salicylates and protocatechuic-acid

Honeydew honey has differentiated chemical and physicochemical characteristics besides potential functional properties such as antimicrobial, anti-inflammatory and antioxidant. In this sense, the interest and consumption of this honey as a functional product by the food industry and consumers have increased. Honeydew honeys usually present dark color, a lower content of monosaccharides and higher values of pH, acidity, electric conductivity, proteins, minerals, phenolic compounds, and oligosaccharides compared to blossom honeys, which contribute to its outstanding biological activities. Consequently, contaminations and adulterations of this honey can occur and compromise the quality, safety and authenticity of honeydew honey. Thus, detailed knowledge of the composition and properties of honeydew honeys is of great importance, especially considering that honeydew honeys are still few studied and therefore underestimated. Therefore, in this review, the physicochemical characteristics, chemical and bioactive composition, functional and health-promoting properties of honeydew honey as well as contamination, adulteration and authenticity of this honey are summarized.

Topics: Anti-Infective Agents; Anti-Inflammatory Agents; Antioxidants; Benzoic Acid; Chemical Phenomena; Color; Coumaric Acids; Food Contamination; Food Microbiology; Glutamic Acid; Health Promotion; Honey; Hydroxybenzoates; Metals, Heavy; Phenols; Phenylalanine; Proline; Proteins; Rutin; Salicylates; Vitamins; Volatile Organic Compounds

In order to study the mechanisms regulating the phenanthrene degradation pathway and the intermediate-metabolite accumulation in strain S. paucimobilis 20006FA, we sequenced the genome and compared the genome-based predictions to experimental proteomic analyses. Physiological studies indicated that the degradation involved the salicylate and protocatechuate pathways, reaching 56.3% after 15 days. Furthermore, the strain degraded other polycyclic aromatic hydrocarbons (PAH) such as anthracene (13.1%), dibenzothiophene (76.3%), and fluoranthene. The intermediate metabolite 1-hydroxy-2-naphthoic acid (HNA) accumulated during phenanthrene catabolism and inhibited both bacterial growth and phenanthrene degradation, but exogenous-HNA addition did not affect further degradation. Genomic analysis predicted 126 putative genes encoding enzymes for all the steps of phenanthrene degradation, which loci could also participate in the metabolism of other PAH. Proteomic analysis identified enzymes involved in 19 of the 23 steps needed for the transformation of phenanthrene to trichloroacetic-acid intermediates that were upregulated in phenanthrene cultures relative to the levels in glucose cultures. Moreover, the protein-induction pattern was temporal, varying between 24 and 96 h during phenanthrene degradation, with most catabolic proteins being overexpressed at 96 h-e. g., the biphenyl dioxygenase and a multispecies (2Fe-2S)-binding protein. These results provided the first clues about regulation of expression of phenanthrene degradative enzymes in strain 20006FA and enabled an elucidation of the metabolic pathway utilized by the bacterium. To our knowledge the present work represents the first investigation of genomic, proteomic, and physiological studies of a PAH-degrading Sphingomonas strain.

Topics: Anthracenes; Bacterial Proteins; Biodegradation, Environmental; Computer Simulation; Dioxygenases; DNA, Bacterial; Fluorenes; Glucose; Hydroxybenzoates; Metabolic Networks and Pathways; Naphthols; Phenanthrenes; Polycyclic Aromatic Hydrocarbons; Proteome; Proteomics; Salicylates; Soil Microbiology; Soil Pollutants; Sphingomonas; Thiophenes; Trichloroacetic Acid; Whole Genome Sequencing

Aspergilli play major roles in the natural turnover of elements, especially through the decomposition of plant litter, but the end catabolism of lignin aromatic hydrocarbons remains largely unresolved. The 3-oxoadipate pathway of their degradation combines the catechol and the protocatechuate branches, each using a set of specific genes. However, annotation for most of these genes is lacking or attributed to poorly- or un-characterised families. Aspergillus nidulans can utilise as sole carbon/energy source either benzoate or salicylate (upstream aromatic metabolites of the protocatechuate and the catechol branches, respectively). Using this cultivation strategy and combined analyses of comparative proteomics, gene mining, gene expression and characterisation of particular gene-replacement mutants, we precisely assigned most of the steps of the 3-oxoadipate pathway to specific genes in this fungus. Our findings disclose the genetically encoded potential of saprophytic Ascomycota fungi to utilise this pathway and provide means to untie associated regulatory networks, which are vital to heightening their ecological significance.

