Synthesis and Antimicrobial Resistant Modulatory Activity of 2,4-Dinitrophenylhydrazone Derivatives as Agents against Some ESKAPE Human Pathogens

A library of six novel phenylhydrazones were synthesized and evaluated for their in vitro antimicrobial and resistance modulating activity against a panel of Gram-positive, Gram-negative, and fungal species. The compounds were produced in good yields of 60–92% w/w and characterized using melting point, UV-visible spectroscopy, infrared, and nuclear magnetic resonance (1H, 13C, and DEPT-Q) techniques. Mass spectroscopy was used to confirm the identity of one of the most active compounds, 5 [SA5]. The phenylhydrazones showed activity against all the six selected microorganisms with minimum inhibitory concentration (MIC) values of the most active compounds, 1 [BP1] and 5 [SA5], at 138 µM (Klebsiella pneumoniae) and 165 µM (Streptococcus pneumoniae), respectively. Compound 1 [BP1] further demonstrated a high resistance modulatory activity at 1.078 µM against Streptococcus pneumoniae and Klebsiella pneumoniae