Hansch applications

F. P. Schafer Principles of Dye Laser Operation. -B. B. Snavely Continuous-Wave Dye Lasers. -C V. Shank, E. P. Ippen Mode-Locking of Dye Lasers. -K.H. Drexhage SiniciUTQm6 Properties of Laser Dyes. - T. W. Hansch Applications of Dye Lasers. - FP Schafer Progress in Dye Lasers September 1973 till March 1977. 

This section includes veterinary applications. The antiviral, bactericidal, and antimicrobial applications of 2-aminothiazoles and 2-imino-4-thiazolines are summarized in Table VI-7. They show a marked anti-trichonomicidal activity, which has even been quantitatively measured by the Hansch approach (797). The antiparasitic action of these compounds has been investigated for some compounds and is summarized in Table VI-8 interesting results were obtained with aminotrozal (1348). 

C Hansch, A Leo. Exploring QSAR Fundamentals and Applications in Chemistry and Biology. Washington, DC American Chemical Society, 1995. 

Hansch C, Leo A. Exploring QSAR. 1. Eundamentals and applications in chemistry and biology. Washington DC American Chemical Society, 1995. 

Attempts have been made to apply the structure-activity concept (Hansch and Leo 1995) to environmental problems, and this has been successfully applied to the rates of hydrolysis of carbamate pesticides (Wolfe et al. 1978), and of esters of chlorinated carboxylic acids (Paris et al. 1984). This has been extended to correlating rates of biotransformation with the structure of the substrates and has been illustrated with a number of single-stage reactions. Clearly, this approach can be refined with the increased understanding of the structure and function of the relevant degradative enzymes. Some examples illustrate the application of this procedure ... 

Ghose, A. K., Crippen, G. M. The distance geometry approach to modeling receptor sites In Comprehensive Medicinal Chemistry. The Rational Design, Mechanistic Study and Therapeutic Application of Chemical Compounds, Hansch, C.,... 

A difficulty with Hansch analysis is to decide which parameters and functions of parameters to include in the regression equation. This problem of selection of predictor variables has been discussed in Section 10.3.3. Another problem is due to the high correlations between groups of physicochemical parameters. This is the multicollinearity problem which leads to large variances in the coefficients of the regression equations and, hence, to unreliable predictions (see Section 10.5). It can be remedied by means of multivariate techniques such as principal components regression and partial least squares regression, applications of which are discussed below. 

The octanol-water partition coefficient Kow is widely used as a descriptor of hydrophobicity. Variation in /fow is primarily attributable to variation in activity coefficient in the aqueous phase (Miller et al. 1985) thus, the same correlations used for solubility in water are applicable to /fow. Most widely used is the Hansch-Leo compilation of data (Leo et al. 1971, Hansch and Leo 1979) and related predictive methods. Examples of Kow correlations are ... 

The applicability of Eq. (45) to a broad range of biological (i.e., toxic, geno-toxic) structure-activity relationships has been demonstrated convincingly by Hansch and associates and many others in the years since 1964 [60-62, 80, 120-122, 160, 161, 195, 204-208, 281-285, 289, 296-298]. The success of this model led to its generalization to include additional parameters in attempts to minimize residual variance in such correlations, a wide variety of physicochemical parameters and properties, structural and topological features, molecular orbital indices, and for constant but for theoretically unaccountable features, indicator or dummy variables (1 or 0) have been employed. A widespread use of Eq. (45) has provided an important stimulus for the review and extension of established scales of substituent effects, and even for the development of new ones. It should be cautioned here, however, that the general validity or indeed the need for these latter scales has not been established. 

Hansch, C. and Leo, A. Calculation of octanol-water partition coefficients by fragments in Exploring QSAR fundamentals and applications in chemistry and biology. Am. Chem. Soc. 

Hansch, C., Sammes, P.G., and Taylor, J.B. (Eds.) Comprehensive Medicinal Chemistry The Rational Design, Mechanistic Study, and the Therapeutic Application of Chemical Compounds. Pergamon Press, Oxford, 1990. 

Each of these descriptor sets is derived from, or related to, the Hansch and Leo descriptors with the expectation that they would be widely applicable. Taken together the VSA descriptors define, nominally, a 10 + 8 + 14 = 32 dimen-... 

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