Topics: Adipates; Aspergillus nidulans; Benzoic Acid; Catechols; Enzymes; Gene Knock-In Techniques; Genes, Fungal; Hydroxybenzoates; Lignin; Metabolic Networks and Pathways; Proteomics; Salicylates

The aim of the present study was to modify and validate a high-performance liquid chromatographic (HPLC) method for determining 2,3 and 2,5 dihydroxybenzoic acid (2,3-DHBA and 2,5-DHBA) from salicylic acid in human plasma. The mobile phase was a mixture of sodium acetate/citrate (pH 2.5) 30 mM-methanol (93:7, v/v). The injection volume was 10 muL. Retention time for 2,5-DHBA, and 2,3-DHBA was 4.5 +/- 0.10 and 5.8 +/- 0.15 min, respectively. The detection and quantification limits were 10 and 40 nM for 2,3-DHBA and 8 and 20 nM for 2,5-DHBA. Linearity was evaluated in the range of 40-1600 nM for both metabolites. Inter- and intra-analysis variation coefficient was below 10%. Good recoveries of more than 99% were obtained for both metabolites using this method.

Topics: Biomarkers; Catechols; Chromatography, High Pressure Liquid; Drug Stability; Gentisates; Humans; Hydroxybenzoates; Hydroxylation; Linear Models; Oxidative Stress; Reproducibility of Results; Salicylates; Sensitivity and Specificity

We have investigated the mechanism of reduction of organically complexed iron(III) in the presence of superoxide, the one-electron reduced form of dioxygen that is produced in natural waters by thermal, photochemical, and biological pathways. Experimental results show that reduction of organically complexed iron(III) by superoxide may occur by either (or, in some instances, both) reaction of superoxide with inorganic iron(III) after its dissociation from the complex (dissociative reduction) or by direct reaction of superoxide with the complex (non-dissociative reduction). In the presence of low concentrations of ligands such as citrate and sulfosalicylate that bind iron(III) relatively weakly and result in complexes with high dissociation rate constants (kd > 1 x 10(-4) s(-1)), a dissociative reduction pathway dominates. However, in the presence of strong ligands or high concentrations of weak ligands, only non-dissociative reduction of complexed iron(III) occurs. The relative contribution of each pathway has major implications for the lability and hence potential bioavailablity of iron in natural waters. The simple kinetic model developed here can be used to correctly predict the superoxide-mediated formation rates of iron(II) in natural systems.

Topics: Benzenesulfonates; Benzopyrans; Citrates; Deferoxamine; Edetic Acid; Ferrozine; Hydroxybenzoates; Iron; Oxidation-Reduction; Salicylates; Siderophores; Superoxides

The equilibrium reactions of yttrium(III) ion with dihydroxybenzoic acids (2,3-dihydroxybenzoic acid (2,3-DHBA) and 3,4-dihydroxybenzoic acid (3,4-DHBA)) (H(3)L) were investigated in aqueous solution by means of potentiometric and spectroscopic methods, in 0.1 mol.l(-1) ionic strength medium at 25 degrees C. The stability constants are reported for YL, YL(HL)(2-) and YL(2)(3-)- type mononuclear complexes. 2,3-DHBA can bind Y(III) ion strongly and the salicylate mode is effective over the acidic pH range. But in higher pH range, 2,3-DHBA and 3,4-DHBA act more efficiently through catecholate groups. The complexes of 2,3-DHBA are more stable than the complexes of 3,4-DHBA.

