848 results about "Tryptophan" patented technology

The invention discloses a formate dehydrogenase mutant and application thereof in catalytic synthesis of D-mannitol, and belongs to the technical field of bioengineering. According to the formate dehydrogenase mutant provided by the invention, the 18th-site glutamic acid of wild-type formate dehydrogenase with an amino acid sequence shown as SEQ ID NO.2 is mutated into proline, the 57th-site asparagine is mutated into glutamic acid, the 70th-site histidine is mutated into tryptophan, the 235th-site serine is mutated into threonine, and the 316th-site valine is mutated into threonine, so that the formate dehydrogenase mutant is high in enzyme activity and catalytic activity; the coenzyme circulation efficiency during the production of D-mannitol can be obviously improved, so that the yield of D-mannitol can be effectively improved. When the genetically engineered bacterium co-expressed by the formate dehydrogenase mutant and the mannitol dehydrogenase mutant is used for catalyzing 150 g / L fructose to produce D-mannitol, the yield of D-mannitol within 15 h can reach 140 g / L or above.

The invention discloses a full D-type antibacterial peptide with high enzymolysis stability and broad-spectrum antibacterial activity and application thereof. The antibacterial peptide is obtained by sequentially and repeatedly arranging D-type tryptophan, D-type arginine and D-type lysine for four times and carrying out C-terminal amidation; the amino acid sequence of the gene is (D-Trp)-(D-Arg)-(D-Lys)-(D-Trp)-(D-Arg)-(D-Lys)-(D-Trp)-(D-Arg)-(D-Lys)-(D-Trp)-(D-Arg)-(D-Lys)-(D-Trp)-(D-Arg)-(D-Lys)-NH2, and is marked as DWRK-12. The antibacterial peptide shows broad-spectrum antibacterial activity and excellent stability, can effectively resist clinically separated multidrug resistant strains, and keeps high cell selectivity at the same time. Due to the characteristics, the antibacterial peptide has important application value in the aspect of developing novel antibacterial drugs, especially in the field of treatment of infection of multiple drug-resistant bacteria.

The invention discloses a surface-enhanced tryptophan modified nanofiltration membrane as well as a preparation method and application thereof. Belongs to the field of water treatment membrane preparation. The invention aims to solve the technical problems of non-uniform pore size distribution and surface hydrophobicity of the conventional nanofiltration membrane. The method comprises the following steps: adding tryptophan into a piperazine water-phase solution, and carrying out interfacial polymerization with oil-phase trimesoyl chloride to prepare the tryptophan modified nanofiltration membrane. According to the preparation method, the diffusion rate of the piperazine monomer can be adjusted in the interfacial polymerization process by utilizing a similar surfactant structure of tryptophan, meanwhile, the tryptophan has hydrophilicity and can improve the hydrophilicity of the surface of an active layer, and the prepared modified nanofiltration membrane is reduced in molecular weight cut-off, improved in surface hydrophilicity and good in water resistance. The retention rate of organic micro-pollutants is improved, and meanwhile, good anti-pollution performance is achieved.

The invention discloses a 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant and an application of the 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant. Compared with a wild enzyme amino acid sequence as shown in SEQ ID NO.1, the amino acid sequence of the 3 '-adenosine-5'-phosphoryl sulfate synthetase mutant has one or two mutations in the 101 site, the 207 site and the 560 site; preferably, phenylalanine at the 101 site is mutated into tryptophan; cysteine at the 207th site is mutated into glycine; phenylalanine at the 560th site is mutated into tryptophan. The invention also provides a synthesis method and application of the 3 '-adenosine-5'-phosphoryl sulfuric acid. The APS intermediate product inhibition effect of hPAPSS1 is relieved through a point mutation technology, the substrate affinity of hPAPSS1 to ATP is improved, and a mutant enzyme with a high PAPS conversion rate is obtained; and the bifunctional enzyme hPAPSS1 is synthesized by heterologous expression of PAPS in escherichia coli, so that the acquisition of the enzyme is simplified, and the synthesis efficiency of PAPS is improved.

