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971.
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Manas ES Unwalla RJ Xu ZB Malamas MS Miller CP Harris HA Hsiao C Akopian T Hum WT Malakian K Wolfrom S Bapat A Bhat RA Stahl ML Somers WS Alvarez JC 《Journal of the American Chemical Society》2004,126(46):15106-15119
We present the structure-based optimization of a series of estrogen receptor-beta (ERbeta) selective ligands. X-ray cocrystal structures of these ligands complexed to both ERalpha and ERbeta are described. We also discuss how molecular modeling was used to take advantage of subtle differences between the two binding cavities in order to optimize selectivity for ERbeta over ERalpha. Quantum chemical calculations are utilized to gain insight into the mechanism of selectivity enhancement. Despite only two relatively conservative residue substitutions in the ligand binding pocket, the most selective compounds have greater than 100-fold selectivity for ERbeta relative to ERalpha when measured using a competitive radioligand binding assay. 相似文献
974.
The fluorescence maxima at room temperature of 5-dimethylamino-1-naphthalenesulfonamide (dansylamide) groups covalently attached to the surface of silica particles in dry form and slurried in acetonitrile exhibit varying degrees of dependence upon excitation wavelength. This dependence is attributed to the micro-heterogeneity of the surface itself and varying degrees of accessibility of the fluorophore to solvent. The observed effect may prove useful in investigations of surface environment heterogeneity at the molecular level. 相似文献
975.
S.P. McManus N. Neamati-Mazreah M.S. Paley B.A. Hovanes J.M. Harris 《Tetrahedron letters》1985,26(38):4571-4574
Comparisons of leaving group solvolytic rate ratios for mustard derivatives with other substrate types reveals unusual OTs/Cl and Cl/ODNP rate ratios for mustards. A very tight transition state is suggested. 相似文献
976.
Maria Lalia-Kantouri Monir Uddin C. C. Hadjikostas Harris Papanikolas George Palios Stergiou Anagnostis Vasiliki Anesti 《无机化学与普通化学杂志》1997,623(12):1983-1990
A series of mixed-ligand copper(II) chelates containing the anion of 2-hydroxyaryloxime(oxime) and N,N-disubstituted dithiocarbamate(dtc), [Cu(dtc)(oxime)], was prepared and characterised. The spectra (IR, ESR, electronic excitation) indicate that the CuNOS2 chromophore attains square planar geometry. The ESR observables suggest appreciable covalency. In the case of [Cu(Et2dtc)(oxime)] chelates, however, the observed data suggest distortion from square planar arrangement to a square pyramidal, indicative of a possible dimerism. In addition, the structure of the trans-bis[propanone, 1-(2-hydroxyphenyl)-oximato]copper(II), Cu(C9H10NO2)2 was determined by X-ray diffraction (monoclinic, space group P21/n, a = 12.072(7) Å, b = 5.204(2) Å, c = 13.571(6) Å, β = 103.72(1)°, Z = 2). The molecule consists of discrete Cu(ppox)2 monomeric units, where the Cu atom is in the equatorial plane bonded to two nitrogen atoms and two oxygen at distances of 1.949(2) and 1.882(2) Å, respectively. 相似文献
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