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81.
[reaction: see text] Optimized conditions for the decoration of the 2(1H)-pyrazinone scaffold were developed by applying the Chan-Lam protocol. It was demonstrated that this Cu(II)-mediated cross-coupling reaction resulted in significantly improved yields and rates when performed under microwave irradiation with simultaneous cooling at 0 degrees C, applying a mixture of bases Et(3)N/pyridine. 相似文献
82.
83.
Vishal P. Oza Pritesh P. Parmar Sushil Kumar R. B. Subramanian 《Applied biochemistry and biotechnology》2010,160(6):1833-1840
Withania somnifera L. has been traditionally used as a sedative and hypnotic. The present study was carried out for the purification, characterization,
and in vitro cytotoxicity of l-asparaginase from W. somnifera L. l-Asparaginase was purified from the fruits of W. somnifera L. up to 95% through chromatography. The purified l-asparaginase was characterized by size exclusion chromatography, polyacrylamide gel electrophoresis (PAGE), and 2D PAGE.
The antitumor and growth inhibition effect of the l-asparaginase was assessed using [3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyl-tetrazolium bromide] (MTT) colorimetric dye
reduction method. The purified enzyme is a homodimer, with a molecular mass of 72 ± 0.5 kDa, and the pI value of the enzyme was around 5.1. This is the first report of the plant containing l-asparaginase with antitumor activity. Data obtained from the MTT assay showed a LD50 value of 1.45 ± 0.05 IU/ml. W. somnifera L. proved to be an effective and a novel source of l-asparaginase. Furthermore, it shows a lot of similarity with bacterial l-asparaginases EC-2. 相似文献
84.
A methanolic extract of powdered ginger was separated on a Xterra RP 18 column using deuterium oxide as the eluent and a temperature gradient from 50 to 130 degrees C at 4 degrees C/min. On-line and off-line HPLC-NMR analysis yielded spectra for vanillin, dihydroferulic acid, zingerone and ferulic acid. The identification of dihydroferulic acid and zingerone were confirmed by mass spectroscopy. 相似文献
85.
Raunak Shubhasish Mukherjee Ashok K. Prasad Susan J.C. Schäffer Arthur C. Watterson Virinder S. Parmar 《Tetrahedron》2005,61(23):5687-5697
Regioisomeric spiro-(indoline-isoxazolidines) have been synthesized in moderate yields by the cycloaddition reaction between ethyl (3-indolylidene)acetate and various substituted α,N-diphenylnitrones, using environmentally benign microwave technology. A novel concerted reaction mechanism is described that explains the preferential formation of the regioisomeric spiro-(indoline-isoxazolidine) analogs 6 over 5. These compounds were screened for anti-mycobacterial and anti-invasive activities against tumor cells. 相似文献
86.
Suman Mehrotra J. P. Barthwal A. K. Saxena K. P. Bhargava S. S. Parmar 《Journal of heterocyclic chemistry》1981,18(6):1157-1159
Twelve 6-substituted-2-(1′-mercaptoacetyl-3′-arylurea)-3-phenyl-4-quinazolones were synthesized by condensation of 6-substituted anthranilic acids and aryl isothiocyanates followed by reaction with chloroacetyl arylurea. These compounds were characterized by their sharp melting points and elemental analyses. All compounds were evaluated for their enzyme inhibitory activity. It was found that all substituted quinazolones at a final concentration of 2 × 10?4 M inhibited in vitro monoamine oxidase and succinate dehydrogenase activity of rat brain homogenates and the degree of inhibition ranged from 11–77% and 25–53%, respectively. 相似文献
87.
J. D. Pandey Siddharth Pandey Shikha Gupta A. K. Shukla 《Journal of solution chemistry》1994,23(9):1049-1059
Viscosities of ternary liquid mixtures containing benzene + cyclohexane + carbon tetrachloride and the three possible binary combinations were measured at 25°C, and the excess viscosities were computed. Theoretical expressions for viscosity were developed on the basis of the Flory theory, the significant structure theory and a theory based on a method of estimating the properties of multi-component systems from those of binary systems. Reasonable agreement between experimental and theoretical viscosities is found. 相似文献
88.
Several 5-aryl- or 5-diphenylmethylhydracrylyl hydrazides were synthesized and converted into 5-aryl- or diphenylmethyl-2-oxazolidones. The latter compounds were further alkylated into their corresponding 5-aryl- or 5-diphenylmethyl-3-alkyl-2-oxazolidones as possible anticon-vusants. 相似文献
89.
R. C. Arora V. K. Rastogi A. K. Agrawal S. S. Parmar 《Journal of heterocyclic chemistry》1978,15(5):869-871
Some substituted 2-ethyl-3-(4-hydrazinocarbonylphenyl)-4-quinazolones and 2-ethyl-3-(4-hydrazinocarbonylmethylphenyl)-4-quinazolones were synthesized and characterized by their sharp melting points, elemental analyses and spectral data. 相似文献
90.
This paper describes the preparation of the halogeno complexes, HgX2(o-R2AsC6H4CO2H) (X = Cl, Br, I, and R = Et; X = Br, I, and R-C6H11) and the carboxylate complexes, M(o-R2-AsC6H4CO2)2nL(M = Cd, R = Et, C6H11 and n = O; M = Zn; R = Et; nL = H2O; M = Zn, R = C6H11, nL = 3H2O; M = Hg, R = p-tolyl, nL = 2H2O; M = Hg, R = Me, Ph; C6H11 and nL = EtOH). The structures already reported for the halogeno complexes with R = Ph, Me, p-tolyl and X = Cl, Br, I, have been revised on the basis of detailed scrutiny of the IR spectral data and all these complexes have been divided into four structural types out of which three retain the acid dimer unit of the free ligand. In the carboxylate complexes the lowering of νs, CO2 band and the marginal change in the νas CO2 band with respect to those of the corresponding ligand sodium salts have been attributed to the existence of a novel resonating chelating system with the possibility of having a ring current. 相似文献