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41.
N-n-octylaniline in xylene is used for the extractive separation of gold(III) from halide media. Gold(III) was extracted quantitatively with 10 ml of 2% reagent in xylene from 0.5-10 M and 0.5-8 M hydrochloric acid and hydrobromic acid, respectively. It was stripped from the organic phase with ammonia buffer solution (pH 10.1) and estimated spectrophotometrically with stannous chloride. The effect of metal ion, acids, reagent concentration and of various foreign ions has been investigated. Method is applicable to the analysis of synthetic mixtures containing platinum metals and alloy samples. The method is fast, accurate and precise. 相似文献
42.
43.
Titanium dioxide nanoparticles were prepared by a electrochemical reduction method using parameters such as current density, solvent polarity, distance between electrodes, and concentration of stabilizers to control the size of the nanoparticles. The nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and their catalytic performance was tested for the synthesis of a series of 4-aryldiene-2-phenyl-5(4)-oxazolones from the cyclodehydration and condensation of the respective aldehyde, hippuric acid and acetic anhydride. Easy availability, reusability and eco-friendliness were some prominent features of the nanocrystalline titanium dioxide catalyst. 相似文献
44.
Priyanka Anandgaonker Ganesh Kulkarni Suresh Gaikwad Anjali Rajbhoj 《Arabian Journal of Chemistry》2019,12(8):1815-1822
Titanium dioxide nanoparticles were successfully prepared by electrochemical method. The tetra propyl ammonium bromide salt was used as stabilizing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio by optimizing current density. The parameters such as current density, solvent polarity, distance between electrodes and concentration of stabilizers were used to control the size of nanoparticles. The synthesized titanium dioxide nanoparticles were characterized by using UV–Visible spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy dispersive spectrophotometer (EDS) and transmission electron microscopy (TEM) analysis techniques. TEM analysis proved a nearly tetragonal structure with size of 25–30 nm which was in agreement with the result calculated from the XRD analysis. EDS analysis revealed the presence of Ti and O element. The nanoparticles were screened for their in vitro antibacterial activity against human pathogens such as gram negative Escherichia coli (E. coli), and gram positive Staphylococcus aureus strains and which proved excellent results. 相似文献
45.
Nitin D. Gaikwad Sachin V. Patil Vivek D. Bobade 《Journal of heterocyclic chemistry》2013,50(3):519-527
A series of new 1‐[4‐(2,3,4‐substituted‐phenyl) thiazol‐2‐yl]‐3‐(2,3,4‐substituted‐phenyl)‐1H‐pyrazole‐4‐carbaldehyde ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m ), 4‐[4‐(4‐substituted‐phenyl) thiazol‐2‐yl]‐3‐(4‐substituted‐phenyl)‐1‐phenyl‐1H‐pyrazole ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i ), 4‐[4‐(4‐substituted phenyl)thiazol‐2‐yl]‐1‐phenyl‐1H‐pyrazol‐3‐amine ( 10a , 10b , 10c , 10d , 10e , 10f , 10g ) have been synthesized by using Vilsmeier Haack formylation and Hantzsch reaction in high yield. All the synthesized compounds were tested qualitative (Zone of inhibition) and quantitative antimicrobial activities (MIC). Most of the synthesized compounds showed potent antimicrobial activity against gram positive and gram negative bacteria as well as fungi species. 相似文献
46.
Dipake Sudarshan S. Lande Machhindra K. Rajbhoj Anjali S. Gaikwad Suresh T. 《Research on Chemical Intermediates》2021,47(6):2245-2261
Research on Chemical Intermediates - Zeolite ZSM-11 catalyst was prepared by hydrothermal method and characterized by FTIR, XRD, SEM, HRTEM, EDS, and BET analysis techniques. The catalyst shows... 相似文献
47.
