Effect Of Resorcinol Research Articles

The Effect of Resorcinol on the Kinetics of Underpotentially Deposited Hydrogen and the Oxygen Evolution Reaction, Studied on Polycrystalline Pt in a 0.5 M H2SO4 Solution

This article reports on the influence of resorcinol (RC) on the kinetics of underpotential deposition of hydrogen (UPD of H) and the oxygen evolution reaction (OER), studied on a polycrystalline Pt electrode in a 0.5 M sulphuric acid supporting solution. It is well known that both PEM fuel cells and water electrolysers’ electrodes often contain significant amounts of nanostructured Pt or other types of noble metal particles. These materials provide the superior catalytic activity of electrochemical reactions such as OER (oxygen evolution reaction), HER (hydrogen evolution reaction) and ORR (oxygen reduction reaction). The trace amounts of phenolic substances contained in air or water could be harmful (when in contact with a fuel cell/water electrolyser’s working environment) to the abovementioned catalytic surfaces. Hence, they could potentially have severe detrimental effects on the kinetics of these processes. The results obtained in this work provided evidence for the detrimental role of Pt surface-adsorbed resorcinol molecules (or their electrodegradation products) on the kinetics of UPD of H and the oxygen evolution reaction. The above was revealed through evaluation of the associated charge-transfer resistance and capacitance parameters, comparatively derived on a platinum electrode, for the initial and the resorcinol-modified H2SO4 electrolyte.

Revealing the binding properties between resorcinol and DNA

Resorcinol (1,3-dihydroxybenzene) is a common coupling agent in permanent hair dyes, and has arrested people's attention for its potential hazard to human health. However, the action mechanism of resorcinol and human DNA has not been elucidated. In this research, the binding properties between resorcinol and calf thymus DNA (ct-DNA) were studied for the first time through various spectral and molecular docking techniques. Spectral studies showed that the initial fluorescence quenching of resorcinol against DNA was a static one. The result of ΔH < 0 and ΔS > 0 was produced from thermodynamic experimental data, therefore it could be concluded that electrostatic force was the major driving force, while binding constant Kb was 1.56 × 104 M-1 at 298 K. The electrostatic binding network between resorcinol and ct-DNA was established explicitly through competitive substitution analysis and other spectral approaches. The results of FT-IR absorption spectra indicated that resorcinol had bound to the DNA phosphate skeleton. Molecular docking clearly revealed that binding occurred between hydroxyl groups of resorcinol and phosphorus oxygen bonds (P-O) of the DNA skeleton. These findings may deepen our understanding of the action mechanism between resorcinol and ct-DNA and provide some useful data on the effect of resorcinol on human diseases.

IN VITRO EFFECT OF RESORCINOL ON BOVINE SPERMATOZOA IN PROCESS OF CRYOPRESERVATION

The purpose of present study was to observe the effect of resorcinol on bovine spermatozoa before and after cryopreservation. Fresh semen was obtained from six randomly chosen breeding bulls. Experimental samples were prepared by diluting the semen with six different concentrations of resorcinol (REZ1– 4; REZ2 – 2; REZ3 – 1; REZ4 – 0.5; REZ5 – 0.25 and REZ6 –0.152 mg.ml-1). Experimental groups were compared against control group (REZK). Using CASA method spermatozoa motility was evaluated before cryopreservation and also after thawing, during incubation at 37°C in time periods 0, 5, 10, 15 and 60 minutes. Negative effect of in vitro resorcinol addition was observed in all analysed parameters (MOT, PRO, VCL, ALH and BCF) in groups REZ1, REZ2 and REZ3. In contrast, positive impact mainly on motility and progressive motility was found in experimental groups with the lowest resorcinol concentration addition (REZ4, REZ5 and REZ6) in comparison to the control group. After thawing significant effect of resorcinol on motility parameters were observed within each experimental group. Group with the highest concentration of resorcinol (REZ1) had markedly negative impact on evaluated motility parameters. Results of our study clearly confirm toxic effect of resorcinol on motility parameters of spermatozoa, which depend on concentration and time period.

