465 results about "Keto acid" patented technology

alpha-keto acids and certain precursors and derivatives thereof, particularly those selected from the group which consists of glyoxylic acid, 2-oxo-propanoic acid, 2-oxo-butanoic acid, 3-methyl-2-oxo butanoic acid, 3-methyl-2-oxo pentanoic acid, 4-methyl-2-oxo pentanoic acid, 3-hydroxy-2-oxo-propanoic acid, oxalacetic acid, 2-oxo-glutaric acid, 2-oxo-3-phenyl-propanoic acid, 3-(4-hydroxy-phenyl)-2-oxo-propanoic acid, 2-oxo-1H-indole-3-propanoic acid, 2-oxo-1H-imidazole-4-propanoic acid, 4-methylthio-2-oxo-butanoic acid, 3-mercapto-2-oxo-propanoic acid, 3-hydroxy-2-oxo-butanoic acid, 6-amino-2-oxo-hexanoic acid and 5-guanido-2-oxo-pentanoic acid, and precursors and derivatives thereof that are capable of being formed from or releasing said acids in the use medium, are useful as flavouring ingredients. Such ingredients are useful for preparing flavouring compositions and a wide variety of flavoured foodstuffs to which they impart greater creaminess and bulkiness so that they have heightened effect in the mouth and generally an enhanced mouthfeel. They are also useful for enhancing the sweetness of foods sweetened with natural or artificial sweeteners, and giving it a more natural character.

4-(Indol-3-ylmethyl)-4-hydroxy-2-oxoglutarate, which is useful as an intermediate in the synthesis of monatin, may be synthesized from indole pyruvic acid and pyruvic acid (and/or oxaloacetic acid) by using a novel aldolase derived from the genus Pseudomonas, Erwinia, Flavobacterium, or Xanthomonas.

The invention relates to a composition of matter comprising a soldering flux, wherein the flux consists essentially of a combination of a fluxing agent and a solvent, and wherein the fluxing agent comprises a keto acid such as levulinic acid or acetylbutyric acid. The flux may also comprises an ester acid, or comprises a mixture of the keto acid with the ester acid. The solvent comprises a mixture of a tacky solvent with a non-tacky solvent. The invention also relates to a process comprising soldering at least two surfaces together, each of which comprises a metal area to which solder can adhere by employing the following steps in any order: applying solder to at least one of the metal areas, aligning the metal areas so that they are superimposed over one another, heating at least one of the areas to a temperature that comprises at least the melting temperature of the solder. The last step comprises joining the superimposed areas to one another. The process employs the flux composition operatively associated with the solder, and in one embodiment the invention comprises a mixture of the flux composition with powdered solder. In another embodiment, the process comprises IMS, C4 and C4NP processes and the solder comprises a lead free solder. The invention also comprises a product produced by the foregoing process or processes.

The present invention discloses filter paper sheet gas chromatography-mass spectrum analysis process of organic acid/amino acid metabolic product in urine. The process includes elution of urine collected with filter paper, oximation reaction, extraction, methyl silane derivation, and united detection with chromatographic instrument and mass spectrograph. The process of the present invention is superior in that the filter paper collection of urine favors remote analysis of genetic metabolic diseases; the oximation reaction processing favors alpha-ketonic acid detection for diagnosis of branched chain ketonic acid metabolic disorder; the extraction has high recovery rate of organic acid/amino acid metabolic product, high repeatability, less chromatographic impurity peaks and no pollution to chromatographic capillary column and mass spectrographic ion source; and the united detection is suitable for screening analysis of great amount of samples.

The invention relates to a preparing method of 2-methoxy imino group 2-furan ammonium acetate which comprises the following steps: (1) sodium nitrite reacts with acetate furan to generate furan keto acid by oximation, rearrangement and hydrolysis; (2) the furan keto acid is extracted; (3) condensation reaction is carried out on the furan keto and methoxy ammonium hydrochloride to generate 2-imino group 2-furan acetic acid; (4) the 2-imino group 2-furan acetic acid is extracted; (5) ammonia is introduced for salt formation to generate the 2-methoxy imino group 2-furan ammonium acetate; wherein, solvent adopted in the furan keto extraction of step (2) is butyl acetate. Under the same condition, the dissolution loss of the ethyl acetate in water is four times larger than that of the butyl acetate. With the butyl acetate being adopted as the solvent, the unit consumption is lowered by 50 percent, and the production cost is lowered. Furthermore, 58-60 DEG C of the reaction temperature for oximation is adopted by the invention, the production rate of furoic acid is smaller than 1 percent, and the product yield is improved greatly.