Holothuria scabra produces a monomeric lectin (HSL) of 182 kDa. HSL showed strong antibacterial activity and induced bacterial agglutination under in vitro conditions, indicating its role in animals’ innate immune responses. Very few lectins have been reported from echinoderms and none of these lectins have been explored in detail for their sugar-binding kinetics. Affinity, kinetics and thermodynamic analysis of glycans and glycoproteins binding to HSL were studied by fluorescence and surface plasmon resonance spectroscopy. Lectin binds with higher affinity to O-linked than N-linked asialo glycans, and the affinities were relatively higher than that for sialated glycans and glycoproteins. T-antigen α-methyl glycoside was the most potent ligand having the highest affinity (Ka 8.32 ×107 M?1). Thermodynamic and kinetic analysis indicated that the binding of galactosyl Tn-antigen and asialo glycans is accompanied by an enthalpic contribution in addition to higher association rate coupled by low activation energy for the association process. Presence of sialic acid or protein matrix inhibits binding. Higher affinity of HSL for O-glycans than N-glycans had biological implications; since HSL specifically recognizes bacteria, which have mucin or O-glycan cognate on their cell surfaces and play a major role in animal innate immunity. Since, HSL had higher affinity to T-antigen, makes it a useful tool for cancer diagnostic purpose. 相似文献
48.
(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method. 相似文献
49.
Borhade N Pathan AR Halder S Karwa M Dhiman M Pamidiboina V Gund M Deshattiwar JJ Mali SV Deshmukh NJ Senthilkumar SP Gaikwad P Tipparam SG Mudgal J Dutta MC Burhan AU Thakre G Sharma A Deshpande S Desai DC Dubash NP Jain AK Sharma S Nemmani KV Satyam A 《Chemical & pharmaceutical bulletin》2012,60(4):465-481
In continuation of our efforts to discover novel nitric oxide-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) as potentially "Safe NSAIDs," we report herein the design, synthesis and evaluation of 21 new NO-NSAIDs of commonly used NSAIDs such as aspirin, diclofenac, naproxen, flurbiprofen, ketoprofen, sulindac, ibuprofen and indomethacin. These prodrugs have NO-releasing disulfide linker attached to a parent NSAID via linkages such as an ester (compounds 9-16), a double ester (compounds 17-24), an imide (compounds 25-30) or an amide (compounds 31-33). Among these NO-NSAIDs, the ester-containing NO-aspirin (9), NO-diclofenac (10), NO-naproxen (11), and the imide-containing NO-aspirin (25), NO-flurbiprofen (27) and NO-ketoprofen (28) have shown promising oral absorption, anti-inflammatory activity and NO-releasing property, and also protected rats from NSAID-induced gastric damage. NO-aspirin compound 25, on further co-evaluation with aspirin at equimolar doses, exhibited comparable dose-dependent pharmacokinetics, inhibition of gastric mucosal prostaglandin E(2) (PGE(2)) synthesis and analgesic properties to those of aspirin, but retained its gastric-sparing properties even after doubling its oral dose. These promising NO-NSAIDs could therefore represent a new class of potentially "Safe NSAIDs" for the treatment of arthritic pain and inflammation. 相似文献
50.
Sreejith RK Suresh CG Bhosale SH Bhavnani V Kumar A Gaikwad SM Pal JK 《Journal of fluorescence》2012,22(1):431-441
In mammalian cells, the heme-regulated inhibitor (HRI) plays a critical role in the regulation of protein synthesis at the
initiation step through phosphorylation of α-subunit of the eukaryotic initiation factor 2 (eIF2). In this study we have cloned
and performed biophysical characterization of the kinase catalytic domain (KD) of rabbit HRI. The KD described here comprises
kinase 1, the kinase insertion domain (KI) and kinase 2. We report here the existence of an active and stable monomer of HRI
(KD). The HRI (KD) containing three tryptophan residues was examined for its conformational transitions occurring under various
denaturing conditions using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic
dye binding. The parameter A and phase diagram analysis revealed multi-state unfolding and existence of three stable intermediates
during guanidine hydrochloride (Gdn-HCl) induced unfolding of HRI (KD). The protein treated with 6 M Gdn-HCl showed collisional
and static mechanism of acrylamide quenching and the constants (K
sv
= 3.08 M−1and K
s
= 5.62 M−1) were resolved using time resolved fluorescence titration. Based on pH, guanidine hydrochloride and temperature mediated
transitions, HRI (KD) appears to exemplify a rigid molten globule-like intermediate with compact secondary structure, altered
tertiary structure and exposed hydrophobic patches at pH 3.0. The results indicate the inherent structural stability of HRI
(KD), a member of the class of stress response proteins. 相似文献