuroglobin. The detection method disclosed by the invention comprises the following steps: 1) preparing the recombined humanized neuroglobin to be detected into a sample solution of the set concentration; 2) detecting the capability of the sample solution in eliminating radicals, and using the superoxide anion clearance rate through rhNgb, the hydrogen oxide clearance amount through rhNgb and/or the hydroxyl radical clearance rate through rhNgb as detection indexes; and 3) computing the detection data and comparing the detection data with the bioactivity standard data of the recombined humanized neuroglobin to obtain the detection result. The invention also provides the application of the neuroglobin Ngb in the preparation of a medicament with a function of eliminating the radicals, which provides the train of thoughts for the development of a new medicament. The detection method disclosed by the invention is stable, has the advantages of reliable detection result, high repeatability of the detection data and the like and can be widely applied to tracking the activity of the rhNgb and biological products containing rhNgb, and the detection result can better reflect the bioactivity of rhNgb proteins.

The invention discloses a preparation method of earthworm extract with skin aging resistance. The method comprises the following steps: (1), soaking fresh earthworms in water until no silt exists, soaking the processed earthworms in saline water, continuing to soak the earthworms in a sterilizing solution, performing fishing out, and performing draining; (2), mashing the earthworms, adding water to prepare a solution, performing stirring reaction, then performing constant-temperature placement for 20-40min, and performing filtration to obtain enzymatic hydrolysate and filter residues; (3), adding water into the filter residues to prepare a solution, adding protease to perform enzymolysis, and performing centrifugal filtration to obtain filtrate; and (4), mixing the enzymatic hydrolysate obtained in the step (1) and the filtrate obtained in the step (2) to obtain an extracting solution, carrying out decoloration and deodorization treatment, and then filtering by using an ultrafiltrationmembrane to obtain an earthworm extract. The method is simple in process, mild in condition and free of pollution; the obtained earthworm extract has the capacity of removing superoxide anion free radicals and hydroxyl free radicals; growth and proliferation of human skin fibroblasts can be effectively promoted; and the earthworm extract can be applied to the fields of health care products and cosmetics and has an important application value.

The present invention provides a Qinghai three-thorn polysaccharide tablet which is prepared from following raw materials and adjunct materials proportioned in parts by weight: raw materials: 10-85 parts of Berberis dasystachya Maxim. polysaccharides, 8-85 parts of Hippophae rhamnoides polysaccharides and 3-25 parts of Nitraria tangutorum Bobr. polysaccharides; adjunct materials: 10-25 parts of microcrystalline cellulose, 10-30 parts of starch, 10-20 parts of sucrose and 1-4 parts of magnesium stearate. Research on the present invention has found that the Berberis dasystachya Maxim. polysaccharides, the Hippophae rhamnoides polysaccharides and the Nitraria tangutorum Bobr. polysaccharides alone have good antioxidant activity in vitro anti-oxidation experiments, but a combined use of the three kinds of polysaccharides can significantly improve the inhibition ability on hydroxy free radicals, superoxide anion free radicals and ABTS free radicals at the same concentration, and has significantly enhanced anti-oxidation activity, indicating that the combined use of the three kinds of polysaccharides plays a synergistic effect.