MOLECULAR STRUCTURES BY COMPUTATIONAL METHODS

An extensive series of studies for the prediction of aqueous solubility has been reported in the literature, as summarized by Lipinski et al. [15] and jorgensen and Duffy [16]. These methods can be categorized into three types 1 correlation of solubility with experimentally determined physicochemical properties such as melting point and molecular volume 2) estimation of solubility by group contribution methods and 3) correlation of solubility with descriptors derived from the molecular structure by computational methods. The third approach has been proven to be particularly successful for the prediction of solubility because it does not need experimental descriptors and can therefore be applied to collections of virtual compounds also. 

New ways to represent structure data became available through molecular modeling by computer-based methods. The birth of interactive computer representation of molecular graphics was in the 196Ds. The first dynamic molecular pictures of small molecules were generated in 1964 by Lcvinthal in the Mathematics and Computation (MAC) project at the Electronic Systems Laboratoiy of the Massachusetts... 

Blood-brain barrier permeation of 7, among other drugs, was predicted from its three-dimensional molecular structure by a computational method (0OJMC2204). The combination of molecular topological methods using 137 quinolones, including 7 provided an excellent tool for the design of new... 

Chou, J.T., Jurs, PC. (1979) Computation of partition coefficients from molecular structures by a fragment addition method. In Physical Chemical Properties of Drugs. Medical Research Series, Vol. 10, Yalkowsky, S.H., Sindula, A.A., Valvani, S.C., Editors, Marcel Dekker, New York. pp. 163-199. 

Characterization Techniques for Pitch Materials. Among a number of characterization techniques developed in Japan, the technique due to the members of the Society of Heavy Oil, led by Kunugi, stands out as particularly useful. The analytical data are treated by computer methods to construct average molecular structures for the carbonaceous materials. Sanada s group in Hokkaido University used high-temperature NMR and ESR data obtained by in situ measurements of pitch materials in molten salt (21). Much information on mesophase behavior during the heat-treatment process was obtained in this way. 

Quantitative structure-activity relationship (QSAR) dates back to the nineteenth century and is a computer-based tool that attempts to correlate variations in structural or molecular properties of compounds with their biological activities. These physicochemical descriptors, which include parameters to account for hydrophobicity, topology, electronic properties, and steric effects, are determined empirically or, more recently, by computational methods. The premise is that the structure of a chemical determines the physiochemical properties and reactivities that underlie its biological and toxicological properties. Being able to predict potential adverse effects not only aids in the designed development of new chemicals but also reduces the need for animal testing. It may ultimately or potentially lead to better... 

Nikolai B. Ulyanov studied mathematics in Moscow State University and worked on computational modeling of DNA bending as part of his Ph.D. project in the group of Dr. Victor Zhurkin in the Engelhardt Institute of Molecular Biology in Moscow. He was a postdoctoral fellow with Prof. Ramaswamy Sarma studying NMR spectroscopy of DNA at the State University of New York at Albany. Currently he is Associate Adjunct Professor at the University of California at San Francisco. His research interests focus on the structure and dynamics of nucleic acids, studied by computational methods and NMR. 

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