Highly conjugated curcumin analog based copper complexes towards tuberculosis: synthesis, characterization and antimycobacterial activity

Background Current first-line drugs for the treatment of tuberculosis consist of, i.e., isoniazid (INH), rifampin (RIF), ethambutol (EMB), pyrazinamide (PZA), and streptomycin (STR). Resistance to the first-line drugs causes treatment failure and necessitates the use of the drugs with a prolonged period of therapy. New anti-tuberculous agents, especially the ones with novel mechanisms of action are urgently required. Curcumin is a naturally occurring yellow pigment obtainable from the rhizomes of perennial herb Curcuma longa Linn., has been shown to act upon several important molecular targets in malignancy and inflammatory cascades and hence is used to treat various disorders including arthritis, Crohn’s disease, cardiovascular disorders, psoriasis, cancers, and other pathologies. However, poor water solubility and unsatisfactory pharmacokinetics of curcumin necessitate search for new curcumin analogs. In the present work, we described the synthesis and structural characterization of highly conjugated curcumin analogs (acetoacetanilide) Knoevenagel condensates, their Schiff bases, and corresponding copper conjugates.