oxalates and tartaric-acid

Physiological properties involved in cadmium (Cd) transport were investigated in the high Cd accumulating rice line (Lu527-8) in comparison with the normal rice line (Lu527-4) through a soil culture experiment. The results showed that Cd contents in xylem saps of Lu527-8 were 1.68-2.55 times higher than those of Lu527-4 under Cd stress. A high-positive correlation between Cd contents in xylem saps and Cd contents in shoots was observed. Lu527-8 owned a more rapid and effective transport of Cd to above-ground part. By analyzing the relationship between inorganic anions, organic components and Cd contents in xylem saps, the lower HPO

Topics: Cadmium; Citric Acid; Histidine; Oryza; Oxalates; Phosphates; Plant Development; Plant Roots; Soil; Soil Pollutants; Stress, Physiological; Tartrates; Xylem

Acid content is one of the important quality attributes in determining the maturity index of agricultural product, particularly fruits. Despite the fact that much research on the measurement of acidity in fruits through non-destructive spectroscopy analysis at NIR wavelengths between 700 to 1,000 nm has been conducted, the same response towards individual acids is not well known. This paper presents NIR spectroscopy analysis on aqueous citric, tartaric, malic and oxalic solutions through quantitative analysis by selecting a set of wavelengths that can best be used to measure the pH of the solutions. The aquaphotomics study of the acid solutions has generated R² above 0.9 for the measurement of all acids. The most important wavelengths for pH are located at 918-925 nm and 990-996 nm, while at 975 nm for water.

Topics: Acids; Citric Acid; Fruit; Hydrogen-Ion Concentration; Malates; Oxalates; Solutions; Spectroscopy, Near-Infrared; Tartrates

Class D beta-lactamases represent a heterogeneous group of active-site serine beta-lactamases that show an extraordinary panel of functional features and substrate profiles, thus representing relevant models for biochemical and structural studies. OXA-46 is a narrow-spectrum enzyme belonging to the OXA-2 subgroup which was found in a Pseudomonas aeruginosa clinical isolate from northern Italy. In this work, we obtained the three-dimensional structure of OXA-46, which shows the overall fold of active serine beta-lactamases and a dimeric quaternary structure. Significant differences with currently available structures of class D beta-lactamases were found in the loops located close to the active site, which differ in length and conformation. Interestingly, the three subunits present in the asymmetric unit showed some structural heterogeneity, only one of which presented a carbamylated lysine recognized as an important functional feature of class D enzymes. The carbamylation state of residue Lys75 appeared to be associated with different shapes and dimensions of the active site. Moreover, a tartrate molecule from the crystallization buffer was found in the active site of the noncarbamylated subunits, which interacts with catalytically relevant residues. The OXA-46 crystal asymmetric units thus interestingly present the structures of the free carbamylated active site and of the ligand-bound uncarbamylated active site, offering the structural basis for investigating the potential of new scaffolds of beta-lactamase inhibitors.

Topics: Amino Acid Sequence; Anions; beta-Lactam Resistance; beta-Lactamases; Carboxylic Acids; Catalytic Domain; Conserved Sequence; Crystallography, X-Ray; Lysine; Molecular Sequence Data; Oxalates; Protein Structure, Quaternary; Protein Structure, Secondary; Protein Structure, Tertiary; Pseudomonas aeruginosa; Structure-Activity Relationship; Tartrates

Potassium salts in desensitising formulations are believed to act by blocking nerve conduction. The aim of this study was to assess the ability of some organic potassium salts to block action potential conduction and to compare their effects with potassium chloride and potassium nitrate.. Potassium citrate, oxalate or tartrate were added to Krebs' solutions to raise the potassium concentration to 8-64 mM. The test solutions were applied to rat spinal nerves in a bath while monitoring the compound action potentials evoked by electrical stimulation.. All potassium salts attenuated the compound action potential in a dose-dependent manner. There were no significant differences between the effects of potassium tartrate and potassium citrate solutions (p>0.1) which caused significantly greater compound action potential attenuation than the same concentrations of potassium oxalate (p<0.05). On the basis of the potassium ion concentration required to cause 50% attenuation of the compound nerve action potential, the relative potencies of the potassium salts were: citrate = tartrate> oxalate>chloride =nitrate.. Potassium citrate and potassium tartrate were more effective than other potassium salts in blocking nerve conduction and may be more effective dentinal desensitising agents.

Topics: Action Potentials; Aluminum; Anesthetics, Local; Animals; Calcium; Citrates; Dentin Sensitivity; Dose-Response Relationship, Drug; Electric Stimulation; Evoked Potentials; Isotonic Solutions; Male; Nerve Block; Neural Conduction; Osmolar Concentration; Oxalates; Potassium Citrate; Rats; Rats, Wistar; Sodium Citrate; Spinal Nerve Roots; Tartrates

Magnesium and tartrate each reduce calcium oxalate crystal formation in urine. Since the effects are additive, a palatable mixture of magnesium and tartrate salts was devised and fed to 6 healthy volunteers. There were no side effects. There was a moderate fall in urinary calcium, moderate rises in urinary magnesium, tartrate and citrate, and no change in urinary oxalate. Hence there are good grounds for supposing that this mixture could be used to prevent urinary stone recurrence.

Topics: Calcium; Carbonates; Citrates; Citric Acid; Drug Combinations; Humans; Magnesium; Oxalates; Oxalic Acid; Potassium; Tartrates; Urinary Calculi

Oxalic acid was separated from interfering compounds with a solvent-generated ion-exchange chromatographic system, and detected with a copper electrode amperometric detector. The lower limit of detection in standard solutions was 5 ng. Complex samples, such as vegetable extracts and urine, could be analysed with a minimum of sample preparation.

Topics: Cetrimonium Compounds; Chemical Phenomena; Chemistry; Chromatography, Ion Exchange; Chromatography, Liquid; Electrodes; Humans; Indicators and Reagents; Malates; Malonates; Oxalates; Oxalic Acid; Phenylalanine; Tartrates; Vegetables

With reference to a critical publication by F. Ehrhardt (1780), the author presents and analyses all documents concerning the discovery of tartaric, oxalic and phosphoric acids in animal earth (from bones or hartshorn, Cornu cervi). Furthermore, he dates Scheele's manuscripts Nos 22 to 41 from Oseen's collection, and draws conclusions as to Scheele's studies on fluorspar and to Scheele's acquaintance (1770) with J.G. Gahn and T. Bergman.

Topics: Acids; History, 18th Century; Oxalates; Oxalic Acid; Phosphoric Acids; Soil; Tartrates

Topics: Aminophenols; Aminosalicylic Acid; Aminosalicylic Acids; Chemistry, Pharmaceutical; Chromatography; Chromatography, Thin Layer; Mesalamine; Oxalates; Oxalic Acid; Phenols; Sodium; Tartrates

Topics: Fumarates; Maleates; Oxalates; Oxalic Acid; Tartrates

Topics: Citrates; Citric Acid; Iron; Oxalates; Polarography; Tartrates