523 results about "Hydroxybutyric acid" patented technology

The present invention provides methods and compositions for preparing 4-substituted 3-hydroxybutyric acid derivatives by halohydrin dehalogenase-catalyzed conversion of 4-halo-3-hydroxybutyric acid derivatives. The present invention further provides methods and compositions for preparing 4-halo-3-hydroxybutyric acid derivatives by ketoreductase-catalyzed conversion of 4-halo-3-ketobutyric acid derivatives The present invention also provides methods and compositions for preparing vicinal cyano, hydroxyl substituted carboxylic acid esters.

This invention relates to a method for the production of D-(-)-3-hydroxybutyric acid, comprising the step of culturing a recombinant strain containing genes phbA, phbB, ptb and buk by fermentation. Preferably, the recombinant strain is a strain of E. coli. The method of the invention is simple, avoiding the technique of degrading polymer to produce D-(-)-3-hydroxybutyric acid. The present method also provides improved efficiency, lowers the complicated requirement for facilities as used in traditional chemical synthesis, simplifies the complicated technique flow, and omits the complicated chiral separation step. Therefore, the present method greatly reduces the costs associated with D-(-)-3-hydroxybutyric acid production. Also, with this invention, the problems such as environmental pollution of chemical synthesis and chiral separation are overcome.

The present invention relates to a method for producing optically active 2-(N-substituted aminomethyl)-3-hydroxybutyric acid esters wherein a 2-(N-substituted aminomethyl)-3-oxobutyric acid ester is treated with an enzyme source capable of stereoselectively reducing said ester to the corresponding optically active 2-(N-substituted aminomethyl)-3-hydroxybutyric acid ester having the (2S,3R) configuration. The present invention provides an efficient method for industrially producing optically active 2-(N-substituted aminomethyl)-3-hydroxybutyric acid esters, in particular such compounds having the (2S,3R) configuration, which are useful as intermediates for the production of medicinal compounds, among others.

A method for producing 2,2,2-trifluoroethanol in which a γ-hydroxybutyric acid salt is reacted with 1,1,1-trifluoro-2-chloroethane to generate 2,2,2-trifluoroethanol is provided. This method leads to increased yields of 2,2,2 -trifluoroethanol, facilitates the separation of salt byproducts and allows the recycling of an aprotic polar solvent.

The present invention concerns a method for producing 2,2,2-trifluoroethanol in which a γ-hydroxybutyric acid salt is reacted with 1,1,1-trifluoro-2-chloroethane in an aprotic polar solvent to generate 2,2,2-trifluoroethanol. This method is characterized in that the γ-hydroxybutyric acid salt used contains no more than 6 wt % of 4,4′-oxybis(butyric acid).

Disposable test strips and a wet chemistry method for measuring each of beta-hydroxybutyrate alone, combined beta-hydroxybutyrate and acetoacetate or total ketone bodies (i.e., beta-hydroxybutyrate, acetoacetate and acetone) in human bodily fluid samples, including but not limited to urine, saliva or sweat are described. The test strips need only be dipped in the sample and can be used by anyone in almost any milieu. Measurement can be made electrochemically, spectrophotometrically, fluorometrically or by comparision to a color standard. Combined acetoacetate and beta-hydroxybutyrate which account for 97-98% of total ketone bodies and may be measured in a cyclic reaction that occurs at pH about 7.0 to about 8.3 with beta-hydroxybutyrate dehydrogenase, (beta-HBD), nicotinamide adenine dinucleotide, a tetrazolium dye precursor and an electron mediator. Using this reaction, false positive results obtained from urine samples taken from patients on sulfhydryl drugs are avoided. beta-HBD from some sources was found to cause false negative results in samples (e.g. urine) containing high chloride content due to chloride inhibition of beta-HBD. Using a simple test for chloride inhibition, it was found that beta-HBD from Alcaligenes is not so inhibited. Using either beta-HBD that is not inhibited by chloride or using 10-20 times the normal concentration of this enzyme eliminates false negatives in samples having substantial chloride content, such as urine, both in the reaction described above and in other reactions disclosed for measuring each of beta-hydroxybutyrate alone, combined beta-hydroxybutyrate and acetoacetate and total ketone bodies, all of which reactions occur in the pH range of about 8.6 to about 9.5.

