Usefulness of graphical invariants in quantitative structure-activity correlations of tuberculostatic drugs of the isonicotinic acid hydrazide type.

Quantitative structure-activity relationship (QSAR) studies have been performed for a series of 2-substituted isonicotinic acid hydrazides utilizing theoretical molecular descriptors. 223 topological (topostructural and topochemical) indices along with seven geometrical descriptors were computed for the prediction of antibacterial activity against Mycobacterium tuberculosis. Ridge-regression models assessed by cross-validated R2 have been formulated, and a comparative study on the relative effectiveness of physicochemical vis-à-vis theoretical molecular descriptors performed. The models developed clearly indicate the supremacy of structure-activity over property-activity relationships in the current study and can be used to evaluate the potential tuberculostatic activity of other INH derivatives, real or hypothetical.