Topics: Hydrogen-Ion Concentration; Hydrolysis; Hydroxybenzoates; Indicators and Reagents; Potentiometry; Salicylates; Spectrophotometry, Ultraviolet; Yttrium

The detection of reactive oxygen species (ROS) after traumatic brain injury (TBI) is based on indirect methods due to the high reactivity and short half-life of ROS in biological tissue. The commonly used salicylate trapping method has several disadvantages making it unsuitable for human use. We have evaluated 4-hydroxybenzoic acid (4-HBA) together with microdialysis (MD) in the rat as an alternative method. 4-HBA forms one stable adduct, 3,4-dihydroxybenzoic acid (3,4-DHBA), when reacting with ROS and has not previously been used together with MD after TBI. Twenty-seven rats were used for the assessment of 3,4-DHBA production as an indicator of ROS formation in a controlled contusion injury model using intracerebral MD with 3 mM 4-HBA in the perfusate. For comparison, salicylate trapping was used in eight rats. TBI caused a 250% increase of 3,4-DHBA that peaked at 30 min after injury in severely injured rats and remained significantly elevated as compared to baseline for 90 min after trauma. The mild injury level caused a 100% increase in 3,4-DHBA formation at 30 min after the injury. When the MD probe was placed in the perimeter of the injury site, no significant increase in ROS formation occurred. Salicylate trapping showed a similar increase in adduct formation after severe injury. In addition, high cortical concentrations of 4-HBA and salicylate were found. It is concluded that microdialysis with 4-HBA as a trapping agent appears to be a useful method for ROS detection in the rat with a potential clinical utility.

Topics: Animals; Blood Pressure; Body Temperature; Brain; Brain Injuries; Chromatography, High Pressure Liquid; Functional Laterality; Hydroxybenzoates; Male; Microdialysis; Parabens; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Salicylates; Spin Trapping

A Moraxella sp. strain VG45 capable of utilizing o-phthalate and salicylate as a sole source of carbon and energy was isolated. The degradation of o-phthalate occurs via phthalate 4,5-dioxygenase, 4,5-dihydro-4,5-dihydroxyphthalate dehydrogenase, 4,5-dihydroxyphthalate decarboxylase and protocatechuate 4,5-dioxygenase. Salicylate is degraded via salicylate 5-hydroxylase, gentisate 1,2-dioxygenase and then by a glutathione-independent maleylpyruvate hydrolase. Further, a plasmid of app. 60 kilobase pairs (kb) is involved in the degradation of the o-phthalate and salicylate and the enzymes of these two pathways are independently regulated in strain VG45.

Topics: Biodegradation, Environmental; Dioxygenases; Hydroxybenzoates; Mixed Function Oxygenases; Moraxella; Oxidoreductases; Oxygenases; Phthalic Acids; Plasmids; Salicylates; Salicylic Acid

An improved chemometric approach is proposed for assessing chromatographic peak purity by means of artificial neural networks. A non-linear transformation function with a back-propagation algorithm was used to describe and predict the chromatographic data. The Mann-Whitney U-test was used for the concluding the purity of the chromatographic peak. Simulation data and practical analytical data for both pure and mixture samples were analysed with satisfactory results. A prior knowledge of the impurity and the related compound is unnecessary when a slight difference between their chromatogram and spectrum exists. The performance on simulated data sets by this approach was compared with the results from principal component analysis.

Topics: Algorithms; Caffeic Acids; Chromatography; Hydrogen-Ion Concentration; Hydroxybenzoates; Neural Networks, Computer; Parabens; Salicylates; Salicylic Acid

Rhodococcus erythropolis strain S1 uses the gentisate pathway to metabolize salicylate and m-hydroxybenzoate and the protocatechuate pathway to degrade p-hydroxybenzoate. m-Hydroxybenzoate 6-hydroxylase was induced by growth on m-hydroxybenzoate or gentisate, and salicylate 5-hydroxylase only by growth on salicylate. p-Hydroxybenzoate 3-hydroxylase could be induced only by growth on p-hydroxybenzoate. m-Hydroxybenzoate or p-hydroxybenzoate could repress the induction of salicylate 5-hydroxylase. Maleylpyruvate isomerase in the gentisate pathway did not require reduced glutathione.

Topics: cis-trans-Isomerases; Gentisates; Glutathione; Hydroxybenzoates; Isomerases; Kinetics; Mixed Function Oxygenases; Oxygen Consumption; Parabens; Rhodococcus; Salicylates; Salicylic Acid