Studies on antimicrobial agents. 1. Synthesis and relation between the antimicrobial activities and certain physicochemical properties of some N'-(pyridinoacetyl) fatty acid hydrazides.

A new series of N'-(pyridinioacetyl)alkanoic and -benzoic acid hydrazides, as chloride salts, and some cyclic analogues produced ring closure have been synthesize and tested in a search for more effective germicides. Physicochemical parameters, such as surface tension, critical micelle concentration, and thermodynamic activity. (Ferguson values), were also determined. Staphylococcus aureus and Streptococcus pyogenes were the most susceptible of the organisms tested. N'-(Pyridinoacetyl)hexadecanoic acid hydrazide exhibited the highest toxicity to Staph. aureus and fungi. The mean surface tension of the equitoxic solutions is 59.8 +/- 0.3 dyn/cm for bacteria and 51.65 +/- 0.1 dyn/cm for fungi. N'-(Pyridinoacetyl)octadecanoic acid hydrazide and N'-(pyridinoacetyl)-9-ocadecenoic acid hydrazide exhibit the highest toxicity to S. pyogenes (1.1 x 10(-6) M). The surface tension of their equitoxic solutions and their Ferguson values indicate that these compounds may act through a different mechanism.