**3. Zinc ionophores**

Ionophores are ion carrier molecules that reversibly bind and transport ions through biological membranes. Many ionophores are lipid-soluble ion transporters that traverse the cell membrane. Ionophores accelerate ion transport through hydrophobic membranes such as liquid polymeric membranes (carrier-based ion-selective electrodes), lipid bilayers in live cells, or synthetic vesicles (liposomes). A hydrophilic core and a hydrophobic section interact with the membrane in the structure of an ionophore [53]. Many microorganisms, fungi, and plants naturally manufacture ionophores, which import ions into their cells and function as a defense against competing or harmful species. Ionophores made from synthetic materials have also been developed. Ionophores that select for cations and anions have a wide range of uses in the analysis [54]. When paired with the ion they bind, these chemicals have been proven to have a variety of biological effects as well as a synergistic impact [55]. Ionophores change the permeability of biological membranes in the direction of certain ions for which they have affinity and selectivity (**Figure 1**). An ionophore has a hydrophilic core and a hydrophobic section that interacts with the membrane in terms of structure. An ionophore-ion complex is formed when ions are bound to the hydrophilic center. X-ray crystallography has confirmed the structure of the ionophore-ion complex [58].

Zinc ionophores (**Table 1**; **Figure 2**) have been shown to inhibit replication of various viruses in vitro, including coxsackievirus [63, 65], equine arteritis virus [68], coronavirus [68], HCV [69], HSV [70], HCoV-229E [71], HIV [72, 73], mengovirus [63, 65], MERS-CoV [71], rhinovirus [65], SARS-CoV-1 [68], and Zika virus [74].
