Binding interaction of laccases from Bacillus Subtilis after industrial dyes exposure: Molecular docking and molecular dynamics simulation studies

Dyes are becoming more widely used around the world wide, but there is no effective bioremediation approach for removing them completely from the environment. Several dyes are mentioned to be degraded through bacteria; however, it's still unknown how the particular enzymes act throughout the dye degradation. The behavior and function of these enzymes in the biodegradation of azo dyes (Textile dyes) had been investigated experimentally by the numbers of the researchers, however, the molecular mechanisms remain unclear. Therefore, the interaction mechanisms of textile dye (methyl orange) with laccase from B. subtilis were explored through molecular docking and molecular dynamics simulations, the three selected dyes (methyl orange, malachite green, and acid blue 62) that interact positively with laccase on the basis of their maximum binding energy, molecular docking results indicate that one of the three dyes is more stable as a target for degradation through Bacillus subtilis laccase. Therefore, subsequent research focused solely on one substrate: methyl orange. Molecular Dynamics simulation study was applied after the molecular docking to determine the interaction between laccases and methyl orange dyes. The trajectory was proved with root mean square deviation and root mean square fluctuation analysis. According to the molecular dynamics simulation results, laccase-methyl orange complexes remain stable during the catalytic reaction. So, this study demonstrates how laccase is involved in methyl orange bioremediation.

Novel Selective Spectrophotometric Methods For The Determination Of Methimazole In Pure Form And In Pharmaceutical Formulation

Objective: To develop and validate new, selective spectrophotometric colorimetric analytical methods for the quantification of methimazole in its pure form and in its pharmaceutical preparations. Methods: Method A is based on the oxidation of methimazole with potassium permanganate in alkaline medium, the manganate ion produced was measured at λmax= 610 nm. Method B is a kinetic determination of methimazole using fixed-time method based on the oxidation of methimazole using known excess of cerium (IV) nitrate in acidic medium and assessing the unreacted Ce (IV) by adding a fixed amount of methyl orange and measuring the absorbance of the resultant solution at λmax=507 nm which is equivalent to the unreacted methyl orange. The reaction conditions and analytical parameters are investigated and optimized. Method validation was carried out according to ICH guidelines in terms of linearity, LOD, LOQ, precision, and accuracy. Results: Beer’s law is obeyed in the range of 1.50–15.00 μg/ml for method A and 0.25–3.00 μg/ml for method B. The developed methods were subjected to the detailed validation procedure. The proposed spectrophotometric methods were applied for the determination of the methimazole in its pure form and in its pharmaceutical formulation. The percentage recoveries were found to be 100.82 % and 99.85 % in the pharmaceutical formulation for the two proposed methods, respectively. Conclusion: Both developed spectrophotometric methods, considered as green analytical chemistry, were found to be novel, highly selective and can be applied for the quality control of methimazole in its pure form and in its pharmaceutical formulation based on the simplicity, applicability of the parameters, accessibility of the reagents employed and reasonably low time of analysis.

Investigation of Some Parameters Affecting Methyl OrangeRemoval by Fusarium acuminatum

ABSTRACT Dye stuff released to the ecosystem from textile industries cause a serious contamination and become a major environmental problem over the last few decades. As biological decolorization of textile wastewater is an important issue, Fusarium . acuminatum was used to removal of a frequently used textile dye, methyl orange. Live pellet of Fusarium acuminatum was used and decolorization studies performed in various temperatures and pH conditions with different dye concentrations. The highest decolorization rate was observed at 35ᴼC. 60 mg/L was found as the optimum initial dye concentration. In the pH range of 3-4, decolorization rate was approximately 70%. It was seen that Fusarium acuminatum have the great ability of the methyl orange removal. To our knowledge, it took place for the first time in the literature.

A new spectrophotometric method for the determination of fluvoxamine maleate in pure form and in pharmaceutical formulation.

