Synthesis, Evaluation of Biological Activity, and Structure–Activity Relationships of New Amidrazone Derivatives Containing Cyclohex-1-ene-1-Carboxylic Acid

Abstract

In recent years, the incidence of acute and chronic inflammatory diseases has increased significantly worldwide, intensifying the search for new therapeutic agents, especially anti-inflammatory drugs. Therefore, the aim of this work was to synthesize, biologically assess, and explore the structure–activity relationships of new compounds containing the cyclohex-1-ene-1-carboxylic acid moiety. Six new derivatives, 2a–2f, were synthesized through the reaction of amidrazones 1a–1f with 3,4,5,6-tetrahydrophthalic anhydride. Their toxicity was evaluated in cultures of human peripheral blood mononuclear cells (PBMCs). Additionally, their antiproliferative properties and effects on the synthesis of TNF-α, IL-6, IL-10, and IL-1β were assessed in mitogen-stimulated PBMCs. The antimicrobial activity of derivatives 2a–2f was determined by measuring the minimal inhibitory concentration (MIC) values against five bacterial strains—Staphylococcus aureus, Mycobacterium smegmatis, Escherichia coli, Yersinia enterocolitica, and Klebsiella pneumoniae—and the fungal strain Candida albicans. All compounds demonstrated antiproliferative activity, with derivatives 2a, 2d, and 2f at a concentration of 100 µg/mL being more effective than ibuprofen. Compound 2f strongly inhibited the secretion of TNF-α by approximately 66–81% at all studied doses (10, 50, and 100 µg/mL). Derivative 2b significantly reduced the release of cytokines, including TNF-α, IL-6, and IL-10, at a high dose (by approximately 92–99%). Compound 2c exhibited bacteriostatic activity against S. aureus and M. smegmatis, while derivative 2b selectively inhibited the growth of Y. enterocolitica (MIC = 64 µg/mL). Some structure–activity relationships were established for the studied compounds.

Keywords

• amidrazones
• anti-inflammatory
• antiproliferative
• antibacterial
• cytokines
• cyclohexene