- Pyridoxamine, a scavenger agent of carbohydrates
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Pyridoxamine has been found to inhibit protein glycation and to avoid the formation of advanced glycation end-products (AGEs). One of the mechanisms by which pyridoxamine can inhibit glycation involves the scavenger of carbonyl groups with glycation capacity. In this work, we conducted a kinetic study of the reactions of pyridoxamine with various carbohydrates under physiological pH and temperature. The reactions involving hexoses were found to give a tricyclic compound (5) in addition to pyridoxal and pyridoxine. Such a tricyclic compound inhibits the Amadori rearrangement and the formation of other carbonyl compounds with glycating properties. The reactions involving pentoses gave compound 7 and pyridoxal - by transamination of the Schiff base. The transamination reaction enhances the inhibitory action of pyridoxamine. The formation rate constants for the Schiff base, k3, were found to be similar to those for the reactions of D-glucose with amino acids, which suggests competition between pyridoxamine and terminal amino residues in proteins for glycating sites in sugars. These constants are dependent on the electrophilic character of the carbonyl carbon in the carbohydrate.
- Adrover, Miquel,Vilanova, Bartolome,Munoz, Francisco,Donoso, Josefa
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- Purification and characterization of pyridoxine 5′-phosphate phosphatase from Sinorhizobium meliloti
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Here we report the purification and biochemical characterization of a pyridoxine 5′-phosphate phosphatase involved in the biosynthesis of pyridoxine in Sinorhizobium meliloti. The phosphatase was localized in the cytoplasm and purified to electrophoretic homogeneity by a combination of EDTA/lysozyme treatment and five chromatography steps. Gel-filtration chromatography with Sephacryl S-200 and SDS/PAGE demonstrated that the protein was a monomer with a molecular size of approximately 29kDa. The protein required divalent metal ions for pyridoxine 5′-phosphate phosphatase activity, and specifically catalyzed the removal of Pi from pyridoxine and pyridoxal 5′-phosphates at physiological pH (about 7.5). It was inactive on pyridoxamine 5′-phosphate and other physiologically important phosphorylated compounds. The enzyme had the same Michaelis constant (K m) of 385 μM for pyridoxine and pyridoxal 5′-phosphates, but its specific constant [maximum velocity (Vmax)/Km] was nearly 2.5 times higher for the former than for the latter.
- Tazoe, Masaaki,Ichikawa, Keiko,Hoshino, Tatsuo
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- Biosynthesis of vitamin B6 in Rhizobium: in vitro synthesis of pyridoxine from 1-deoxy-D-xylulose and 4-hydroxy-L-threonine.
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Pyridoxine (vitamin B6) in Rhizobium is synthesized from 1-deoxy-D-xylulose and 4-hydroxy-L-threonine. To define the pathway enzymatically, we established an enzyme reaction system with a crude enzyme solution of R. meliloti IFO14782. The enzyme reaction system required NAD+, NADP+, and ATP as coenzymes, and differed from the E. coli enzyme reaction system comprising PdxA and PdxJ proteins, which requires only NAD+ for formation of pyridoxine 5'-phosphate from 1-deoxy-D-xylulose 5-phosphate and 4-(phosphohydroxy)-L-threonine.
- Tazoe, Masaaki,Ichikawa, Keiko,Hoshino, Tatsuo
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- Environmentally friendly preparation method for vitamin B6
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The invention relates to an environmentally friendly preparation method for vitamin B6. The method comprises the following steps: carrying out a condensation reaction on a carbonyl compound and 2-cyano-2-cis-butene-1,4-diol which is used as a starting material, protecting hydroxyl groups to obtain 2,2-disubstituted-5-cyano-4,7-dihydro-1,3-dioxepine, carrying out a formylation reaction on the 2,2-disubstituted-5-cyano-4,7-dihydro-1,3-dioxepine, carbon monoxide and hydrogen to prepare 2,2-disubstituted-5-cyano-6-formyl-1,3-dioxetpin, condensing the 2,2-disubstituted-5-cyano-6-formyl-1,3-dioxetpin and 2-aminopropionate or its hydrochloride, and removing the carbonyl compound to prepare the vitamin B6. The method does not use a 4-methyl-5-alkoxyoxazole intermediate which is expensive and generates a large amount of wastewater in the production process, so the method has the advantages of environmentally friendly process, high reaction selectivity, high product purity, high atom economy, and suitableness for industrial production.
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- Preparation method of high content vitamin B6
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The invention relates to a preparation method of a high content vitamin B6. According to the method, 1,5-dihydro-3,3-disubstituent group-8-methyl-9-alkyl carbonyl oxypyrido [3,4-e]-1,3-dioxane is prepared by the Diels-Alder addition reaction, aromatization reaction and esterification reaction of 4-methyl-5-alkoxyl-oxazole and 2,2-disubstituent group-4,7-dihydro-1,3-dioxepine in the presence of ananhydride through the "one-pot method", and then vitamin B6 is prepared by deprotection. According to the method, the stability of the raw materials of 4-methyl-5-alkoxyl-oxazole and 2,2-disubstituentgroup-4,7-dihydro-1,3-dioxepine are ensured, the reaction is thorough, and the selectivity is high, so that the method provides guarantees for the preparation of high content medicinal vitamin B6.
