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Chemistry & Biodiversity Dec 2023The aim of this study was to examine a collection of 79 honeys derived from plants endemic to several Western Australian unique bioregions for bioactivity and...
The aim of this study was to examine a collection of 79 honeys derived from plants endemic to several Western Australian unique bioregions for bioactivity and physicochemical characteristics. For physicochemical analyses, total phenolic content, high performance thin layer chromatography (HPTLC) fingerprints, pH, Brix, colour and hydrogen peroxide generation were examined. Brix (82.6±1.3) and pH (4.34±0.24) values were within expected ranges, whereas hydrogen peroxide levels determined using an o-dianisidine/horseradish peroxidase assay were relatively low, ranging from 0-244 μM. Antibacterial activity determined by the broth microdilution assay showed that Moort (Eucalyptus platypus) and Yate (Eucalyptus occidentalis) honeys had the highest overall activity with mean minimum inhibitory concentrations of 24.8 % and 25.1 % (w/v) honey, respectively. Yate honey also had the highest overall antioxidant activity (4.38±0.58 mmol Fe /kg of honey), followed by Mallee honeys from various eucalypts, as determined by FRAP (Ferric reducing antioxidant power) and DPPH⋅ (2,2-Diphenyl-1-picrylhydrazyl) assays. This study identified new sources of honeys with potentially useful therapeutic properties from bioregions within Western Australia.
Topics: Western Australia; Honey; Hydrogen Peroxide; Australia; Phenols; Antioxidants; Eucalyptus
PubMed: 37968896
DOI: 10.1002/cbdv.202301678 -
Chemosphere Aug 2017The risk of acetochlor to human health is still unclear, prompting concern over its risk, especially to pesticide suicides population, occupational population (farmers,...
The risk of acetochlor to human health is still unclear, prompting concern over its risk, especially to pesticide suicides population, occupational population (farmers, retailers and pharmaceutical workers), and special population (young children and infants, pregnant women, older people, and those with compromised immune systems). This study was to explore the toxic effect and the possible mechanism of toxic action of acetochlor using zebrafish larvae whose toxicity profiles have been confirmed to be strikingly similar with mammalian. The result indicated that the toxic target organ of acetochlor was cardiovascular system. Thus, cardiovascular toxicity evaluation was investigated systematically. The main phenotypes of cardiovascular toxicity induced by acetochlor were bradycardia, pericardial edema, circulation defect, and thrombosis; Malformed heart was confirmed by histopathological examination. Thrombosis which maybe triggered by bradycardia was further studied using o-dianisidine for erythrocyte staining; Substantial thrombus in the caudal vein and significantly reduced heart red blood cells (RBCs) intensity which can reflect the thrombosis degree were observed in zebrafish in a concentration-dependent manner. Additionally, the mRNA expression level of Nkx2.5 and Gata4 related to induction of cardiac program were down-regulated significantly by quantitative real-time polymerase chain reaction (qRT-PCR), which could cause defects in the cardiovascular system. For the first time, our results demonstrated that acetochlor induced cardiovascular toxicity, and down-regulation of Nkx2.5 and Gata4 might be its possible molecular basis. Our data generated here might provide novel insights into cardiovascular disease risk following acetochlor exposure to human, especially to pesticide suicides population, occupational population and special population.
Topics: Animals; Cardiovascular System; Down-Regulation; GATA Transcription Factors; Herbicides; Homeobox Protein Nkx-2.5; Humans; Larva; RNA, Messenger; Toluidines; Zebrafish; Zebrafish Proteins
PubMed: 28472748
DOI: 10.1016/j.chemosphere.2017.04.090 -
Chemistry (Weinheim An Der Bergstrasse,... Feb 2006Carbonic anhydrase is a zinc metalloenzyme that catalyzes the hydration of carbon dioxide to bicarbonate. Replacing the active-site zinc with manganese yielded...
Carbonic anhydrase is a zinc metalloenzyme that catalyzes the hydration of carbon dioxide to bicarbonate. Replacing the active-site zinc with manganese yielded manganese-substituted carbonic anhydrase (CA[Mn]), which shows peroxidase activity with a bicarbonate-dependent mechanism. In the presence of bicarbonate and hydrogen peroxide, (CA[Mn]) catalyzed the efficient oxidation of o-dianisidine with kcat/KM=1.4 x 10(6) m(-1) s(-1), which is comparable to that for horseradish peroxidase, kcat/KM=57 x 10(6) m(-1) s(-1). CA[Mn] also catalyzed the moderately enantioselective epoxidation of olefins to epoxides (E=5 for p-chlorostyrene) in the presence of an amino-alcohol buffer, such as N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES). This enantioselectivity is similar to that for natural heme-based peroxidases, but has the advantage that CA[Mn] avoids the formation of aldehyde side products. CA[Mn] degrades during the epoxidation limiting the yield of the epoxidations to <12 %. Replacement of active-site residues Asn62, His64, Asn67, Gln92, or Thr200 with alanine by site-directed mutagenesis decreased the enantioselectivity demonstrating that the active site controls the enantioselectivity of the epoxidation.
PubMed: 16416502
DOI: 10.1002/chem.200501413 -
Archives of Environmental Health May 1961
Biotransformation of the benzidines. III. Studies on diorthotolidine, dianisidine, and dichloro-benzidine: 3, 3' disubstituted congeners of benzidine (4, 4'-diaminobiphenyl).
