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51.
In this research work a sulfonamide from tranexamic acid has been synthesized followed by its metal complexation. p‐Bromo benzene sulfonyl chloride was used to synthesize sulfonamide using eco‐friendly atmosphere. The sulfonamide prepared from tranexamic acid has been utilized for the preparation of metal complexes with various metals like Ni, Cu, Co, Mn, Pb, Cd, Cr, Fe, Sn, and Sr. All synthesized compounds were characterized by applying different spectral techniques such as Fourier‐transform infrared (FTIR), mass spectrometry, and X‐ray diffraction (XRD) analysis. The biological activities such as radical scavenging activity, enzyme inhibition, antifungal, antibacterial, and anticancer were performed. It was concluded from the results that compounds showed moderate to good activity. Cu complex of sulfonamide showed the highest antioxidant potential (87.69 ± 1.8% with IC50 137 ± 1.0 μg) while Cr complex depicted the highest activity against both enzymes; AChE (73.51 ± 1.7% with IC50 165 ± 1.1 μg) and BChE (70.05 ± 1.3% with IC50 152 ± 1.8 μg). Mn complex showed good results against six bacterial strains comparable with standard drug. Cr complex depicted highest anticancer activity against MCF7 and human corneal epithelial cell (HCEC) cell lines 45.73% and 25.40%, respectively. These results concluded that metal complexes of sulfonamide may be good induction in the future for medical purposes.  相似文献   
52.
Research on Chemical Intermediates - The remarkable rise in industrial utilization of volatile organic compounds has increased their presence in environmental matrices, which is a menace for human...  相似文献   
53.
Amylase (EC 3.2.1.1) enzyme has gained tremendous demand in various industries, including wastewater treatment, bioremediation and nano-biotechnology. This compels the availability of enzyme in greater yields that can be achieved by employing potential amylase-producing cultures and statistical optimization. The use of Plackett–Burman design (PBD) that evaluates various medium components and having two-level factorial designs help to determine the factor and its level to increase the yield of product. In the present work, we are reporting the screening of amylase-producing marine bacterial strain identified as Bacillus sp. H7 by 16S rRNA. The use of two-stage statistical optimization, i.e., PBD and response surface methodology (RSM), using central composite design (CCD) further improved the production of amylase. A 1.31-fold increase in amylase production was evident using a 5.0 L laboratory-scale bioreactor. Statistical optimization gives the exact idea of variables that influence the production of enzymes, and hence, the statistical approach offers the best way to optimize the bioprocess. The high catalytic efficiency (kcat/Km) of amylase from Bacillus sp. H7 on soluble starch was estimated to be 13.73 mL/s/mg.  相似文献   
54.
A novel efficient protocol for the synthesis of 5-imino-1,2,4-thiadiazole motif in open air and visible light has been reported. The reaction involves Eosin Y as photocatalyst which is a cost-effective organic dye. The designed protocol represents a novel, mild, metal free, green strategy for the construction of 1,2,4-thiadiazole nucleus by intramolecular cyclization via N─S bond formation. The reaction has been carried out under visible light exposure in ethanol: water (4:1) mixture using 2-aminopyridine and isocyanate as reactants.  相似文献   
55.
联苯胺分光光度法测定食盐中碘含量   总被引:2,自引:0,他引:2  
基于在盐酸介质中,碘酸钾氧化联苯胺使其显色,提出了光度法测定食盐中微量碘的方法。在40℃的水浴中,当2 mol.L-1盐酸溶液用量为1.00 mL0、.42 g.L-1联苯胺溶液用量为0.80 mL时,方法的线性范围为100~1 400μg.L-1,最大吸收波长在425 nm处,表观摩尔吸光率为1.4×105L.mol-1.cm-1。用于测定加碘食盐中碘含量的测定,回收率在97.5%~101.2%之间,相对标准偏差(n=7)在0.9%~1.9%之间。  相似文献   
56.