Synergistic Effect of Cl−, Br−and I−on the Corrosion Inhibition of Mild Steel in H2SO4 by a Resorcinol: Kinetics and Thermodynamic Studies

The synergistic effect between resorcinol and halides on the corrosion of mild steel in 0.5 M H2SO4 solution at 298K is done by mass loss method. Experimental results revealed the pointing synergistic activity of halides on the protective effect of resorcinol. The effect of halides on the inhibition efficiency obey the trend: Cl−< Br−< I. This trend shows that the radii and electronegativity of the halide play a predominant role in the adsorption process. In contrary the synergism obey the opposite order due to the effective inhibition efficiency of iodide. The adsorption of the resorcinol follows the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters also calculated and discussed.

Enhancement of Fenton and photo-Fenton processes at initial circumneutral pH for the degradation of the β-blocker metoprolol

The need for acidification in the Fenton and photo-Fenton process is often outlined as one of its major drawbacks, thus in this work the acidification of the Metoprolol (MET) is avoided by the addition of resorcinol (RES), which is used to simulate model organic matter. The experiments were carried out at natural pH (6.2) with different Fe2+ (1, 2.5, 5, and 10 mg/L) and H2O2 (25, 50, 125 and 150 mg/L) concentrations. The performance of MET and RES degradation was assessed along the reaction time. Working with the highest concentrations (5 and 10 mg/L of ferrous iron and 125 and 150 mg/L of H2O2) more than 90% of MET and RES removals were reached within 50 and 20 min of treatment, respectively, by Fenton process. However a low mineralization was achieved in both cases, likely, due to by-products accumulation. Regarding to photo-Fenton process, within 3 min with the highest iron and hydrogen peroxide concentrations, a complete MET degradation was obtained and 95% of RES conversion was achieved. Parameters such Total Organic Carbon, Chemical Oxygen Demand, and AOS were measured. Intermediates were identified and MET degradation path was proposed in the presence of resorcinol. Finally, a comparison between Fenton and photo-Fenton processes at acid pH and at initial circumneutral pH was discussed. The positive effect of RES on Fenton and photo-Fenton systems has been confirmed, allowing the work at circumneutral pH.

Solar photo-Fenton for water disinfection: An investigation of the competitive role of model organic matter for oxidative species

The competitive effect for the oxidative species produced during solar photo-Fenton process at neutral pH between an organic compound (resorcinol) and a model microorganism (Enterococcus faecalis) was investigated. With this purpose, the inactivation of E. faecalis was evaluated under several solar processes, i.e. SODIS, solar-UVA with H2O2 (10, 20 and 50mgL−1) and solar-UVA-Fe2+ (2.5, 5 and 20mgL−1) in the absence and presence of resorcinol (10mgL−1). The effect of resorcinol on the Fenton reaction (H2O2/Fe2+ in the dark: 5/2.5 and 50/20mgL−1) efficacy at neutral pH was also evaluated. In spite of resorcinol maintained a high amount of iron (around 10mgL−1) in solution during the experiments, with the highest concentrations of H2O2/Fe2+ (50/20mgL−1), only a 2-log decrease of bacteria was observed with 10mgL−1 of resorcinol, while a 3.5-log abatement was detected without resorcinol. These results highlight the competitive role of organic matter for the oxidant species against bacteria when photo-oxidation and photo-disinfection processes are occurring at the same time. This competition for the oxidant species, mainly hydroxyl radicals generated during photo-Fenton, was confirmed by (i) the solar photo-Fenton assays at three different concentrations (H2O2/Fe2+): 5/2.5, 10/5 and 20/10mgL−1, although at elevated concentrations of H2O2 and Fe2+ (50/20mgL−1) the disinfection efficiency was independent of the addition of resorcinol because an excess of radicals were generated, and (ii) by the photo-Fenton results obtained when the concentration of resorcinol was increased from 20, 30 till 40mgL−1.

