Activity of Candida rugosa lipase immobilized on gamma-Fe2O3 magnetic nanoparticles

We report the stability and enzymatic activity of Candida rugosa Lipase (E.C.3.1.1.3) immobilized on gamma-Fe2O3 magnetic nanoparticles. The immobilization strategies were either reacting the enzyme amine group with a nanoparticle surface acetyl, or amine groups. In the former, the enzyme was attached through a C=N bond, while in the latter it was connected using glutaraldehyde. AFM images show an average particle size of 20 +/- 10 nm after deconvolution. The enzymatic activity of the immobilized lipase was determined by following the ester cleavage of p-nitrophenol butyrate. The covalently immobilized enzyme was stabile and reactive over 30 days.     

Microwave-assisted synthesis of triazole derivatives conjugated with piperidine as new anti-enzymatic agents

The current study was aimed for the study of piperidine-based triazole compounds for their biological potential against various enzymes. A novel library of compounds, 9a-r , having piperidine, 1,2,4-triazole, and propanamides was synthesized through consecutive steps including the formation of sulfonamide, hydrazide, 1,2,4-triazole, and thio-ether. Initially, 4-methoxybenzenesulfonyl chloride ( 1 ) and ethyl isonipecotate ( 2 ) were utilized to develop ethyl 1-(4-methoxyphenylsulfonyl)-4-piperidinecarboxylate ( 3 ). The product 3 was converted into respective hydrazide ( 4 ) which was further cyclized into 1,2,4-triazole ( 5 ) nucleus. A series of propanamides, 8a-r , were synthesized from different amines, 6a-r . These electrophiles, 8a-r , were reacted with compound 5 under conventional and microwave-assisted protocols to acquire the library of hybrids, 9a-r . The structural confirmations were availed by ¹H-NMR, ¹³C-NMR, and IR techniques. The whole series was evaluated for biological potential against acetylcholinesterase (AChE) and α-glucosidase enzymes. The biological evaluation ranges low to high in potential for different compounds based on the structural variations of synthesized compounds. Almost all the compounds remained active against both the enzymes except a few ones. The bovine serum albumin (BSA) binding study demonstrated the flow of drug in the body, and the docking study explained the interactions responsible for active behavior of synthesized compounds.     

Topotactic oxidation pathway of ScTiO3 and high-temperature structure evolution of ScTiO3.5 and Sc4Ti3O12-type phases

The novel oxide defect fluorite phase ScTiO(3.5) is formed during the topotactic oxidation of ScTiO(3) bixbyite. We report the oxidation pathway of ScTiO(3) and structure evolution of ScTiO(3.5), Sc(4)Ti(3)O(12), and related scandium-deficient phases as well as high-temperature phase transitions between room temperature and 1300 °Cusing in-situ X-ray diffraction. We provide the first detailed powder neutron diffraction study for ScTiO(3). ScTiO(3) crystallizes in the cubic bixbyite structure in space group Ia3 (206) with a = 9.7099(4) ?. The topotactic oxidation product ScTiO(3.5) crystallizes in an oxide defect fluorite structure in space group Fm3m (225) with a = 4.89199(5) ?. Thermogravimetric and differential thermal analysis experiments combined with in-situ X-ray powder diffraction studies illustrate a complex sequence of a topotactic oxidation pathway, phase segregation, and ion ordering at high temperatures. The optimized bulk synthesis for phase pure ScTiO(3.5) is presented. In contrast to the vanadium-based defect fluorite phases AVO(3.5+x) (A = Sc, In) the novel titanium analogue ScTiO(3.5) is stable over a wide temperature range. Above 950 °C ScTiO(3.5) undergoes decomposition with the final products being Sc(4)Ti(3)O(12) and TiO(2). Simultaneous Rietveld refinements against powder X-ray and neutron diffraction data showed that Sc(4)Ti(3)O(12) also exists in the defect fluorite structure in space group Fm3m (225) with a = 4.90077(4) ?. Sc(4)Ti(3)O(12) undergoes partial reduction in CO/Ar atmosphere to form Sc(4)Ti(3)O(11.69(2)).     

Synthesis of Triazole and Isoxazole Based Novel Unsymmetrical Bis‐heterocycles

Novel unsymmetrical bis‐heterocyclic compounds encompassing triazole and isoxazole moieties were synthesized by employing 1,3‐dipolar cycloaddition/click chemistry approach using 5‐butynyl‐1,2,3‐triazoles and 5‐butynyl isoxazoles.     

Plasma activated water: the next generation eco-friendly stimulant for enhancing plant seed germination,vigor and increased enzyme activity,a study on black gram (Vigna mungo L.)

Plasma Chemistry and Plasma Processing - Chemical fertilization in agriculture is threatening to the ecosystem. Therefore, the use of eco-friendly stimulant for crop revolution is highly desirable....     

A simple model for a two-stage chemical reaction with diffusion

We analyse the evolution of a two-stage chemical reaction betweentwo neighbouring plumes of reactants. Under the assumption thatthe plumes are approximately Gaussian we derive a system ofordinary differential equations for the total amount, the centroidand the variance of each reactant. We compare the solution ofthese equations with full numerical simulation of the reaction.Excellent agreement is obtained, with solution of the near-Gaussianmodel requiring considerably less computational effort thanthe full simulations. Of key importance is the yield of thereaction, and we discuss this feature in particular.     

Determination of Rosuvastatin Calcium in its Bulk Drug and Pharmaceutical Preparations by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A normal-phase TLC method has been established for the estimation of rosuvastatin calcium in its bulk drug and pharmaceutical...     

Development and validation of new assay method for the simultaneous analysis of diltiazem, metformin, pioglitazone and rosiglitazone by RP-HPLC and its applications in pharmaceuticals and human serum

Simple, sensitive, rapid, and accurate high-performance liquid chromatographic (HPLC) method is developed and validated for the simultaneous determination of diltiazem, metformin, pioglitazone, and rosiglitazone hydrochloride in raw materials, their pharmaceutical formulations, and human serum. In HPLC, all the above drugs were chromatographed using acetonitrile-methanol-water (30:20:50, v/v, pH 2.59 ± 0.02) as the mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The separation is carried out on a Hiber, 250-4.6 RP-18 column, equipped with a UV-vis detector at 230 nm. All the antidiabetic drugs eluted at different retention time and each showed a good resolution from diltiazem. The method is successfully applied to pharmaceutical formulations because no chromatographic interferences from the tablet excipients are found. The method is found to be linear, accurate, and precise with apposite detection and quantification limit. Suitability of the method for the quantitative determination of the drugs is proven by validation in accordance with the requirements laid down by International Conference on Harmonization (ICH) guidelines. The validation results, together with statistical treatment of the data, demonstrated the reliability of this method.     

E6 as a unifying gauge symmetry

Some consequences of embedding gauge models of strong, weak and electromagnetic interactions in the exceptional group E₆ are presented.