Structure property relationships of amino acids and some dipeptides

Abstract

A molecular connectivity model of the crystal densities and specific rotations of some natural amino acids and of the longitudinal relaxation rates of some natural amino acids and cyclic dipeptides is presented. While crystal densities and relaxation rates are better described by a set of three valence molecular connectivity indices {D (v),(0) X (v),(1) X (v)}, specific rotations are better described by a set of two simple molecular connectivity indices {(1) X,(0) X}. Relaxation rates are, also, well described by the simple molecular connectivity {D,(1) X} index set. Use of orthogonal indices, derived from the corresponding ordinary indices shows, in the case of specific rotations, the possibility to condense the information by the aid of a single high quality descriptor underlining, thus, the versatility of these indices and also their dependence on the orthogonalisation process.

Application of topological and physicochemical descriptors: QSAR study of phenylamino-acridine derivatives

“…44 Initially we have used Pogliani's quality factor Q 45,46 for investigating predictive power of the various parameters and finally we used the cross validation parameters to prove our findings. The comparisons of various models by cross validation parameters are shown in Table 5 (see p. 145) The inter-correlation of various parameters and the correlation of parameters with biological activity (logK) are presented in Table 4 When earlier work 43 was repeated using an entirely new set of parameters, the new results should show either better statistics or be of an equivalent quality.…”

QSAR Studies on Akt activities of fused bicyclic pyrrolizinones

“…Stepwise regression analysis was done by using SPSS 7.5 version. In this series, some significant QSAR models have been obtained which are given below:\ (3,13) = 28814, P = 1.425, S = 9477 In all the QSAR reported here, n is number of data points, R is the coefficient of regression or correlation coefficient, R 2 represents coefficient of determination, SE is the standard error of estimate, R 2 A is adjusted R 2 , F is variance ratio 21,22 , Q is the quality of fit 23,24 and data within the parenthesis is confidence interval. The validity of the above QSAR equations was further confirmed, using the cross validation method.…”

QSAR Studies on Ant Malarial Activity of Diverse Set of Compounds for D6 Strain of P. falciparum

“…The statistical details suggest following models: ; F is the Fisher's ratio and Q is the Pogliani's quality factor [9] which is the ratio of R/Se. However, this model explains only 75% of variance.…”

“…Grigorov et al [1] correlated the antimalarial activity of a series of synthetic 1,2,4-trioxanes with molecular structure using this technique for which they have used CATALYST package. [9] Girone´s et al studied the application, within a quantum similarity framework, of the kinetic energy based quantum similarity measures in the evaluation of the antimalarial activity. The authors used two molecular sets composed of artemisinin derivatives, in which the 50% inhibition of synthesis and reduction of hidrofolate (IC50) in different P. falciparum clone were analysed.…”