# Copper(II) Complexes of Selected Acylhydrazones as Potential Biological Agents

## TL;DR

This study creates new copper complexes with acylhydrazones and finds they show strong antibacterial activity, especially against Gram-positive bacteria, with low toxicity to normal cells.

## Contribution

The paper introduces novel copper(II) complexes with acylhydrazone ligands exhibiting enhanced antibacterial activity and low toxicity.

## Key findings

- The copper complexes showed high antimicrobial activity, especially against Gram-positive bacteria.
- The compounds had lower MIC and MBC values than reference substances for specific bacterial strains.
- The complexes showed no toxicity towards normal cell lines.

## Abstract

In the current research a series of new copper(II) complexes with novel acylhydrazone ligands were synthesized and their antibacterial and anticancer activities were determined. The complexes were characterized by molecular spectroscopy (FT-IR and UV-Vis) and conductivity measurements. Additionally, their structure was confirmed by single-crystal X-ray analysis. The crystallographic data revealed that all compounds are mononuclear Cu(II) species. The Cu(II) ion is four-coordinated by the ONO donor set from mono-deprotonated hydrazone ligand and one Cl¯ anion, forming distorted square-planar geometry. The biological studies revealed that the compounds exhibit high antimicrobial activity, especially against Gram-positive bacteria, in some cases greater than the reference substances, and better activity than free ligands. The tested complexes possessed the lowest MIC and MBC values towards Staphylococcus epidermidis ATCC 12228 and Micrococcus luteus ATCC 10240. Furthermore, they showed no toxicity towards normal cell lines.