QSAR, Docking Study of Isatin Analogues as Anti-bacterial Agents for Design New Compounds

Computational chemistry is unique method in drug discovery which reduce cost. In this study 86 molecules containing isatin core were subjected to quantitative structure-activity relationship analysis and docking study to find the structure requirements for ligand binding. The structures were sketched and optimized in Hyperchem. The structural invariants used in this study were those obtained from whole molecular structures: by both hyperchem and dragon software (16 types of descriptors). Four chemometrics methods including MLR, FA-MLR, PCR and GA-PLS were employed to make connection between structural parameters and anticancer effects. MLR analysis explained the positive effect of the number of urea derivatives, thio urea, amide, thioamide, hydrazone, thiocarbohydrazone, nBnz with the halogen substitution on 5 position of isatin ring on the antimicrobial activity. It also shows nArCN, nPyridines have negative effects on the antimicrobial activity of studied compound.

The FA-MLR describes the effect of 3D-MORSE and Galvez Topological charge descriptors and on antimicrobial activity of the studied compounds. The quality of PCRA equation is better than those derived from FA-MLR. A comparison between the different statistical methods employed revealed that GA-PLS represented superior results and it could explain and predict 73% and 68% of variances in the –LogMIC data, respectively. Comparison between QSAR and docking analysis revealed that by decreasing in number of ring and lipophilicity (also Logp) for design of new compounds can have better activity. Substitutions such as urea, thiourea, thiocarbohydrazone, benzhydrazide as on isatin ring, can cause better interaction with receptor.