2-2--azino-di-(3-ethylbenzothiazoline)-6-sulfonic-acid and 1-2-diaminobenzene

Novel Fe

Topics: Benzidines; Benzothiazoles; Biosensing Techniques; Carbon; Catalysis; Chromogenic Compounds; Colorimetry; Dopamine; Humans; Hydrogen Peroxide; Limit of Detection; Magnetite Nanoparticles; Manganese Compounds; Metal-Organic Frameworks; Oxidation-Reduction; Oxides; Phenylenediamines; Sulfonic Acids

In this paper, ferrocene derivative polymer nanoparticles (FcP NPs) with uniform size and good photostability was synthesized using 1,1'-ferrocene dicarboxylic acid as precursor and methanol as solvent. FcP NPs-PDA was further obtained by coating of polydopamine (PDA) on FcP NPs in tris-HCl (pH=8.5) buffer solution at room temperature in the presence of dopamine (DA). The structure and morphology of FcP NPs and FcP NPs-PDA were characterized by transmission electron microscope (TEM), ultraviolet-visible spectroscopy (UV-Vis), and infrared radiation (FT-IR). The as-prepared FcP NPs-PDA showed better peroxidase-like activity than FcP NPs, which could catalyze the chromogenic reaction of peroxidase substrate TMB, OPD and ABTS. Based on the high peroxidase-like property of FcP NPs-PDA, a sensitive and convenient means to detect H

Topics: Benzidines; Benzothiazoles; Biomimetics; Catalysis; Ferrous Compounds; Metallocenes; Nanocomposites; Nanoparticles; Peroxidase; Phenylenediamines; Polymers; Sulfonic Acids

Efficient hydrogen peroxide detoxification is an essential aspect of plant defence against a large variety of stressors. Among others, class III peroxidase (POD, EC 1.11.1.7) enzymes provide this function. Previous studies have shown that PODs are present in several isoforms and have in general low substrate specificities. The aim of our work was to study how various assays based on using various substrates reflect differences in peroxidase activities of tobacco leaves due to either developmental or environmental factors. The former factor was studied comparing fully developed leaves of the 3rd and 5th nodes; and the latter was achieved using plants acclimated to low doses of supplementary UV-B (280-315 nm) in growth chambers. To investigate the above, POD activities were measured using three different, commonly used chromophore substrates: ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), guaiacol (2-methoxyphenol), OPD (o-phenylenediamine) and a fourth substrate, the secondary metabolite quercetin. All substrates registered a UV-B induced increase in leaf peroxidases as compared to untreated controls, although to different extents. However, age-related differences between upper and lower leaves were only detectable when either ABTS or quercetin were used as substrates. Additionally, native PAGE separation of POD isoforms followed by visualisation using one of the substrates showed that leaf acclimation to supplementary UV-B is realized via a selective activation of POD isoforms.

Topics: Antioxidants; Benzothiazoles; Guaiacol; Isoenzymes; Nicotiana; Peroxidases; Phenylenediamines; Plant Leaves; Plant Proteins; Quercetin; Sulfonic Acids; Ultraviolet Rays

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

The author tested the suitability of various chromogens in ELISA systems with horseradish peroxidase. As a model he used assessment of human chorionic gonadotropin (HCG). The author evaluated the influence of substrate concentration on the resulting colour reaction and the influence of the presence of a detergent on the peroxidase activity. He investigated also the advantages of the used chromogens with regard to the accuracy and sensitivity of the estimation.

Topics: Benzothiazoles; Chorionic Gonadotropin; Chromogenic Compounds; Enzyme-Linked Immunosorbent Assay; Horseradish Peroxidase; Humans; Phenylenediamines; Sulfonic Acids

A micro-technique of enzyme-linked immunosorbent assay (ELISA) using ABTS, 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid), as a substrate for horseradish peroxidase (HRP) conjugate was studied. In a comparative study among 4 substrates, namely; 5-aminosalicylic acid (5AS), O-phenylenediamine (OPD), O-tolidine (OT) and ABTS, for HRP in terms of sensitivity, it was found that ABTS was the most sensitive, stable and the best in visuality by its bluish-green color. The precise reproducibility of ELISA readings was attained by making correction of observed absorbance with positive reference serum. Sera from 50 patients positive for S. japonicum (Sj) egg and from 50 healthy residents in non-infested areas were diluted at 1:200 and examined by this procedure of ELISA against crude egg antigen. The upper limit of 99% critical range of the absorbance among negative sera was 0.080. The reactions of egg positive cases were beyond this value, being 0.505 at the minimal absorbance (1.259 +/- 0.278), and were easily distinguished from negatives even by naked eyes. Cross-reactivity to Sj egg antigen was studied using sera from 75 cases with 22 kinds of varied parasitic infections. Among them, S. mansoni and S. haematobium infections showed higher absorbance while the others did a little higher than the normal range. The highest absorbance shown by a Trichobilharzia brevis case was 0.177. The results indicated that micro-ELISA technique with ABTS developed in the present study is applicable to the field survey because of its high sensitivity, specificity and reproducibility.

Topics: Aminosalicylic Acids; Animals; Benzidines; Benzothiazoles; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Female; Horseradish Peroxidase; Humans; Mesalamine; Mice; Ovum; Peroxidases; Phenylenediamines; Schistosomiasis; Sulfonic Acids