Abstract 2274: Effect of myeloperoxidase inhibitor resorcinol on colon tumorigenesis in APCmin/+ mice

Abstract Beneficial actions of non-steroidal anti-inflammatory drugs (NSAIDs) on colorectal cancer progression are well accepted. Nevertheless, NSAIDs have had only a minor impact in primary or secondary prevention - even in high risk populations - for at least two reasons. First, NSAIDs are contra-indicated in some high risk conditions, such as colitis-associated colorectal cancer, because of their corrosive actions in the gut. Second, publicity about the cardiovascular safety of NSAIDs has thwarted their potential in primary or secondary prevention of sporadic polyps. Thus, we sought to identify molecular targets and agents that might work in these situations. Myeloperoxidase (MPOx) from neutrophils is distantly related to the cyclooxygenase (COX) enzymes. MPOx and its relative, eosinophil peroxidase (EPOx) constitute part of the innate immune process in the normal gut, and the pathology of colitis. Hypochlorite generated by MPOx oxidizes amino acids (serine, threonine) and polyunsaturated fatty acids (arachidonic acid). Several of these oxidative by-products generated by MPOx - hypochlorite are non-prostaglandin E2 (PGE2) mediators that enhance β-catenin signaling. Thus, we hypothesized that MPOx and its by-products may promote intestinal malignancy, comparable to the actions of COX and PGE2. Using APCmin/+ mice we tested the effect of resorcinol, an irreversible MPOx inhibitor, under two experimental conditions: 1) colorectal and intestinal tumor promotion accompanying inflammation induced with dextran sodium sulfate (DSS); and 2) tumor formation in the normal intestine, without colitis, but with basal “inflammation” (para-inflamation) due to commensal bacteria in the gut. For APCmin/+ mice with DSS induced inflammation, 1.25mg/kg intraperitoneal (IP) resorcinol caused a 30% reduction in colorectal adenoma numbers, and a 40% reduction in average adenoma size (p&amp;lt;0.05). Small intestinal polyp numbers were also reduced by 20%. Surprisingly, in APCmin/+ mice without DSS-induced colitis, but with basal “inflammation” of the normal gut, resorcinol 1.25mg/kg IP caused a modest, but detectable increase in adenoma formation. To reconcile these results we hypothesize that anti-inflammatory effects dominate the high intensity inflammation in the DSS colitis-APCmin/+ mouse, and manifest as reduced colitis-associated tumor formation. Conversely, we hypothesize that anti-inflammatory action in the lesser basal “inflammation” of normal APCmin/+ mice suppresses innate immune surveillance and elimination processes, which spares aberrant crypt foci. Alternatively, oxidation of resorcinol in the gut of normal APCmin/+ mice may be generating tumor promoting quinine metabolites. We are breeding an MPOx null-APCmin/+ mouse to help distinguish between these two alternatives. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2274.

A New Inhibition Kinetic Spectrophotometric Method for the Determination of Resorcinol

A new, simple, inexpensive and fast kinetic spectrophotometric method was developed for the determination of trace amounts of resorcinol over the range of 0.02‐0.80 μg/mL. The method is based on the inhibitory effect of resorcinol on the formaldehyde catalyzed oxidation reaction of of cresyl violet by bromate in acidic media is reported. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of cresyl violet at 596 nm with a fixed‐time 0.5–2.5 min from initiation of the reaction.The detection limit is 0.017 μg/mL and relative standard deviation of 0.1 and 0.5 μg/mL resorcinol for six replicate measurements was 2.6 and 2.9 %, respectively. The method was applied to the determination of resorcinol in water samples.

EFFECT OF VISCOSE SHORT FIBERS REINFORCEMENT ON THE PHYSICO-MECHANICAL PROPERTIES OF NATURAL RUBBER VULCANIZATES

The properties of natural rubber (NR) vulcanizates loaded with viscose short fibers were studied using different adhesion systems. It was found that the two systems, HRH (hydrated silica, resorcinol and hexamethylene tetramine) and one of (hydrated silica, m-phenylenediamine and hexamethylene tetramine) were the most effective. The synergistic effect of resorcinol and m-phenylenediamine was also studied. The effect of fiber loading on the mechanical properties of the vulcanizates was also investigated.