The invention discloses application of alcohol dehydrogenase with amino acid sequence disclosed as SEQ ID NO:2 in preparing ethyl (R)-4-chloro-3-hydroxy butyrate from ethyl 4-chloroacetoacetate by asymmetric reduction. By using alcohol dehydrogenase with amino acid sequence disclosed as SEQ ID NO:2 as a catalyst, ethyl 4-chloroacetoacetate as a substrate and NADH (nicotinamide adenine dinucleotide) as a cofactor, asymmetric reduction is carried out to prepare the ethyl (R)-4-chloro-3-hydroxy butyrate. The invention applies the alcohol dehydrogenase with amino acid sequence disclosed as SEQ ID NO:2 in preparing ethyl (R)-4-chloro-3-hydroxy butyrate from ethyl 4-chloroacetoacetate by asymmetric reduction for the first time, and has favorable effect. The enzyme activity is up to 5.6 U/mg, the yield of the substrate is up to 94%, and the enantiomeric excess value of the product is 100%. The yield is high, and the production cost is greatly lowered.

The invention discloses an expression system and constructing PHB transgene algae method of rhine chlamydomonas exogenesis gene, which comprises the following parts: promotor, exogenesis-goal gene, screening badge and rhine chlamydomonas acceptor algae strain, wherein the method comprises the following: A, selecting and cultivating acceptor algae strain; B, cloning key enzyme gene by PHB biosynthesizing; C, expressing carrier of PHB biosynthesizing key enzyme rhine chlamydomonas; D, using PHB biosynthesizing key enzyme to lead in rhine chlamydomonas from fungus Bacillus alcaligenes with bead-milling method, gene-gun method or electrization; obtaining bivalence or transgene Chlamydomonas of producing PHB by screen selecting and molecule detecting. The poly-hydroxybutyric acid is compounded by acting in conjunction of PHB compounding key enzyme of phbA, phbB and phbC gene coding, which uses acetylcoenzyme A as substrate by photosynthesis. The method simplifies the operating, which reduces cost.

The present invention relates to a granule of gamma-hydroxybutyric acid or of one of its pharmaceutically acceptable salts, characterized in that it comprises a solid core on which the gamma-hydroxybutyric acid or one of its salts is supported.

The invention discloses a magnetic composite material and an application thereof in regeneration and repair of bone tissues, as well as a method for preparing the magnetic composite material and a product prepared by the magnetic composite material, wherein the magnetic composite material comprises the following components: a) 10-50g of polymer material calculated by 100ml of organic solvent, wherein the polymer material is selected from polylactic acid, polyglycolic acid, lactic acid-glycolic acid copolymer, polycaprolactone, polyamide or poly-hydroxybutyric acid; b) 10g of hydroxyapatite nano-particles calculated by 100ml of the organic solvent; and c) 2.5g of gamma-Fe2O3 nano-particles calculated by 100ml of organic solvent, wherein the organic solvent is selected from tetrahydrofuran (THF), dimethylformamide (DMF), dimethylacetamide (DMAc), chloroform or dioxane.

1. The present invention provides compositions and methods for reversibly inhibiting S-adenosyl-L-homocysteine (SAH) hydrolase. The compounds of the present invention can be used as an anti-hemorrhagic viral infection agent, an immunosuppressant, a homocysteine lowering agent, or an anti-neoplasm agent. The compositions and methods of the present invention can be used for the prevention and treatment of hemorrhagic virus infection, autoimmune diseases, autograft rejection, neoplasm, hyperhomocysteineuria, cardiovascular disease, stroke, Alzheimer's disease, multiple sclerosis or diabetes. The compound of the present invention and/or used in the present invention has the formula (I):