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Paragraph 0047-0048
(2019/07/16)
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- Method for preparing vitamin B6 by reduction method
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The invention discloses a method for preparing a vitamin B6 in a reduction manner. The method comprises the following steps of (a), dissolving 2-methyl-3-hydroxypyridine-4,5-diformate in a solvent, adding a weak reducer and an organic acid, raising a temperature to 40 to 90 DEG C, carrying out a reflux reaction for 2h to 5h, and cooling the temperature, so as to obtain a solution system; (b), adding hydrochloric acid into the solution system to regulate to be acidic, then adding sodium hydroxide to regulate to be alkaline, filtering, extracting filtrate, and introducing a HCl gas into an extract phase, so as to obtain a saturated solution; (c), standing the saturated solution at room temperature for devitrification, filtering, washing, oven-drying, recrystallizing and filtering, wherein inthe step (a), the weak reducer is sodium borohydride or potassium borohydride; the organic acid is one of formic acid, acetic acid, oxalic acid, trifluoroacetic acid, propionic acid, benzoic acid andtartaric acid. By the combination of the low-cost weak reducer sodium borohydride or potassium borohydride and the organic acid which are adopted by the method to prepare the vitamin B6, the ester isjointly reduced, and a reaction condition is mild.
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Paragraph 0020; 0023; 0032; 0033
(2018/09/08)
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- Effect of structure of nucleophile and substrate on the quaternization of heterocyclic amines
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The influence of the nature of the quaternizing agent and substrate on the quaternization of heterocyclic amines, derivatives of pyridine, ss-picoline, nicotinamide, pyridoxine, was studied. The synthesized compounds were characterized by IR spectroscopy and elemental analysis. The conclusions were made about the effect of the structure of nucleophile and substrate on the process of quaternization reaction. Pleiades Publishing, Ltd., 2010.
- Zhuravlev,Verolainen,Voronchikhina
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experimental part
p. 1025 - 1028
(2011/01/11)
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- STABLE VITAMIN B6 DERIVATIVE
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A compound represented by the following general formula (I) or a salt thereof: wherein R1 represents a glycosyl group, a phosphate group, or a cyclic phosphate group bound to R2; R2 represents -CH2OH, -CHO, -CH2NH2, -CH2-amino acid residue, or -CH2-OPO2H; and R3 represents hydrogen atom, or -PO3H2, and a composition for cosmetics, medicaments, foodstuffs, and/or feeds containing the aforementioned compound or a salt thereof.
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Page/Page column 16
(2008/06/13)
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- Silane reduction of 5-hydroxy-6-methyl-pyridine-3,4-dicarboxylic acid diethyl ester: Synthesis of vitamin B6
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Alternative methods for the synthesis of pyridoxine have been investigated. The key intermediate, 5-hydroxy-6-methyl-pyridine-3,4-dicarboxylic acid diethyl ester (5), was reduced with either a silane monomer (MeSiH(OEt)2) or a polysiloxane (polymethylhydrosiloxane, PMHS) to afford crude pyridoxine. An isolation technique utilizing a commercially available resin was devised, affording the desired product, vitamin B6, in an overall yield of 38-54% and a purity of 76%.
- Dumond, Yves Rene,Gum, Andrew G.
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p. 873 - 881
(2007/10/03)
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- Novel compositions for the delivery of negatively charged molecules
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This invention features permeability enhancer molecules, and methods, to increase membrane permeability of various molecules, such as nucleic acids, polynucleotides, oligonucleotides, enzymatic nucleic acid molecules, antisense nucleic acid molecules, 2-5A antisense chimeras, triplex forming oligonucleotides, decoy RNAs, dsRNAs, siRNAs, aptamers, or antisense nucleic acids containing nucleic acid cleaving chemical groups, peptides, polypeptides, proteins, carbohydrates, steroids, metals and small molecules, thereby facilitating cellular uptake of such molecules.
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- Production of pyridoxal phosphate by a mutant strain of Schizosaccharomyces pombe.
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Conditions for extracellular production of vitamin B6 compounds (B6), especially pyridoxal 5'-phosphate (PLP) by Schizosaccharomyces pombe leul strain were examined. The productivity was dependent on concentration of L-leucine in the culture medium: 30 mg/l gave the highest concentrations of total B6 and PLP. The viable cells harvested at different growth phases showed different productivity: middle and late exponential phase cells showed the highest productivity of total B6 and PLP, respectively. D-Glucose (1%, w/v) among other sugars gave the best productivity. Supplementation of air and ammonium sulfate significantly increased extracellular production of PLP. Superoxide anion producers, menadione and plumbagin, and H202 increased the productivity of PLP. Cycloheximide inhibited the increase of PLP by the oxidative stress and, in contrast, increased pyridoxine.
