title: Mode of action and quantitative structure-activity correlations of tuberculostatic drugs of the isonicotinic acid hydrazide type.
abstract: Quantitative structure-activity studies have been performed for a series of 2-substituted isonicotinic acid hydrazides by correlating electronic, steric, and lipophilic properties of the substituents with the biological activity date (MIC) from serial dilution tests with Mycobacterium tuberculosis (strain H 37 Rv). The reaction rates for the quaternization of 2-substituted pyridines with methyl iodide were also determined. The rate constants show a similar dependence on the steric and electronic effects of the substituents as the antibacterial activities of the corresponding pyridine-4-carboxylic acid hydrazides. The obtained correlations give evidence that the reactivity of the pyridine nitrogen atom is essential for the biological activity of 2-substituted isonicotinic acid hydrazides and seem to support the hypothesis that isonicotinic acid derivatives are incorporated into an NAD analogue.
mesh_terms: D000995:Antitubercular Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D007538:Isoniazid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D012044:Regression Analysis; D013329:Structure-Activity Relationship
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid