TRACER EXPERIMENTS ON THE MECHANISM OF URIC ACID DECOMPOSITION AND ACETIC ACID SYNTHESIS BY CLOSTRIDIUM ACIDI-URICI

: Xanthine oxidase (EC 1.17.3.2) (XO) is one of the main enzymatic sources that create reactive oxygen species (ROS) in the living system. It is a dehydrogenase enzyme that performs electron transfer to nicotinamide adenine dinucleotide (NAD+ ), while oxidizing hypoxanthin, which is an intermediate compound in purine catabolism, first to xanthine and then to uric acid. XO turns into an oxidant enzyme that oxidizes thiol groups under certain stress conditions in the tissue. The last metabolic step, in which hypoxanthin turns into uric acid, is catalyzed by XO. Uric acid, considered a waste product, can cause kidney stones and gouty-type arthritis as it is crystallized, when present in high concentrations. Thus, XO inhibitors are one of the drug classes used against gout, a purine metabolism disease that causes urate crystal storage in the joint and its surroundings caused by hyperuricemia. Urate-lowering therapy include XO inhibitors that reduce uric acid production as well as uricosuric drugs that increase urea excretion. Current drugs that obstruct uric acid synthesis through XO inhibition are allopurinol, febuxostat, and uricase. However, since the side effects, safety and tolerability problems of some current gout medications still exist; intensive research is ongoing to look for new, effective, and safer XO inhibitors of natural or synthetic origins for the treatment of the disease. In the present review, we aimed to assess in detail XO inhibitory capacities of pure natural compounds along with the extracts from plants and other natural sources via screening Pubmed, Web of Science (WoS), Scopus, and Google Academic. The data pointed out to the fact that natural products, particularly phenolics such as flavonoids (quercetin, apigenin, and scutellarein), tannins (agrimoniin and ellagitannin), chalcones (melanoxethin), triterpenes (ginsenoside Rd and ursolic acid), stilbenes (resveratrol and piceatannol), alkaloids (berberin and palmatin) have a great potential for new XO inhibitors capable of use against gout disease. In addition, not only plants but other biological sources such as microfungi, macrofungi, lichens, insects (silk worms, ants, etc) seem to be the promising sources of novel XO inhibitors.

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Effect of Riboflavin Deficiency on the Metabolism of Oxypurines in Chicks

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y71-150 ◽

1971 ◽

Vol 49 (12) ◽

pp. 1059-1062 ◽

Cited By ~ 1

Author(s):

S. T. Chou

Keyword(s):

Uric Acid ◽

Acid Synthesis ◽

Xanthine Dehydrogenase ◽

Broiler Chicks ◽

Uric Acid Concentration ◽

Riboflavin Deficiency ◽

Deficient Diet ◽

High Incidence ◽

Liver And Kidney ◽

Riboflavin Deficient

Day-old broiler chicks of both sexes were used in three experiments to determine the effect of riboflavin deficiency on oxypurine metabolism catalyzed by xanthine dehydrogenase, a riboflavin-containing enzyme. Chicks fed a riboflavin-deficient diet (1.38 mg/kg) for 3 weeks exhibited depressed growth and a high incidence of curled-toe paralysis (higher than 80%) as compared to control chicks (15.1 mg riboflavin per kilogram diet; no incidence of curled-toe paralysis). In addition, the precursors of uric acid, hypoxanthine and/or xanthine, accumulated in the liver and kidney of deficient chicks showing curled-toe paralysis. These observations show that dietary riboflavin being incorporated into xanthine dehydrogenase is essential for oxypurine metabolism. Moreover in the chick, the liver and the kidney may be important sites of uric acid synthesis. The low uric acid concentration in the plasma of the deficient chicks appeared to be indicative of a disturbance in uric acid synthesis in the liver and kidney.

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Acetic Acid Synthesis by Catalytic Carbonylation of Methanol

ChemInform ◽

10.1002/chin.200745224 ◽

2007 ◽

Vol 38 (45) ◽

Author(s):

Anthony Haynes

Keyword(s):

Acetic Acid ◽

Acid Synthesis ◽

Catalytic Carbonylation

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Metabolism of the Black Snake Embryo

Journal of Experimental Biology ◽

10.1242/jeb.30.4.492 ◽

1953 ◽

Vol 30 (4) ◽

pp. 492-501 ◽

Cited By ~ 1

Author(s):

HUGH CLARK

Keyword(s):

Energy Source ◽

Uric Acid ◽

Acid Synthesis ◽

K Value ◽

Embryonic Tissues ◽

Hatching Time ◽

Urea Content ◽

Foetal Liver ◽

Liver And Kidney ◽

Post Deposition

1. Post-deposition growth of the black snake embryo is characterized by k values as follows: days 1-11, 0.46; days 11-34, 0.057; days 34-67, 0.039. 2. Total excreted nitrogen is 12.55 mg. occurring successively in development as ammonia, urea and uric acid; k value of total nitrogen production is 0.062, days 11-67, which in comparison with those of growth during this period suggest that stored protein is an energy source during a large part of development. 3. Urea is excreted into the albumen which is the principal storage reservoir and into the yolk; that which is excreted into the yolk is reabsorbed after the 45th day and re-deposited in the albumen as urea, and is in part (22%) converted to uric acid. 4. Concentration of urea in the yolk and yolk-sac continues to increase at the same rate after the 11th day (k = 0.024), although the actual amount declines after the 45th day; concentration in the embryonic tissues increases to the 58th day, then decreases sharply to hatching time; concentration in the albumen increases throughout development, reaching a concentration of approximately 500 mg.%. 5. Uric acid synthesis is believed to be preceded by urea formation, and the presence of urease in the foetal liver and kidney suggest that the urea is hydrolysed to ammonia which is then incorporated into uric acid. Site of the transformation is uncertain, though the early and persistent localization of uric acid in the chorio-allantoic membrane points to this as the organ of synthesis. Decrease in total urea content is quantitatively identical with increase in uric acid. 6. The significance of these findings in relation to development of the vertebrate cleidoic egg is discussed.