Involvement of glucokinase translocation in the mechanism by which resorcinol inhibits glycolysis in hepatocytes

Proglycosyn and resorcinol stimulate glycogen synthesis and inhibit glycolysis in hepatocytes. The former effect is attributed to inactivation of phosphorylase mediated by glucuronidated metabolites. This study investigated the mechanism by which resorcinol inhibits glycolysis. Resorcinol (150 microM) inhibited glycolysis in hepatocytes incubated with glucose (15-35 mM) but not with dihydroxyacetone (10 mM). The inhibition of glycolysis at elevated glucose concentration was associated with inhibition of glucose-induced dissociation of glucokinase and aldolase. The resorcinol concentration that caused half-maximal inhibition (20-43 microM) increased with increasing glucose concentration (15-35 mM). Resorcinol inhibited the translocation of glucokinase and the stimulation of detritiation of [2-3H]glucose and [3-3H]glucose caused by sorbitol (10-200 microM), but it potentiated the stimulation of glycogen synthesis. The inhibition of glycolysis by resorcinol could not be accounted for by diversion of substrate to glycogen. The glucose 6-phosphate content correlated with the free glucokinase activity. Resorcinol counteracted the increase in glucose 6-phosphate and fructose 2,6-bisphosphate caused by elevated glucose concentration or by sorbitol. The suppression of glucose 6-phosphate at high glucose concentration (15-35 mM) could be explained by the low activity of free glucokinase. However, the suppression at 5 mM glucose was due in part to an independent mechanism. The effect of resorcinol on glucokinase translocation was partly counteracted by galactosamine, which suppresses UDP-glucose and inhibits glucuronide formation, and was mimicked by phenol and p-nitrophenol but not by p-nitrophenylglucuronide. It is concluded that resorcinol inhibits glycolysis at elevated glucose concentration or when stimulated by sorbitol through increased glucokinase binding. The results indicate a link between glucuronidation and glucokinase translocation.

Involvement of phosphorylase kinase inhibition in the effect of resorcinol and proglycosyn on glycogen metabolism in the liver.

The purpose of this study was to identify the mechanism by which proglycosyn and resorcinol decrease the phosphorylase a content and the fructose 2,6-bisphosphate concentration in isolated hepatocytes. The intracellular concentrations of the glucuronide derivatives of proglycosyn and resorcinol have been measured by HPLC in hepatocytes incubated for 5 min or 30 min with different concentrations of these agents. At both times, there was a reciprocal relationship between the phosphorylase a content and the intracellular concentration of the glucuronidated metabolites, half-maximal inactivation being observed at about 2 mumol/g protein and 0.25 mumol/g protein for resorcinylglucuronide and proglycosyn-glucuronide, respectively. Glycogen synthase was not significantly activated by these agents after 5 min but was well activated after 30 min. Preincubation of hepatocytes with 1 mM resorcinol or with 100 microM proglycosyn resulted in a decrease in the rate at which phosphorylase was activated following the addition of glucagon, vasopressin, the protein phosphatase inhibitor calyculin A or the calcium ionophore A 23187, but did not reduce the rate of synthase inactivation. Proglycosynglucuronide and resorcinylglucuronide inhibited phosphorylase kinase in liver Sephadex filtrates, with Ki values of about 0.75 mM and 4 mM, respectively. Preincubation of the filtrates with ATP and cAMP decreased the sensitivity of phosphorylase kinase to resorcinylglucuronide by about fourfold. It is concluded that the effect of resorcinol and proglycosyn on the phosphorylase a content is due, at least partly, to an inhibition of phosphorylase kinase by their glucuronidated metabolites. Resorcinol and proglycosyn caused a parallel decrease in the concentration of fructose 2,6-bisphosphate and of hexose 6-phosphates, without significantly changing the activity of 6-phosphofructo-2-kinase. The decrease in the fructose 2,6-bisphosphate concentration appears therefore to be secondary to the decrease in the hexose 6-phosphate concentration.