The invention discloses construction and application of an escherichia coli L-tryptophan biosensor, and belongs to the technical field of bioengineering. The L-tryptophan biosensor provided by the invention comprises a mutated leader peptide fragment tnaC-tnaA, a promoter of the mutated leader peptide fragment tnaC-tnaA, a green fluorescent protein coding gene eGFP and a pTrc99a plasmid skeleton, a recombinant strain containing the L-tryptophan biosensor is cultured, the expression of green fluorescent protein in a culture solution is gradually enhanced along with the increase of the concentration of the L-tryptophan, and the fluorescence value of a unit cell shows better correlation when the concentration of the L-tryptophan is 0-1.5 g / L; therefore, when the biosensor is used for detecting the L-tryptophan in the fermentation liquor, the biosensor has the characteristics of simplicity in operation, sensitive response and high threshold value.

The invention discloses an ultrashort-sequence antibacterial peptide rich in lysine and tryptophan, an antibacterial peptide hydrogel and application of the ultrashort-sequence antibacterial peptide and the antibacterial peptide hydrogel. The preparation method comprises the following steps: combining lysine and tryptophan to obtain polypeptide containing five or six amino acids; then amidation is carried out on the C terminal of the polypeptide, fatty acid chain modification is carried out on the N terminal and side chain amino groups, the ultra-short sequence antibacterial peptide rich in lysine and tryptophan is obtained, and the antibacterial peptide has broad-spectrum antibacterial activity for resisting gram-positive and gram-negative bacteria. An antibacterial peptide micelle self-assembly experiment shows that C12-2KW can be self-assembled into stable hydrogel in a 7.17 mu M PBS (Phosphate Buffer Solution), the hydrogel internally has a compact net-shaped structure, can completely cover the peritoneal injury surface and physically isolate the peritoneal injury surface from surrounding tissues, and has a good effect on treating wound infection caused by MRSA (Methicillin-Resistant Staphylococcus Aureus); meanwhile, the compound has the effect of resisting intestinal wall and abdominal wall adhesion after an operation, is low in toxicity, has a very good application prospect in the aspect of preparing clinical antibacterial drugs, and is expected to become a candidate drug of a novel antibiotic.

An engineered bacterium for improving tryptophan yield, a construction method therefor, and a use thereof. A strain capable of tolerating a high concentration of tryptophan was obtained by screening. Genome sequencing and protein sequence analysis of the strain revealed that some proteins in the strain had undergone point mutations, and these mutants can improve the tryptophan yield. In order to further improve the tryptophan yield, modifications are made to a protein sequence expressed by a fadR gene or a protein sequence expressed by a pepD gene in a starting bacterium. Such modifications enable the obtained engineered bacterium to have a higher tryptophan yield than the starting bacterium. In the case of large-scale production, in a 5 L fermentation tank, the tryptophan yield can reach 62.38±5.80 g / L, and the sugar-to-acid conversion rate can reach 24.1%. Compared with the original bacterium, the tryptophan yield is increased by 1.48 folds, and the sugar-to-acid conversion rate is increased by 1.26 folds. The biological material and the use thereof relate to the technical field of molecular biology and have wide practical application value.

The invention belongs to the technical field of microorganisms, and particularly relates to stenotrophomonas maltophilia yg3 and application thereof. The invention discloses stenotrophomonas maltophilia yg3, and the preservation number of the stenotrophomonas maltophilia yg3 is CGMCC (China General Microbiological Culture Collection Center) No.34131. The stenotrophomonas maltophilia yg3 disclosed by the invention has the capability of efficiently synthesizing indoleacetic acid (IAA), and the IAA yield of 98.10 mg / L can be realized without optimization in an NB culture medium containing 5mM L-tryptophan, which is obviously higher than that of other wild strains. Moreover, the stenotrophomonas maltophilia yg3 has a remarkable growth promoting effect on plants (such as hot peppers), pot experiments show that the stenotrophomonas maltophilia yg3 can remarkably increase the number of effective leaves, the plant height and the biomass of the hot peppers, and the stenotrophomonas maltophilia yg3 can be applied to the field of microorganisms. Particularly, the method has important application value in the fields of microbial plant growth promoters and green synthesis of IAA (indoleacetic acid).