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New derivatives of xanthenone-4-acetic acid: Synthesis, pharmacological profile and effect on TNF-α and NO production by human immune cells

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2006.02.003 ◽

2006 ◽

Vol 14 (12) ◽

pp. 4101-4109 ◽

Cited By ~ 8

Author(s):

Silvia Gobbi ◽

Federica Belluti ◽

Alessandra Bisi ◽

Lorna Piazzi ◽

Angela Rampa ◽

...

Keyword(s):

Acetic Acid ◽

Immune Cells ◽

Acid Synthesis ◽

No Production ◽

Pharmacological Profile ◽

Tnf Α ◽

Human Immune ◽

Derivatives Of

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Acrylic acid synthesis by aldol condensation of acetic acid and formaldehyde on V-Ti-PO4 catalysts

Bulletin of the National Technical University «KhPI» Series New solutions in modern technologies ◽

10.20998/2413-4295.2017.32.19 ◽

2017 ◽

Vol 0 (32(1254)) ◽

pp. 117-122

Author(s):

Iryna Shpyrka ◽

Roman Nebesnyi ◽

Zorian Pikh ◽

Volodymyr Sydorchuk ◽

Volodymyr Ivasiv ◽

...

Keyword(s):

Acetic Acid ◽

Acrylic Acid ◽

Aldol Condensation ◽

Acid Synthesis

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The Distribution of Tryptophan-Dependent Indole-3-Acetic Acid Synthesis Pathways in Bacteria Unraveled by Large-Scale Genomic Analysis

Molecules ◽

10.3390/molecules24071411 ◽

2019 ◽

Vol 24 (7) ◽

pp. 1411 ◽

Cited By ~ 12

Author(s):

Pengfan Zhang ◽

Tao Jin ◽

Sunil Kumar Sahu ◽

Jin Xu ◽

Qiong Shi ◽

...

Keyword(s):

Acetic Acid ◽

Large Scale ◽

Growth Promotion ◽

Plant Root ◽

Genomic Analysis ◽

Acid Synthesis ◽

Metagenomic Data ◽

Bacterial Genomes ◽

Bacterial Phyla ◽

Indole 3 Acetic Acid

Bacterial indole-3-acetic acid (IAA), an effector molecule in microbial physiology, plays an important role in plant growth-promotion. Here, we comprehensively analyzed about 7282 prokaryotic genomes representing diverse bacterial phyla, combined with root-associated metagenomic data to unravel the distribution of tryptophan-dependent IAA synthesis pathways and to quantify the IAA synthesis-related genes in the plant root environments. We found that 82.2% of the analyzed bacterial genomes were potentially capable of synthesizing IAA from tryptophan (Trp) or intermediates. Interestingly, several phylogenetically diverse bacteria showed a preferential tendency to utilize different pathways and tryptamine and indole-3-pyruvate pathways are most prevalent in bacteria. About 45.3% of the studied genomes displayed multiple coexisting pathways, constituting complex IAA synthesis systems. Furthermore, root-associated metagenomic analyses revealed that rhizobacteria mainly synthesize IAA via indole-3-acetamide (IAM) and tryptamine (TMP) pathways and might possess stronger IAA synthesis abilities than bacteria colonizing other environments. The obtained results refurbished our understanding of bacterial IAA synthesis pathways and provided a faster and less labor-intensive alternative to physiological screening based on genome collections. The better understanding of IAA synthesis among bacterial communities could maximize the utilization of bacterial IAA to augment the crop growth and physiological function.

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A new method for the preparation of peroxymonophosphoric acid

Canadian Journal of Chemistry ◽

10.1139/v03-010 ◽

2003 ◽

Vol 81 (2) ◽

pp. 156-160 ◽

Cited By ~ 8

Author(s):

Tian Zhu ◽

Hou-min Chang ◽

John F Kadla

Keyword(s):

Hydrogen Peroxide ◽

Acetic Acid ◽

Carbon Tetrachloride ◽

Glacial Acetic Acid ◽

Acid Synthesis ◽

Conversion Ratio ◽

New Method ◽

Phosphorous Pentoxide ◽

Preparation Conditions ◽

Peroxy Acids

A new method for the preparation of peroxymonophosphoric acid (H3PO5) has been developed. It utilizes a biphasic solution to moderate the vigorous reaction between phosphorous pentoxide (P2O5) and hydrogen peroxide (H2O2). P2O5 is suspended in carbon tetrachloride (CCl4), and concentrated H2O2 is slowly added while being vigorously stirred at low temperature. Careful control of the reaction temperature through the slow addition of H2O2 is critical. Using typical preparation conditions (P2O5:H2O2 = 0.5:1, H2O2 70 wt %, 2°C, 120180 min), ~70% of the H2O2 is effectively converted to H3PO5. Increasing the concentration of H2O2, as well as the mole ratio of P2O5:H2O2, leads to an even higher % conversion of H2O2 to H3PO5. The addition of glacial acetic acid to the P2O5:H2O2 suspension at the end of the 120180 min reaction (P2O5:H2O2:CH3COOH = 0.5:1:0.3) leads to the formation of peracetic acid in addition to H3PO5, and to an overall increase in the conversion ratio of total peroxy acids based on H2O2 (>95%).Key words: peroxymonophosphoric acid, synthesis, stability, conversion ratio.

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