Perspectives of medicinally privileged chalcone based metal coordination compounds for biomedical applications.

Recent clinical reports have highlighted the increasing occurrence of drug resistance of known therapeutics. Particularly, antibiotic resistant microorganisms and multidrug resistance have posed a serious threat to health of the people. Since ages, metals and metal complexes have played key role in the development of contemporary chemotherapy. Many organic compounds used in medicine do not have a purely organic mode of action and require traces of metal ions directly or indirectly for activation or biotransformation. For decades, the metallopharmaceuticals have attracted researchers across the globe due to their amplified therapeutic/modulatory effect by altering the pharmacokinetic and pharmacodynamic properties of the complexes towards biological receptors. Medicinally privileged natural and (semi)-synthetic chalcones have already been reported to possess a wide variety of pharmacological effects by modulating diverse molecular targets. The presence of carbonyl, hydroxyl, phenolic oxygen and/or heteroatom(s) in heterocyclic ring system makes them excellent chelating ligand for metal coordination. Particularly, the metal complexes of bidentate chalcone/Schiff base analogs and ferrocenyl chalcones have shown great potential. In this review, the chelating/coordinating property of substituted chalcones, the therapeutic, catalytic, chemosensing and photosensitizing potential of various metal-chalcone complexes, their structural features and structure activity relationships (SARs) have been highlighted. Further, the understanding of coordination mode, their stoichiometric characteristics, and mode of action(s), this review may be helpful for medicinal and bioinorganic chemists to design and develop novel, more potent, safe, selective and cost-effective chalcone-based coordination compounds for diverse biomedical applications.