Synthesis and Antibacterial Activity of Hydrazones of Isonicotinic and Salicylic Acids Based on Acetyl Derivatives of Coumarin and Benzo[g][1,3,5]Oxadiazocine

In recent decades, the efforts of many researchers in the sphere of organic chemistry, physics and pharmacol-ogy have been focused on the search for new agents with pronounced antibacterial and especially antifungal activity. This is due to the widespread increase in the resistance of many bacterial strains and fungi to antibi-otics and antifungal drugs available in medical practice. In this regard, the number of works related to the synthesis of new potential antibiotics from the most diverse class of organic derivatives, which either include known pharmacophore groups or represent a new structural class of compounds with unknown and unex-plored activity, is increasing in the scientific literature. In this work, new previously undescribed hydrazones derivatives were obtained on the basis of physiologically active isonicotinic and salicylic acid hydroxides and laboratory-available acetyl-substituted heterocycles, namely 3-acetyl-2H-chromen-2-one 3, 2-acetyl-3H-benzo[f]chromen-3-one 4 and 2,6-methanobenzo[g][1,3,5]oxadiazocine 5. The obtained hydrazones structure is explicitly proved by IR and 1H, 13C NMR spectroscopy data. The synthesized six new hydrazones under-went biological screening for antibacterial and antifungal activity on strains of microorganisms, namely gram-positive bacterium Staphylococcus aureus 209P, gram-negative bacterium Pectobacterium carotovorum VKM-B1247, and yeast-like fungus Candida albicans ATCC 10231. Screening revealed three compounds with antimicrobial activity and one promising compound — (E)-2-hydroxy-N’-(1-(2-oxochroman-3-yl)ethylidene)benzohydrazide 9, which also exhibits antifungal activity along with antimicrobial activity.