A simple, accurate and highly sensitive spectrophotometric methods are proposed for the rapid and accurate determination of fluvoxamine maleate (FXA) using bromocressol green (BCG), methyl orange (MO) and bromothymol blue (BTB). The developed methods involve formation of stable yellow colored chloroform extractable ion-associate complexes of the amino derivative (basic nitrogen) of the FXA with three sulphonphthalein acid dyes, namely; BCG, MO and BTB, in potassium hydrogen phthalate buffer pH 3.3, 3.6 and 3.4 respectively. The ion-associates exhibit absorption maxima at 420, 420 and 410 nm for BCG, MO and BTB, respectively. FXA can be determined up to 2.0–16, 2.0–15 and 2.0–20 μgmL−1 for BCG, MO and BTB, respectively. The effect of optimum conditions via pH on the ion pair formation, reagent concentration, time and temperature, and solvent was studied. The composition of the ion pairs was found 1:1 by Job’s method. The low relative standard deviation values indicate good precision and high recovery values. These methods have been successfully applied for the assay of FXA in pure form and in pharmaceutical formulations and the results are in good agreement with those obtained by the official method.

Natural Indicator as a substitute to Synthetic indicator-A Developmental Approach.

Synthetic indicators had perpetually been an alternative choice for all types of titration since long time. However price had always been a tangle. Therefore development of an indicator from natural source i.e. from the flower extracts had been the main aim of this present research work. The current work complies data regarding the comparison of Natural indicator and synthetic indicator and whether or not it may be substituted from Synthetic indicator.

A New Extractive Spectrophotometric Method for the Estimation of Alosetron.

Two simple, accurate, rapid and sensitive Methods (A and B) have been developed for the estimation of Alosetron in its pharmaceutical dosage form. The Method A is based on the formation yellow colored chromogen, due to reaction of Alosetron Hydrochloride with Metanil yellow dye, formation of ion association complexes of the drug with dyes in phosphate buffer of pH 3.6 followed by their extraction in chloroform which exhibits λmax at 410 nm. The Method B is based on the formation of light yellow colored chromogen due to reaction of Alosetron Hydrochloride with Methyl Orange dye, formation of ion association complexes of the drug with dyes in phosphate buffer of pH 3.6 followed by their extraction in chloroform, which exhibits λ max at 422 nm. The absorbance-concentration plot is linear over the range of 5-60 mcg/mL for Method A and 50-120 mcg/mL for Method B. Results of analysis for all the methods were validated statistically and by recovery studies. The proposed methods are precise, accurate, economical and sensitive for the estimation of Alosetron in bulk drug and in its Tablet dosage form.

Adsorption potentialites of bio-sorbents derived from prosopis cineraria and hibiscus rosa-sinensis in the removal of methyl orange dye from polluted waters.

Leaves, stems and their ashes of Prosopis cineraria and Hibiscus rosa-sinensis have been explored for their surface sorption abilities towards Methyl Orange Dye using simulated waters. Various physicochemical parameters such as pH, time of equilibration and sorbent concentrations are optimized for evoking the sorption potentialities of the plant materials for the maximum extraction of the Methyl Orange Dye from waters. The surface sorption nature is found to pH sensitive and % of removal is maximum near pH: 3. % removal of the Dye is more with ashes than respective bio-materials. Co-anions, in fivefold excess, are found to be interfering in the order: trivalent anion>divalent > monovalent while co-cations have shown relatively less interference on the extraction of the Dye at optimum conditions of extraction. The adoptability of the methodologies developed is tested with some real industrial effluents.

Extractive colorimetric method development and validation for erlotinib in bulk and tablet dosage form.

Two simple, rapid, sensitive, precise and economic spectrophotometric methods have been developed for the estimation of Erlotinib in bulk and tablet formulation. During the course of study, it was observed that solution of the drug formed colored ion-pair complexes with Bromocresol Green (BCG) and Methyl Orange (MO) in phosphate buffer pH 2.5, and extracted in chloroform. This property of the drug was followed for the development of colorimetric methods for analysis of drug. The complex of etoricoxib with BCG and MO showed λ max at 418.5 nm and 424.4 nm respectively. The complex was stable up to 22 hrs and obeyed Beer's law over the concentration ranges of 10-1000 μg/ml. Correlation coefficient was found to be 0.9985. In addition we have determined the molar absorptivity, Sandell sensitivity and the optimum conditions for quantitative analysis of erlotinib. These methods were validated statistically. Recovery studies gave satisfactory results indicating that none of common additives and excipients interfere the assay method. The proposed methods are found to be simple, accurate and reproducible that was successfully applied for the analysis of tablet formulation.