The invention discloses an application of carbonyl reductase with the amino acid sequence as shown in SEQ ID NO:2 to prepare (S)-4-chloro-3-hydroxybutanoic ethyl ester by asymmetric reduction of 4-chloracetyl ethyl acetate. The carbonyl reductase with the amino acid sequence as shown in SEQ ID NO:2 is taken as a catalyst, the ethyl 4-chloracetyl ethyl acetate is taken as a substrate, and NADPH is taken as a cofactor, and the (S)-4-chloro-3-hydroxybutanoic ethyl ester is prepared by the asymmetric reduction. The carbonyl reductase with the amino acid sequence as shown in SEQ ID NO:2 is applied to preparing the (S)-4-chloro-3-hydroxybutanoic ethyl ester by the asymmertric reduction of the 4-chloroacetyl ethyl acetate for the first time, which produces good effect; the yield of the substrate is up to 95%, and the enantiomer excess value of the product is 100%, the yield is high, and the production cost is greatly reduced.

The invention discloses resource-renewable and biodegradable conductive fiber and a preparation method thereof. The fiber consists of the following raw materials in parts by weight: 30-70 parts of polylactic acid (PLA), 30-70 parts of poly(3-hydroxybutyric acid-co-3-hydroxyvalerate (PHBV) and 0.05-8 parts of conductive filler. The preparation method of the conductive fiber comprises the following steps of: (1) proportionally pre-mixing PHBV (if PLA is not less than 50 parts) or PLA (if PLA is less than 50 parts) and the conductive filler, and performing melt blending and granulation to obtain the conductive master batch of the PHBV or PLA; (2) proportionally pre-mixing the PLA or PHBV and the conductive master batch of the PHBV or PLA, and performing melt blending and granulation to obtain composite conductive mater batches; and (3) spinning and drafting the composite conductive master batches one by one to obtain the conductive fiber. The conductive fiber disclosed by the invention can be used as the material for electrodes, static resistance, low-temperature heating, electromagnetic shielding, thermal sensitivity, gas sensitivity and the like.

The invention provides a halogenohydrin dehalogenation enzyme originating from Agromyces sp., an encoding gene and a vector, and provides application of the halogenohydrin dehalogenation enzyme, the encoding gene and the vector in the process of preparing epoxy chloropropane and (R)-4- cyano-cn-3- hydroxybutyric acid ethyl ester. The halogenohydrin dehalogenation enzyme amino acid sequence is shown in SEQ ID NO.2, and the encoding gene sequence is shown in SEQ ID NO.1. The halogenohydrin dehalogenation enzyme, the encoding gene, the vector and the application have the advantages that the halogenohydrin dehalogenation enzyme originating from Agromyces sp. CCTCC NO. M 2012299 and the encoding gene of the halogenohydrin dehalogenation enzyme are provided; and the encoding gene of the halogenohydrin dehalogenation enzyme can be connected and constructed with an expression vector to obtain expression recombinant plasmid pET28b-Deh of the encoding gene, then can be transformed to escherichia coli BL21, obtained and transformed to escherichia coli bacterial strain respectively and correspondingly to obtain recombinant escherichia coli, and the recombinant escherichia coli has the halogenohydrin dehalogenation enzyme and can be utilized for carrying out biotransformation and catalysis for an enzyme source.

The invention relates to a ketoreductase mutant deriving from wild type ketoreductase of lactobacillus kefir. The ketoreductase mutant is capable of converting ethyl-4-chloroacetoacetate to generate (S)-4-chloro-3-hydroxy ethyl butyrate and has one or multiple of mutations in A94S, F147V, L199P and A202V. The ketoreductase mutant provided by the invention has obvious high specific enzyme activity which is improved by 2-20 times in comparison with the wild type ketoreductase; the enzyme can be used for biologically catalyzing to convert the ethyl-4-chloroacetoacetate to generate (S)-4-chloro-3-hydroxy ethyl butyrate; the reaction condition is mild, and the requirement on equipment is low, the production process is free from high temperature or cooling, and the energy consumption is low; since the enzyme catalysis is efficient and unique in selectivity, the method can be used for producing statins key intermediate (S)-4-chloro-3-hydroxy ethyl butyrate without producing byproduct, and the purification is convenient; in addition, the vast majority solvent in the reaction is water, the three-waste emission is low, and the ketoreductase mutant is environmental friendly.