The role of reactive oxygen species (ROSs) and effect of solution matrix have been investigated for the degradation of trichloroethylene (TCE). Zeolite-supported nano iron (Z-nZVI) was synthesized as an activator to catalyze sodium percarbonate (SPC) with or without hydroxylamine, i.e. as reducing agent (RA). The probe tests confirmed the generation of OH· and O 2 in the Z-nZVI activated SPC system in absence of the RA, while the presence of RA significantly increased the generation of OH· and O 2 radicals. Scavenger tests demonstrated that OH· was the main ROS responsible for TCE degradation, whereas O 2 also participated in TCE degradation. From the solution matrix perspective, the experimental results confirmed significant scavenging effects of Cl? (1.0, 10.0, and 100 mmol L?1) and HCO3 ? (1.0 and 10.0 mmol L?1), whereas the scavenging effects were fairly impeded at 100 mmol L?1 concentration of HCO3 ?. On the other hand, a considerable decline in scavenging effect was observed in the presence of RA in tested Cl? and HCO3 ? concentration ranges. In addition, negligible scavenging effects of NO3 ? and SO4 2? anions were found in all tested concentrations. The effect of initial solution pH on catalytic activity indicated a significant increase in the TCE degradation in the presence of RA even at higher pH value of 9. The results indicated that the Z-nZVI activated SPC system in presence of RA can effectively degrade chlorinated organic solvents, but it is important to consider the intensive existence of anions in groundwater.  相似文献   
57.
Summary This paper describes a new computer-enhanced dual-channel SQUID susceptometer designed to achieve accuratein vivo estimates of tissue storage iron concentrations. We discuss the practical design considerations, instrumental noise performance and anticipated clinical resolution of the new system. Work supported by NIH grants HL24198 and AM25105.  相似文献   
58.
A simple gas chromatographic--mass spectrometric method capable of measuring estrone, estradiol, and estriol simultaneously with a sensitivity close to that of radioimmunoassay has been developed. The estrogens in serum were extracted with diethyl ether, and internal standards (3-O-C2H3-estrone, 3-O-C2H3-estradiol, and 3-O-C2H3-estriol) were added, followed by converting to methyl ether compounds with an extractive alkylation procedure. The methyl ethers were then acetylated. Analyses were performed using a SP-2250 capillary column gas chromatograph coupled with an electron-impact mass spectrometer. The estrogen methyl ether acetate derivatives were more stable chemically and gave less fragmentation upon electron impact than the conventional trimethylsilyl derivatives. The use of selected ion monitoring of molecular ions and that of the corresponding internal standards (M + 3) provides a sensitivity down to 10 pg for estrone and estradiol and to 200 pg for estriol. The time required for the preparation of multiple samples is within 4 hours.  相似文献   
59.
In the present work, a general case of gas absorption with first order irreversible chemical reaction in a liquid film, for laminar flow over a solid wall, has been analyzed theoretically. First order chemical reaction between the diffused solute and the wall is also considered. Laplace transform followed by power series method has been applied to solve the governing equations. Thereafter, the obtained analytical solution of the developed general model has been successfully verified by an explicit numerical scheme. The general model has also been reduced to six simplified cases, tackled by previous workers and an excellent agreement in the solutions is observed. Moreover, the results are validated by the experimental data available in the literature. The obtained concentration profiles in both the phases have been used to find the absorption rates and enhancement factor.  相似文献   
60.
Cyclooxygenases-1 and -2 are tyrosyl radical (Y·)-utilizing hemoproteins responsible for the biosynthesis of lipid-derived autocoids. COX-2, in particular, is a primary mediator of inflammation and believed to be up-regulated in many forms of cancer. Described here are first-of-a-kind studies of COX-2-catalyzed oxidation of the substrate analogue linoleic acid. Very large (≥20) temperature-independent deuterium kinetic isotope effects (KIEs) on the rate constant for enzyme turnover were observed, due to hydrogen atom abstraction from the bisallylic C-H(D) of the fatty acid. The magnitude of the KIE depends on the O(2) concentration, consistent with reversible H/D tunneling mediated by the catalytic Y·. At physiological levels of O(2), retention of the hydrogen initially abstracted by the catalytic tyrosine results in strongly temperature-dependent KIEs on O-H(D) homolysis, also characteristic of nuclear tunneling.  相似文献   
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