The invention discloses a method for detecting soil active organic carbon based on fluorescence spectrometry, and belongs to the technical field of soil detection. The method comprises the following steps: sequentially drying, sieving and grinding fresh soil to obtain a soil sample, and sequentially performing active organic carbon extraction, purification, decoloration and pH regulation on the soil sample to obtain a soil liquid to be detected. The method comprises the following steps: adding fluorescein into a soil liquid to be detected to form a soil internal standard detection liquid, obtaining a soil fluorescence spectrum through three-dimensional fluorescence spectrum scanning, carrying out background deduction and correction coefficient correction, and calculating the active organic carbon concentration of the soil by using tryptophan, tyrosine and SMP fluorescence concentration standard curves. According to the method, an internal standard method is combined with a fluorescence spectrum technology, and through multi-step sample pretreatment and spectrum correction, the detection accuracy and the anti-interference capability are improved, the active organic carbon concentration of the soil can be rapidly and accurately determined, and an effective means is provided for soil carbon cycle research and quality evaluation.

The invention provides a preparation method of an efficient selective antagonist BQ-788, and relates to the technical field of preparation of antagonists. A solid-liquid combination method is adopted for synthesis, due to the fact that dimethyl dialkanoate on a side chain of tryptophan (DTrp) is difficult, Fmoc-DTrp (CO2Me)-OH is obtained through liquid-phase synthesis, p-methoxybenzyl is selected for protecting carboxyl in the synthesis process, the carboxyl can be removed through trifluoroacetic acid subsequently, and the risk that an indole ring of tryptophan is reduced due to hydrogenation can be successfully avoided. According to the present invention, by using the solid phase synthesis method, the fragment can be rapidly and efficiently obtained, the racemization problem during the condensation process can be effectively avoided, the urea is formed on the solid phase, the operation is simple and convenient, the hydrogen and the diphosgene are not used during the preparation process, the production is safe, the obtained product has characteristics of high yield and high purity, and the preparation steps are less.

The invention discloses an early diagnosis and early screening kit for joint detection of Parkinson's disease and application of the kit, and relates to the technical field of medical treatment. The kit is used for combined detection of three proteins, namely alpha synuclein (alpha-Syn), tyrosine 3-monooxygenase / tryptophan 5-monooxygenase activated protein zeta (YWHAZ) and myosin light chain 6 (Myl6), immunochromatography, chemiluminescence and other methods and a double-antibody sandwich method are adopted, the diagnosis efficiency of the YWHAZ protein is prominent, the AUC reaches 0.96, and the detection sensitivity is high. The AUC of Myl6 is 0.92, the AUC of alpha-Syn is 0.82, the joint detection AUC is up to 0.98, the kit is newly added with a time-resolved fluorescence immunochromatography technology, low-background and high-sensitivity detection is realized through a lanthanide-labeled antibody, the change of related protein expression level can be detected in the early stage of Parkinson's disease, early screening and diagnosis are realized, and the kit has the advantages of high specificity, joint detection up to 95%, high sensitivity, high sensitivity and the like. The joint detection reaches 96%, the operation is simple and convenient, and the sample requirement is low.

