Infection with Hepatitis C Virus (HCV) is the major cause of chronic and persistent hepatitis, liver cirrhosis, and Hepatocellular Carcinoma (HCC) and accordingly main reason for liver transplantation needs. In fact, only a small fraction (20%-30%) of the infected people resolve from the acute phase of HCV infection while majority develop the chronic state which may finally end up with adverse liver diseases (cirrhosis and HCC). Around 170 Million individuals are infected with HCV and at least 350,000 people die each year from this infection while there is no approved vaccine available against this threatening infection to date.

Globally, hepatitis B viral infection is a significant health problem leading to one million deaths annually from liver failure, cirrhosis and hepatocellular carcinoma. It has been estimated that 400 million people worldwide are carries of Hepatitis B Virus (HBV), which is an important cause of morbidity and mortality after kidney transplantation.

Zinc is an essential trace element playing fundamental roles in the cellular metabolism and can be found in all tissues. It acts mostly by binding a wide range of proteins, thus affecting a broad spectrum of biological processes, which include cell division, growth and differentiation.

New conjugated compounds containing the coumarin moiety attached to mono- or bis-heterocyles have been synthesized. In >100 new conjugates of five categories, some of them exhibit significant and appealing activity against Hepatitis C Virus (HCV). The heterocycles therein include adenine, benzimidazole, benzothiazole, benzoxazole, guanine, hypoxanthine, imidazole, imidazopyridine, and purine. Use of the thiomethylene (–SCH2 –) linker to connect a coumarin moiety and a purine or imidazole nucleus leads to the conjugates with greater activity and selectivity than others. Various substituents, including CH3 , F, Cl, Br, OCH3 , OAc, CO2 H, COPh, NO2 , β-D-glucose, and β-D-ribofuranose, are also attached to the core nuclei. Incorporation of a halogen substituent (particularly the Br) onto the coumarin nucleus generally enhances the anti-HCV activity from double-digit to single-digit of µM potency. The structure-activity relationship is established, which is of value to the development of new anti-HCV drugs.