Oxalates

Oxalates stimulate alterations in renal epithelial cells and thereby induce calcium oxalate (CaOx) stone formation. Bacillus subtilis YvrK gene encodes for oxalate decarboxylase (OxdC) which degrades oxalate to formate and CO2. The present work is aimed to clone the oxdC gene in a mammalian expression vector pcDNA and transfect into Human Embryonic Kidney 293 (HEK293) cells and evaluate the oxdC expression, cell survival rate and oxalate degrading efficiency. The results indicate cell survival rate of HEK293/pcDNAOXDC cells pre-incubated with oxalate was enhanced by 28%. HEK293/pcDNAOXDC cells expressing OxdC treated with oxalate, significantly restored antioxidant activity, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) generation compared with HEK293/pcDNA. Apoptotic marker caspase 3 downregulation illustrates HEK293/pcDNAOXDC cells were able to survive under oxalate-mediated oxidative stress. The findings suggest HEK293 cells expressing oxdC capa...

The degradation of title dyes with ferrioxalate and H2O2 couple has been investigated spectrophotometrically. In the absence of either one of the oxidizing agents no degradation occurred. The reaction rate was proportional to moderate concentrations of the dye and H2O2. At high concentration of the dye and H2O2 the reaction rate decreased. With regard to the concentration of the ferrioxalate

Lactate dehydrogenase (LDH) isozyme 1 (B4), 5 (A4), and “X” (Testis or Sperm type) have been partially purified from mouse tissues.The following studies were carried out on the three isozymes: Km and optimum substrate concentration for pyruvate, α-oxo-butyrate, α-oxo-valerate, lactate, α-OH-butyrate, and α-OH-valerate, inhibition by substrate and product, effect of malate, N-(4-carboxy-2-hydroxyphenyl) maleimide, some citric acid cycle metabolites, urea, trypsin and pH.The mouse testicular LDH isozyme clearly differs from the common lactate dehydrogenases and from the tesficular isozymes from other species. It shows distinct sensitivity to inhibition by substrate or product whether the direct (pyruvate lactate) or reverse reactions are studied. There is no effect of increasing concentrations of pyruvate or lactate on the direct reaction, while a clear inhibition by lactate or pyruvate is demonstrated on the reverse reaction. Citric acid cycle metabolites, specially malate and succinate, inhibit the direct reaction catalyzed by the “X” isozyme.These peculiar characteristics suggest a high degree of specialization for the principal testicular isozyme of lactate dehydrogenase.

This paper presents the results of our calculations on the geometric parameters, vibrational spectra and hyperpolarizability of a nonlinear optical material l-histidine oxalate. Due to the lack of sufficiently precise information on geometric structure in literature, theoretical calculations were preceded by re-determination of the crystal X-ray structure. Single crystal of l-histidine oxalate has been growing by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in the non-Centro symmetric space group P212121 of orthorhombic system. The FT-IR and Raman spectra of l-histidine oxalate were recorded and analyzed. The vibrational wave numbers were examined theoretical with the aid of Gaussian98 package of programs using the DFT//B3LYP/6-31G(d) level of theory. The data obtained from vibrational wave number calculations are used to assign vibrational bands obtained in IR and Raman spectroscopy of the studied compound. The geometrical parameters of the title compound are in agreement with the values of similar structures. To investigate microscopic second order non-linear optical NLO behaviour of the examined complex, the electric dipole μtot, the polarizability αtot and the hyperpolarizability βtot were computed using DFT//B3LYP/6-31G(d) method. According to our calculation, the title compound exhibits non-zero βtot value revealing microscopic second order NLO behaviour.. In acid-base hybrid crystals, hydrogen bonds play an important role not only in the creation of crystal structure and its stability, but also in the enhancement of the polarizability α and the hyperpolarizability β of the crystal due to the perturbation of the electronic structure of l-histidine and also due to the strong electron–phonon coupling.► In this study, l-histidine oxalate crystallizes in the space group P212121 of orthorhombic system. ► All the experimental vibrational bands have been discussed and assigned to normal mode. ► The non linear optical properties of l-histidine oxalate have been investigated by DFT method. ► The results indicate hydrogen bonding increased the hyperpolarizability of the crystal.

This article illustrates the analysis by synchrotron micro-analytical techniques of an azurite painting presenting greenish chromatic degradation. The challenge of the experiments was to obtain the spatial distribution of the degradation products of azurite. Copper hydroxychlorides, carbonates and copper oxalates have been mapped by SR FTIR imaging of cross sections in transmission mode. To complement the information, Py/GC/MS and GC/MS techniques were applied in order to characterize the binding media and organic materials present as well as their degradation products. Results contribute to a better understanding of the decay of blue areas in ancient paintings not only from the particular point of view of azurite weathering, but also by adding information regarding the oxalates’ formation and their distribution in painting samples. Synchrotron radiation demonstrates its capability for the mapping in painting cross sections.