Disclosed is a strain of Bifidobacterium longum subsp. longum named dipro-O. The Bifidobacterium longum subsp. longum dipro-O used in the present invention has the ability to overproduce BSH, the ability to reduce cholesterol, and the ability to metabolize tryptophan into indole-3-lactic acid, can effectively reduce body weight, significantly lower insulin resistance levels resulting from high-fat diets, reduce the expression of the inflammatory cytokine TNF-α, significantly lower the levels of total cholesterol (TC) and low-density lipoprotein (LDL) in the blood, and increase the level of high-density lipoprotein (HDL), and can ameliorate disorders of the gut microbiome structure. In addition, the strain can also have an ameliorating effect on other lipid metabolism-related diseases such as hyperlipidemia, thereby providing health interventions for the host's body weight, liver, intestinal health, and blood lipid levels. Moreover, pasteurized dipro-O can also have the effect of regulating lipid metabolism, further extending the range of applications of the strain.

The invention discloses weight-reducing and blood-sugar-reducing meal replacement powder for increasing satiety and a preparation method thereof, and belongs to the technical field of meal replacement powder. Comprising resistant starch, bio-enzyme modified whey protein concentrate, bio-enzyme modified soybean protein isolate, bio-enzyme modified white kidney bean hydrolyzed protein, oat fiber powder, nano emulsion milk powder, mogroside, chitosan, inulin, konjac powder, pumpkin seed powder, a cactus extract, a griffonia simplicifolia seed extract and a Chinese waxgourd peel extract. Through the synergistic effect of multiple components and multiple processes, the obvious effects of satiety, weight loss and blood sugar reduction are achieved. 5-hydroxytryptophan in the griffonia seed extract can regulate satiety center and delay hunger sensation; dietary fibers such as the resistant starch and the inulin absorb water and swell in intestinal tracts to form high-viscosity gel, so that the satiety is further enhanced, and the eating frequency and the eating amount are reduced. A low-calorie and high-protein formula is combined with components such as tartronic acid in the Chinese waxgourd peel extract and the cactus extract, so that fat catabolism is accelerated, and fat synthesis is inhibited.

The invention relates to the field of chemical analysis, and particularly discloses a method for detecting indole and derivatives thereof in serum and excrement. Before liquid chromatography-mass spectrometry detection, a methanol-water mixed solvent is adopted for extraction, and freeze grinding, ultrasonic treatment, standing, centrifugation and other steps are carried out. According to the pretreatment process, the influences of complex matrixes and more interfering substances are eliminated, more tryptophan metabolites are detected at the same time, the adopted pretreatment mode is simple, low in cost and environmentally friendly, and qualitative and quantitative detection of indole and derivatives thereof in complex biological samples can be achieved. The indole derivative has important significance in the fields of enhancing the integrity of the intestinal epithelial barrier, inhibiting neuroinflammation, improving insulin resistance and regulating and controlling the polarization direction of immune cells based on deep research of indole and the indole derivative.

The invention discloses a compound environment-friendly corrosion inhibitor as well as a preparation method and application thereof. The choline ionic liquid comprises choline ionic liquid and amino acid, the choline ionic liquid is choline cations; the amino acid is one or more of cysteine and tryptophan. The compound environment-friendly corrosion inhibitor has high corrosion inhibition efficiency, and the compound structure of the compound environment-friendly corrosion inhibitor further improves the protection performance of the compound environment-friendly corrosion inhibitor through a dual adsorption mechanism of the synergistic effect of physical adsorption and chemical adsorption on the metal surface. According to the compound environment-friendly corrosion inhibitor, a full-green ionic liquid corrosion inhibition system is constructed, the environment-friendly requirement is met, and a metal protection solution can be provided for industrial acid pickling and other strong acid working conditions. Not only is the progress of a corrosion inhibition technology promoted, but also more economic and environment-friendly anti-corrosion application can be provided for actual industrial scenes.

