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A fast new approach to pharmacophore mapping and its application to dopaminergic and benzodiazepine agonists 总被引:3,自引:0,他引:3
Yvonne C. Martin Mark G. Bures Elizabeth A. Danaher Jerry DeLazzer Isabella Lico Patricia A. Pavlik 《Journal of computer-aided molecular design》1993,7(1):83-102
Summary In the absence of a 3D structure of the target biomolecule, to propose the 3D requirements for a small molecule to exhibit a particular bioactivity, one must supply both a bioactive conformation and a superposition rule for every active compound. Our strategy identifies both simultaneously. We first generate and optimize all low-energy conformations by any suitable method. For each conformation we then use ALAD-DIN to calculate the location of points to be considered as part of the superposition. These points include atoms in the molecule and projections from the molecule to hydrogen-bond donors and acceptors or charged groups in the binding site. These positions and the relative energy of each conformation are the input to our new program DISCO. It uses a clique-detection method to find superpositions that contain a least one conformation of each molecule and user-specified numbers of point types and chirality. DISCO is fast; for example, it takes about 1 min CPU to propose pharmacophores from 21 conformations of seven molecules. We typically run DISCO several times to compare alternative pharmacophore maps. For D2 dopamine agonists DISCO shows that the newer 2-aminothiazoles fit the traditional pharmacophore. Using site points correctly identifies the bioactive enantiomers of indoles to compare with catechols whereas using only ligand points leads to selecting the inactive enantiomer for the pharmacophore map. In addition, DISCO reproduces pharmacophore maps of benzodiazepines in the literature and proposes subtle improvements. Our experience suggests that clique-detection methods will find many applications in computational chemistry and computer-assisted molecular design. 相似文献
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The crystal structure of K[CH3Se {Al(CH3)3}3] · 2C6H6 has been determined from single-crystal X-ray diffraction data collected by counter methods. The compound crystallizes in the triclinic space group P with cell dimensions a = 17.165(7), b = 10.144(7), c = 10.156(7)Å, α = 119.26(5), β = 104.07(5), ψ = 80.51(5)°, and Dc = 1.12 gcm?3 for Z = 2. Least-squares refinement gave a final R value of 0.083 for 1967 independent observed reflections. One of the two benzene molecules in the asymmetric unit has been located by difference Fourier techniques. Because of either extreme disorder or high thermal motion, the aromatics make practically no contribution to the X-ray scattering. The selenium atom in the anion exhibits tetrahedral coordination. The Al-Se bond lengths average 2.578(5)Å, and the Se-C distance is 1.93(2)Å. 相似文献
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