Journal of Advances in Medical and Pharmaceutical Sciences

Aim: To develop good and rational Quantitative Structure Activity Relationship (QSAR) mathematical models that can predict to a significant accuracy the anti-Staphylococcus aureus Minimum inhibitory concentration (MIC) of Ni-Schiff base complexes.

Place and Duration of Study: Department of Chemistry (Physical Chemistry unit), Ahmadu Bello University, Zaria, Nigeria, between January and June 2015.

Methodology: A set of 36 nickel-Schiff base complexes with their antibacterial activities in terms of minimum inhibitory concentration (MIC)  against the gram-positive bacteria, Staphylococcus aureus were selected for 0D, 1D, 2D and 3D quantitative structure activity relationship (QSAR) analysis by means of Density Functional Theory (DFT) using the Becke’s three-parameter hybrid functional (B3LYP) and 6-31G^* basis set. The computed descriptors were correlated with their experimental MIC. Genetic function approximation (GFA) method and Multi-linear regression analysis (MLR) was used to derive the most statistically significant QSAR model.

Results: Among the obtained QSAR models, the most statistically significant one was a tri- parametric linear equation with the squared correlation coefficient R² value of 0.9399, adjusted squared correlation coefficient R ²_adj value of 0.9313 and Leave one out (LOO) cross validation coefficient (Q²) value of 0.9074. An external set was used for confirming the predictive power of the model, its R²_pred = 0.9725.

Conclusion: The QSAR results reveal that molecular size and polarity predominantly influence the anti-Staphylococcus aureus activity of the complexes. The wealth of information in this study will provide an insight to designing novel bioactive nickel-schiff base complexes that will curb the emerging trend of multi-drug resistant strain of Staphylococcus aureus.