The invention discloses an Escherichia coli endogenous alcohol dehydrogenase EcYjgB mutant and application thereof. The mutant is obtained by performing any one of the following mutations (a) to (c) on Escherichia coli endogenous alcohol dehydrogenase EcYjgB as shown in SEQ ID NO.1: (a) mutating serine at the 200th site into arginine; (b) the serine at the 199th site is mutated into aspartic acid, and the serine at the 200th site is mutated into arginine; and (c) the serine at the 199th site is mutated into aspartic acid, the serine at the 200th site is mutated into arginine, and the asparagine at the 240th site is mutated into tryptophan. The mutant is used for efficiently catalyzing reduction of HMF or furfural to respectively synthesize BHMF and furfuryl alcohol, so that the purposes of improving the production efficiency, reducing the production cost and improving the environmental effect are achieved.

The invention belongs to the technical field of biology, and particularly discloses a tryptophan production strain and application thereof. The L-tryptophan high-yield strain T29 is developed and obtained through methods of combining gene modification with mutagenesis screening and the like. The strain T29 is fermented in a 5L tank, the highest yield of L-tryptophan can reach 60.7 g / L, and the conversion rate reaches 18.6%. Therefore, the strain provided by the invention has important industrial application value for industrial production of L-tryptophan and development of an L-tryptophan production strain with higher fermentation performance.

The invention belongs to the technical field of traditional Chinese medicine detection, and particularly provides a construction method and a quality detection method of a specific chromatogram of a tinospora sinensis merr medicinal preparation, octadecylsilane chemically bonded silica is used as a filler, acetonitrile is used as a mobile phase A, an aqueous solution containing monopotassium phosphate is used as a mobile phase B, and a gradient elution procedure is continuously optimized; according to the method, the column temperature is controlled to be 23-27 DEG C, 11 common characteristic peaks are finally obtained, effective separation of 9 common characteristic peaks is achieved, the obtained characteristic chromatogram is stable in base line, good in characteristic peak shape and short in detection time, and a scientific basis is provided for comprehensively establishing the quality control standard of the tinospora sinensis merr formula granules. And moreover, the peak positions of tryptophan, syringin, isovanillin and magnoflorine can be accurately positioned, the known information of characteristic peaks is increased, and the integrity and characteristics of the tinospora sinensis merr medicinal preparations (such as preparations such as formula granules) are fully reflected.

The invention relates to a biomarker for screening intestinal flora transplantation donors and application of the biomarker. The biomarker comprises intestinal flora and metabolites thereof, the intestinal flora comprises phylum firmicalis, bacteroides and the like, and the metabolites comprise short-chain fatty acid, tryptophan, indole, 5-hydroxytryptamine, lipopolysaccharide and the like. According to the method, the intestinal flora of different crowds is deeply analyzed, the relationship between each related index of the intestinal flora and the intestinal flora transplantation effect is studied, sufficient clinical verification is carried out, a biomarker for screening the intestinal flora transplantation donor is excavated, and a standard for judging whether the intestinal flora transplantation donor is qualified or not is established; and a new method and a new idea are provided for efficiently and accurately screening intestinal flora transplantation donors.

A Bifidobacterium longum subsp. longum dipro-017. The Bifidobacterium longum subsp. longum dipro-017 used has the ability to metabolize tryptophan to produce indole-3-lactic acid, can inhibit the pathogenic bacteria Salmonella Typhimurium, Staphylococcus aureus, and Escherichia coli, and can effectively mitigate weight loss caused by ulcerative colitis, improve a DAI score, improve colon length, mitigate the content of lipopolysaccharide (LPS) in blood, and increase the level of anti-inflammatory cytokine IL-10, as well as mitigate the content of bone metabolism indicators tartrate-resistant acid phosphatase (TRAP) and N-terminal propeptide of type I procollagen (PINP) in blood.