Topics: Benzidines; Biotransformation; Biphenyl Compounds; Dianisidine; Hydrocarbons, Halogenated
PubMed: 13749284
DOI: 10.1080/00039896.1961.10662906 -
American Journal of Clinical Pathology Dec 1964
Topics: Blood Chemical Analysis; Blood Coagulation; Dianisidine; Hot Temperature; Humans; Oxidation-Reduction; Research; Spectrophotometry; Uric Acid
PubMed: 14239442
DOI: 10.1093/ajcp/42.6_ts.630 -
Technical Bulletin of the Registry of... Nov 1964
Topics: Biphenyl Compounds; Blood; Blood Coagulation; Colorimetry; Dianisidine; Hot Temperature; Humans; Oxidation-Reduction; Uric Acid
PubMed: 14222338
DOI: No ID Found -
International Journal of Biological... Dec 2011The concentration and time-dependences and the mechanism of the inactivation of Chamaerops excelsa peroxidase (CEP) by hydrogen peroxide were studied kinetically with...
The concentration and time-dependences and the mechanism of the inactivation of Chamaerops excelsa peroxidase (CEP) by hydrogen peroxide were studied kinetically with four co-substrates (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), guaiacol, o-dianisidine and o-phenylenediamine). The turnover number (r) of H(2)O(2) required to complete the inactivation of the enzyme varied for the different substrates, the enzyme most resistant to inactivation (r=4844) with ABTS being the most useful substrate for biotechnological applications, opening a new avenue of enquiry with this peroxidase.
Topics: Arecaceae; Benzothiazoles; Biotechnology; Chromatography; Dianisidine; Electrophoresis, Polyacrylamide Gel; Guaiacol; Hydrogen Peroxide; Hydrogen-Ion Concentration; Kinetics; Models, Chemical; Oxidation-Reduction; Peroxidase; Phenylenediamines; Plant Leaves; Plant Proteins; Solutions; Substrate Specificity; Sulfonic Acids
PubMed: 21925205
DOI: 10.1016/j.ijbiomac.2011.09.001 -
Bulletin of Experimental Biology and... May 2020A novel express method is developed to determine activity of antitumor enzyme L-lysine-α-oxidase obtained by culturing Trichoderma harzianum Rifai F-180 fungus. The...
A novel express method is developed to determine activity of antitumor enzyme L-lysine-α-oxidase obtained by culturing Trichoderma harzianum Rifai F-180 fungus. The carcinogenic reagent ortho-dianisidine-hydrochloride was replaced in the reaction medium with environmentally friendly reagents of the chromogenic mixture that included tetramethylbenzidine. This method improved precision and sensitivity of ELISA by 10 and 40 times, respectively. In addition, it could detect activity of L-lysine-α-oxidase not only in the producer strains with a pronounced activity of this enzyme, but also in the strains where this activity has not been previously determined.
Topics: Amino Acid Oxidoreductases; Antineoplastic Agents; Colorimetry; Culture Media; Drug Screening Assays, Antitumor; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hypocreales; Temperature; Time Factors
PubMed: 32488773
DOI: 10.1007/s10517-020-04837-2 -
Bio-protocol Jul 2023Myeloperoxidase (MPO) is an enzyme contained in lysosomal azurophilic granules of neutrophils. MPO activity has been shown to correlate with the number of neutrophils in...
Myeloperoxidase (MPO) is an enzyme contained in lysosomal azurophilic granules of neutrophils. MPO activity has been shown to correlate with the number of neutrophils in histological sections of the gastrointestinal tract and is therefore accepted as a biomarker of neutrophil invasion in the gut. This protocol describes an easy, cost-effective kinetic colorimetric assay to quantify myeloperoxidase activity in intestinal tissue samples. It is explained using tissue collected in mice but can also be used for other laboratory animals. In a first step, tissue specimens are homogenized using a phosphate buffer containing 0.5% hexadecyltrimethylammonium bromide (HTAB), which extracts MPO from neutrophils. The obtained supernatant is added to a reagent solution containing o-dianisidine dihydrochloride, which is a peroxidase substrate. Finally, the change in absorption is measured via spectrophotometry and converted to a standardized unit of enzyme activity. The assay is illustrated and compared to a commercially available enzyme-linked immunoassay (ELISA), demonstrating that MPO activity does not necessarily correlate with MPO protein expression in tissue samples. Key features Optimized for use in mice and rats but can also be used for samples of other species. Measures enzymatic activity instead of mRNA or protein expression. Requires a spectrophotometer. Can be performed in duplo using 10 mg of (dry-blotted) gut tissue or more. Graphical overview.
PubMed: 37456337
DOI: 10.21769/BioProtoc.4758 -
Physiology and Molecular Biology of... Apr 2011The Santalum peroxidase was extracted from the leaves and precipitated with double volume of chilled acetone. The optimum percent relative activity for the Santalum...
The Santalum peroxidase was extracted from the leaves and precipitated with double volume of chilled acetone. The optimum percent relative activity for the Santalum peroxidase was observed at pH 5.0 and 50 °C temperature. The Santalum peroxidase per cent relative activity was stimulated in the presence of phenolic compounds like ferrulic acid and caffeic acids; however, indole-3-acetic acid (IAA) and protocatechuic acid act as inhibitors. All divalent cations Fe(2+), Mn(2+), Mg(2+), Cu(2+) and Zn(2+) stimulate the relative activity of the Santalum peroxidase at concentration of 2.0 μM. Amino acids like L-alanine and L-valine activate the per cent relative activity, while L-proline and DL-methionine showed moderate inhibition for the Santalum peroxidase. However, a very low a concentration of cysteine acts as a strong inhibitor of Santalum peroxidase at the concentration of 0.4 mM. Native polyacrylamide gel electrophoresis (Native-PAGE) was performed for isoenzyme determination and two bands were observed. Km and Vmax values were calculated from Lineweaver-Burk graph. The apparent Vmax/Km value for O-dianisidine and H2O2 were 400 and 5.0 × 105 Units/min/mL respectively.
PubMed: 23573005
DOI: 10.1007/s12298-011-0054-x