- Chumnantana,Hirose,Baba,Yagi
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p. 1789 - 1795
(2007/10/03)
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- Compositions and methods for prevention and treatment of chronic diseases and disorders including the complications of diabetes mellitus
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This invention relates to nutrient and therapeutic compositions for treatment and prevention of symptoms and disease conditions associated with microangiopathy and macroangiopathy and to methods using the compositions. In particular, the invention relates to compositions useful in the treatment of diabetic retinopathy and nephropathy, to compositions useful in the treatment of other retinal disorders including macular degeneration and cataracts, to compositions useful in wound healing, to compositions useful for treatment and prevention of neuropathy, to compositions useful for treatment and prevention of cardiovascular disease and to compositions useful for the treatment and prevention of dental and periodontal disorders.
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- Compounds for cardiovascular treatment comprising multi-vitamin and anti-platelet aggregating agents and methods for making and using the same
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Compounds comprising multi-vitamins, zinc and an anti-platelet aggregating agent for the treatment of atherosclerotic cardiovascular disease (ASCVD) are disclosed. The compounds are provided in dosage form, and preferably include selected amounts of ascorbic acid, folic acid, vitamin E, vitamin B6 and vitamin B12. The anti-platelet aggregating agent preferably comprises aspirin. A protective coating is preferably provided between the aspirin and the other vitamin and mineral constituents. The dosages are effective in the treatment of ASCVD, and possess extended shelf lives.
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- Lipase-catalyzed acylation and deacylation reactions of pyridoxine, a member of vitamin-B6 group
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A series of acyloxy derivatives of pyridoxine (1) have been prepared by transesterification reactions of 1 and ethyl carboxylates, catalyzed by several lipases. Moreover, acetylated derivatives of 1 were selectively deacetylated by enzymatic catalysis in organic media.
- Baldessari, Alicia,Mangone, Constanza P.,Gros, Eduardo G.
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p. 2407 - 2413
(2007/10/03)
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- Facile Synthesis of 13C-2-Butenedinitrile and Regiospecifically Labeled 13C,15N-Pyridoxines
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Syntheses of -2-butenedinitrile in a one-pot process and pyridoxines regiospecifically multi-labeled with carbon-13 and nitrogen-15 are described.
- Hoshino, Jun-ichi,Yamamoto, Yukio,Hasegawa, Takeshi,Takahashi, Sho,Sawada, Seiji
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p. 1939 - 1941
(2007/10/02)
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- Method and composition for supplementing vitamin B6 where the PN-PLP pathway is disturbed
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Treatment or prophylaxis of depressed or inadequate intracellular pyridoxal phosphate levels in a human or animal patient resulting from a condition, wherein the pyridoxihe (PN)--pyridoxal phosphate (PLP) pathway is disturbed or insufficient, either by chemical factors as occur in physiological shock myocardial, infarction, release of polyamines or toxins by cell death or microbes, vitamin B6 antagonistic drugs; or by enzymatic insufficiencies inherent in the cells of a patient caused by genetic lack of oxidase or genetic oxidase polymorphism; cellular immaturity of premature infants; in conditions involving anemia, destruction of erythrocytes (e.g. malaria, biliary fever). The deficiencies are counteracted by the administration of pyridoxal or a precursor of pyridoxal which in vivo, once it has entered the bloodstream, is rapidly converted into pyridoxal without the intervention of oxidase or oxygen, optionally and preferably without the intervention of kinase.
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- Pharmaceutical compositions capable of increasing cerebral serotonin concentration
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A pharmaceutical composition suitable for increasing cerebral serotonin concentration, comprising a serotonin precursor selected from the group consisting of 5-hydroxytryptophan and derivatives of 5-hydroxytryptophan having the formula: STR1 wherein R represent hydrogen; a C1 -C12 alkyl group; or a C5 -C16 alicyclic, monocyclic aromatic hydrocarbyl, or polycyclic aromatic hydrocarbyl group; and a nitrogenous heterocyclic compound selected from the group consisting of inosine, theophylline, theobromine, allopurinol, pyridoxine, hypoxanthine, folic acid, adenine, nicotinamide, caffeine, and orotic acid.
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- Fluorodehydroxylation of serine
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Organic compounds containing one or more alcoholic hydroxyl groups are transformed into fluorine compounds by reacting them with sulfur tetrafluoride in liquid hydrogen fluoride solution, at temperatures between around -80° C. and +20° C. The method can be descriptively termed "fluorodehydroxylation", because it represents the reaction:
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