The invention discloses aqueous zinc ion battery electrolyte containing an amino acid additive and application of the aqueous zinc ion battery electrolyte, and belongs to the technical field of aqueous zinc ion batteries. The technical problems of serious zinc dendrite growth, hydrogen evolution and generation of by-products of the aqueous zinc ion battery are solved. According to the technical scheme, the aqueous zinc ion battery electrolyte containing the amino acid additive comprises zinc salt, water and the amino acid additive, wherein the amino acid additive is L-tryptophan. The electrolyte has the beneficial effects that the interface environment between the electrolyte and a zinc negative electrode can be improved by adding the L-tryptophan into the electrolyte, the water-based zinc ion battery assembled by the prepared electrolyte is long in cycle life and high in coulombic efficiency, and growth of zinc dendrites and precipitation of hydrogen are effectively inhibited.

The invention relates to a tryptophan high-yield strain as well as a preparation method and application thereof. The strain comprises overexpression of Vhb protein in an indole synthetic pathway enhanced strain. Heterologous hemoglobin Vhb is introduced into the strain to promote C-H functionalization reaction on the C3 position of indole, and an indole synthesis path is enhanced, so that the yield of tryptophan is increased.

The invention discloses a preparation method of tablets for treating gastroenteritis, which comprises the following steps: (1) preparing a lotus leaf and red date extracting solution to obtain an extracting solution I; preparing an egg shell membrane powder extracting solution to obtain an extracting solution II; combining the extracting solution I and the extracting solution II, performing enzyme deactivation treatment, and performing vacuum concentration to obtain paste, so as to obtain extract; (2) adding kudzuvine root powder, threonine and tryptophan into the extract, and uniformly stirring after charging to obtain an auxiliary material; and (3) preparing paste, adding auxiliary materials, pressing into tablets, and coating with a sugar coating or a film coating to obtain the tablets. The auxiliary material prepared by the method disclosed by the invention has good antibacterial activity, has a good inhibiting effect on escherichia coli and staphylococcus aureus, and can effectively improve the sterilizing and antibacterial effects of tablets after being added into the tablets; meanwhile, the prepared tablet has low friability, so that phenomena of powder falling, fragmentation and the like are not easy to occur during packaging, transportation, processing and the like, and the qualified rate of finished products is high.

The invention discloses an engineered glycosyl transferase and application thereof in efficient preparation of triterpenoid saponin. The engineered glycosyl transferase is obtained by mutating serine at the 15th site of UGT74AC1 enzyme into alanine, mutating histidine at the 47th site into aspartic acid, mutating leucine at the 48th site into valine, mutating alanine at the 180th site into serine, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid The mutant is obtained by mutating serine at the 332 site into proline, phenylalanine at the 367 site into tryptophan and lysine at the 420 site into arginine. According to the invention, the glycosyl transferase with high catalytic activity is obtained by modifying an enzyme engineering technology, and good application of the glycosyl transferase in synthesis of triterpenoid saponin is realized. The glycosyl transferase disclosed by the invention can also be coupled with sucrose synthase, or coupled with N-acetylhexosamine kinase and N-acetylglucosamine-1-uridine phosphate transferase, and acetylglucosamine is used as a glycosyl donor, so that cascade production of triterpenoid saponin with lower cost and higher efficiency is realized.

The invention discloses a multifunctional cyclic peptide, and the structure of the multifunctional cyclic peptide is an end-to-end cyclization structure of tryptophan, leucine, lysine, arginine, tryptophan, leucine, arginine, lysine, leucine, tyrosine, lysine, phenylalanine, glycine and glycine. The multifunctional cyclic peptide has the advantages of the cyclic peptide, can be used as a novel bioactive molecule integrating antibacterial, anti-inflammatory and osteogenesis / tooth promoting functions, can meet various clinical requirements, and has a wide application prospect.

