Paper Title
QSAR based Modeling of Anti Malarial Activities of Some Compounds against P. Falciparum using Selected Topological and Physiochemical Parameters

Abstract
A number of drugs have been investigated for their use in the treatment of malaria. However, new strains of P.falciparum resistant found against some of the existing drugs, which are causing a substantial deterioration in the clinical treatment. This has motivated the search for new anti malarial drugs that are effective against this strain of malaria, thus having a very high priority in anti malarial drug design. A set of 21 compounds has been chosen in the present study for its anti malarial activity reported in the form of log RA, . i.e. logarithm of relative activity (RA = IC50 of artemesinin / IC50 of analogue). The present study investigates the impact of topological parameters on the anti malarial activity of given set of compounds active against D-6, strains of P.Falciparum, using QSAR analysis, followed by its statistical evaluation using regression analysis. An indicator parameter has also been used signifying the presence of halogen atom at suitable position. The statistical analysis of the data produced the highest R2 value (0.9640) and R2 CV (0.9626) for the best penta parametric model suggested that almost 96% variance in the data could be explained using this model. The best model obtained showed the significance of connectivity indices in modeling the activity. A high value of third order connectivity indice and first order valence connectivity indice and low value of third order valence connectivity indice along with the presence of halogen atom attached to the phenyl ring are effective for modeling the activity. Index terms - QSAR, cross validation, topological parameters, regression and connectivity indices.