Selective Copper(II) Complexes against Mycobacterium tuberculosis.

Area of Science:

• Coordination Chemistry
• Medicinal Chemistry
• Materials Science

Background:

• Tuberculosis (TB) remains a significant global health challenge, necessitating the development of new therapeutic agents.
• Quinoline derivatives and their metal complexes are explored for diverse biological activities, including antimicrobial properties.
• Understanding structure-activity relationships is crucial for designing effective antitubercular compounds.

Purpose of the Study:

• To synthesize and characterize novel quinoline derivatives and their copper(II) complexes.
• To evaluate the in vitro biological activity of these compounds against Mycobacterium tuberculosis (Mtb).
• To investigate the structural and electronic properties influencing their antitubercular efficacy.

Main Methods:

• Synthesis of five quinoline derivatives (DCQ, ACQ12, ACQ13, ACQ14, ACQophen) and their copper(II) complexes.
• Structural characterization using single-crystal and powder X-ray diffraction (PXRD).
• Spectroscopic analyses (IR, Raman, UV-vis) and Density Functional Theory (DFT) calculations.
• Biological evaluation of antitubercular activity and determination of selectivity indexes (SI).

Main Results:

• Successful synthesis and characterization of quinoline derivatives and their copper complexes with varying stoichiometries and coordination geometries.
• Cu-ACQophen complex demonstrated potent antitubercular activity (MIC90 ≈ 1.68 μmol L⁻¹) and a high selectivity index (SI = 48).
• Other complexes, including Cu-DQC and Cu-ACQ12, also exhibited promising selectivity indexes (>10).

Conclusions:

• The synthesized quinoline derivatives and their copper complexes represent a promising class of compounds for antitubercular drug development.
• The Cu-ACQophen complex shows significant potential as a lead compound due to its high efficacy and selectivity.
• Further research into these metal-organic compounds could lead to novel strategies for combating tuberculosis.