The present invention relates to an isolated peptide comprising the amino acid sequence of Formula (I): (O)n-K-(O)m-Z; wherein K is lysine optionally modified with a self-immolative moiety Z is tryptophan or is absent; O is GHGX1Y (SEQ ID NO: 1); G is glycine, H is histidine, Y is tyrosine; each X1 is independently selected from alanine, glycine, serine, asparagine, histidine (H), arginine (R), aspartic acid, tyrosine, and proline; n is 0 – 5; m is 0 – 5; n+m is 3, 4, 5, 6, 7 or 8, and optionally, wherein not all of the X1 residues are proline (P). Such peptide is a coacervate forming peptide. The present invention also relates to methods of preparing coacervate compositions comprising the isolated peptide, optionally also comprising one or more biomacromolecules (payloads). The present invention further relates to the coacervate compositions per se, and their uses, e.g. in methods of treatment or diagnosis.

The present invention relates to a precise lactation feed for lactating sows, and 100 kg of the feed product comprises the following raw materials by weight: 20 to 28 kg of soybean meal, 2 to 5 kg of fish meal, 2 to 5 kg of MCT microcapsules, 0.2 to 0.4 kg of rumen protected methionine, 0.1 to 0.2 kg of rumen protected tryptophan, 1.5 to 2.5 kg of inulin, 1 to 2 kg of sodium lignin sulfonate, 0.01 to 0.03 kg of a fenugreek seed extract, 1.2 to 1.8 kg of sn-2 palmitate, 0.4 to 0.6 kg of alpha-ketoglutaric acid, 0.08 to 0.12 kg of glycine iron, and the balance of water. The feed is prepared from the following raw materials by weight: 0.15-0.25 kg of zinc methionine, 4-8 kg of wheat bran, 1.2-1.8 kg of a calcium propionate solution, 2-3 kg of lactic acid bacteria fermentation liquor, 0.2-0.4 kg of a rosemary extract and the balance of corn, wherein the total weight of the raw materials is 100 kg. The feed is a precise nutrition regulation feed formula for the sows in the lactation period, and milk yield increase, piglet weaning performance optimization and sow body condition protection are achieved through multi-dimensional nutrition intervention.

The invention discloses a synthesis method of a chiral polyaniline nano material and application of the chiral polyaniline nano material in amino acid chiral crystallization. The preparation method comprises the following steps: ultrasonically dissolving unichiral tartaric acid, an aniline monomer and N-phenyl p-phenylenediamine in water, adding a certain volume of an ammonium persulfate aqueous solution to initiate polymerization, centrifuging after complete reaction to obtain a polyaniline-tartaric acid (PANI-TA) chiral nano material, and carrying out ammonia water dedoping and hydrochloric acid solution re-doping to obtain a polyaniline-hydrochloric acid (PANI-HCl) chiral nano material. And finally, respectively adding the polyaniline-hydrochloric acid chiral nano-material into a supersaturated leucine, alanine or tryptophan aqueous solution to induce chiral crystallization, wherein the result shows that the polyaniline-hydrochloric acid chiral nano-material can induce one configuration of amino acid to crystallize more quickly and the other configuration of amino acid with enantiomeric excess remains in the solution. The chiral polyaniline nano material prepared by the method avoids introduction of other chiral molecules in chiral crystallization, is beneficial to separation of products, has the advantages of simplicity in operation, low cost and the like, and has a wide application prospect in the field of chiral resolution.

The present invention provides an objective non-invasive method for examining renal dysfunction in cats. This method for testing renal dysfunction is a method for testing renal dysfunction in cats, and comprises a step for measuring the level of one or more D-amino acids selected from the group consisting of D-tyrosine, D-methionine, D-tryptophan, D-ornithine, and D-histidine in urine of a subject.

The invention belongs to the field of veterinary drugs, and particularly relates to water-soluble amoxicillin powder which comprises the following components: 50-60 parts of amoxicillin, 5-10 parts of polyvinyl alcohol modified beta-cyclodextrin, 1-3 parts of tryptophan, 20-30 parts of a filler and 0.5-1 part of a flavoring agent. The water-soluble amoxicillin powder disclosed by the invention has an excellent slow-release effect and storage stability.