Conversion in vitro of X-Gly to X-alpha-hydroxy-Gly or X—NH₂ (X being a peptide or any other compound having a carbonyl group capable of forming a covalent bond with glycine) is accomplished enzymatically in the presence of keto acids, or salts or esters thereof, to provide a good yield without the necessity of catalase or similar enzymatic reaction enhancers. Peptidylglycine α-amidating monooxygenase (PAM) is a preferred enzyme for catalyzing the conversion. Alternatively, peptidylglycine α-hydroxylating monooxygenase (PHM) is utilized to convert X-Gly to X-alpha-hydroxy-Gly which may be recovered, or optionally may be simultaneously or sequentially converted to an amide by either a Lewis base or action of the enzyme peptidyl α-hydroxyglycine α-amidating lyase (PAL). Both PHM and PAL are functional domains of PAM.

The invention discloses a compound alpha-keto acid dispersible tablet for treating chronic kidney diseases, containing four kinds of keto amino acid calcium, one kind of hydroxyamino acid calcium, five kinds of amino acid and pharmaceutically acceptable adjuvants. The tablet is mainly and clinically used for postponing renal failure process, correcting metabolic disturbance, coordinating with low-protein diet and preventing and treating damages caused by protein metabolism disorder because of chronic renal insufficiency.

The invention discloses escherichia coli gene engineering bacteria for four enzyme co-expression. The engineering bacteria is characterized by introducing an L-amino acid oxidase gene, an alpha-ketonic acid decarboxylase gene, an alcohol dehydrogenase gene, and an enzyme gene capable of reducing NAD(P) to NAD(P)H. The invention further discloses a construction method and application of recombinantescherichia coli. The engineering bacteria is applied to biological synthesis of phenylethyl alcohol compounds, has the characteristics of simple operation, low cost, high product synthetic efficiency, and high optical purity, and has bright industrial prospects.

A synthetic method for aliphatic alpha-calcium picrolonate comprises the following steps: 1. adding carbonyl group reactant in glycolylurea in the presence of catalytic accessory and water and heating, wherein the mol ration of the glycolylurea and the carbonyl group reactant is 1:1.2-1.4; the carbonyl group reactant is aldehyde compound or ketone compound; when aldehyde compound is adopted the catalytic accessory is potassium bicarbonate, and when ketone compound is adopted the catalytic accessory is ethanolamine; 2. cooling to the room temperature, regulating the pH valve to 7 and separating out the intermediate product; 3. filtering and washing the intermediate product; 4. stirring and refluxing the intermediate product and sodium hydroxide solution, wherein the mol ratio of the intermediate product and sodium hydroxide is 1:3-5; 5. regulating the pH value to 4-5, antiregulating the pH value to 7 with the sodium hydroxide solution, and evaporating to remove the moisture; 6. adding absolute methyl alcohol to extract for several times and filtering; 7. distilling to remove the methyl alcohol; and 8. adding de-ionized water and aqueous calcium chloride solution of equivalent amount and separating out alpha-calcium picrolonate. As massive subsidiary products are removed in the method, the calcium content in the prepared product can achieve the standard.

The invention discloses a fluorescent dye having phenazine condensed structure, of which the structural formula is represented as one of the formulas (I) to (IV). The fluorescent dye having phenazinecondensed structure is prepared through steps of: reactions of cyclohexanedione condensation, sodium borohydride reduction, Vilsmeier formylation and the like are carried out to obtain an intermediatecompound; and then reactions with 4-subsituent amino-2-nitrosophenol, benzophenone acid, trans-4-subsituent amino-salicylaldehyde and the like compounds are carried out. Compared with classical fluorescent dyes (e.g. rhodamine, oxazine, squaric acid, anthocyanin dyes), the fluorescent dye in the invention has high photo-stability, is near-infrared in fluorescence emission wavelength of 635-829 nm, and has large Stokes shift capable of reaching 122 nm and high fluorescence quantum yield capable of reaching 0.43. The fluorescent dye can be applied to fields such as luminescent materials, bio-fluorescence probes, multicolor fluorescence imaging, etc.

The present invention has its object to provide a method for producing an L-amino acid comprising reacting a keto acid with an amino acid dehydrogenase and an enzyme having coenzyme regenerating ability to convert to a L-amino acid, wherein a coenzyme is added in two or more portions in the reaction. The method of the present invention enables efficient production of an L-amino acid useful as a synthetic intermediate such as a pharmaceutical intermediate with high optical purity by an enzymatic reductive amination independent of the purity of the keto acid used as a substrate.

Acid generator compounds are provided that are particularly useful as a photoresist composition component. Acid generator compounds of the invention comprise 1) a cyclic sulfonium salt and 2) a covalently linked photoacid-labile group. In one aspect, thioxanthone acid generator compounds are particularly preferred, including acid generator compounds that comprise (i) a thioxanthone moiety; and (ii) one or more covalently linked acid labile-groups.

Methods are disclosed for sterilizing biological materials to reduce the level of one or more biological contaminants or pathogens therein, such as viruses, bacterial (including inter- and intracellular bacteria, such as mycoplasmas, ureaplasmas, nanobacteria, chlamydia, rickettsias), yeasts, molds, fungi, single or multicellular parasites, and/or prions or similar agents responsible. These methods involve the use of alpha-keto acids in methods of sterilizing biological materials with irradiation.