"For many years, plaster of Paris (gypsum: CaSO4 2H2O) was used by preparators to fill gaps in fossil bones and attach adjacent broken pieces together. Today’s preparators often find they need to remove this old plaster and replace it with modern archival materials. Plaster removal is usually done mechanically, and this process can be time-consuming and tedious. Oxalic acid provides a safe, new means to easily remove plaster of Paris from fossils.

Aqueous oxalate ions in the oxalic acid react with calcium sulfate in plaster of Paris. This reaction causes the dissolution and reformation of the plaster into calcium oxalate that is easily removed with water and minimal mechanical means. Thus, the overall preparation time can be drastically reduced.  Sulfuric acid is formed in the reaction, however. A sodium bicarbonate (baking soda) buffer can be added to the oxalic acid to neutralize the sulfuric acid production, protecting the fossil from any damage. Both the oxalic acid and baking soda are relatively inexpensive items to purchase. Therefore, oxalic acid is a time and cost-effective means of safely removing plaster of Paris from fossils.
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The work aims to estimate the oxalate ion in 5 fruits. During different stages of ripening many metal ions from insoluble precipitate with Oxalate. Oxalate rich fruits are usually restricted to some degree, particularly in patents with high urinary Oxalate Level Guava it has a highest percentage of Vitamin ’C’ among Citrus fruits. It also contains Oxalate amount of which varies with ripening of the fruit 7 fully ripe fruit has the maximum Oxalate content. Oxalate form an insoluble complex with calcium.
  Excessive intake of food drink containing Oxalate leads to calcium Oxalate stone. Also excessive intake of Vitamin ‘C’ which metabolized to Oxalate may load to hyper calcicuria and increase in stone formation. This in turn will provide an advice to take semi ripened fruits always balancing the taste of the fruit & physiological effect of affecting the kidney by oxalate content

Five oxidants, ozone, chlorine dioxide, chlorine, permanganate, and ferrate were studied with regard to the formation of assimilable organic carbon (AOC) and oxalate in absence and presence of cyanobacteria in lake water matrices. Ozone and ferrate formed significant amounts of AOC, i.e. more than 100 μg/L AOC were formed with 4.6 mg/L ozone and ferrate in water with 3.8 mg/L dissolved organic carbon. In the same water samples chlorine dioxide, chlorine, and permanganate produced no or only limited AOC. When cyanobacterial cells (Aphanizomenon gracile) were added to the water, an AOC increase was detected with ozone, permanganate, and ferrate, probably due to cell lysis. This was confirmed by the increase of extracellular geosmin, a substance found in the selected cyanobacterial cells. AOC formation by chlorine and chlorine dioxide was not affected by the presence of the cells. The formation of oxalate upon oxidation was found to be a linear function of the oxidant consumption for a...

Tender and mature leaflets and leaves of Diplazium sammatii (`Nyama idim'), were separately investigated for their nutritional and antinutritional properties. Results showed little difference in proximate nutritional contents between tender and mature leaves, except for crude fat, which was present in levels 1.5 times higher in younger than in older leaves. Crude fiber levels were low. Zinc (Zn) and copper (Cu) were higher in younger leaves (6.8 and 3.5 mg/100 g dry matter, respectively, compared to 4.5 and 2.5 mg/100 g dry matter, respectively in older leaves). Older leaves contained higher levels of iron (Fe): 6.7 mg/100 g dry matter, in comparison to 4.3mg/100 g dry matter, in young leaves. Oxalate levels were slightly higher in younger than older leaves. However, the reverse was true for tannin content. Both antinutritional compounds were present in levels which shouldbe safe.

Two bis(oxalato)cuprate(II) hybrid salts, (C5H7N2)2[Cu(C2O4)2 ]·2H2O (1) and (C7H11N 2)2 [Cu(C2O4)2 ]·5H2O (2) (C5H7N2 = 3-aminopyridinium; C7H11N2 = 2-amino-4,6-dimethylpyridinium) have been synthesized and characterized by elemental and thermal analyses, IR and UV-Vis spectroscopies, single-crystal X-ray diffraction, and SQUID magnetometry. The polymeric anionic motifs in the two salts are significantly different. In 1, stacking of [Cu(C2O4)2 ] 2-units through axial Cu···O contacts (2.890 Å) yields straight Cu(II) chains, with a prolate CuO6 octahedron around Cu(II) ions, formed by two cis-chelated oxalate anions and two axial O-atoms of neighboring [Cu(C2O4)2 ] 2-units. By contrast, in 2, stacking of [Cu(C2O4)2 ] 2-units occurs via bis-bidentate oxalate groups, yielding zigzag Cu(II) chains with a distorted CuO6 coordination sphere. Thermal studies confirmed the presence of solvent water molecules in both salts. Magnetic studies revealed weak antiferromagnetic and weak ferromagnetic interactions between Cu(II) ions in 1 and 2, respectively.