Hexamminecobalt (III) Chloride as a Broad-Spectrum Antiviral Complex 

Eddie L. Chang1 *, Gene G. Olinger2 , Lisa E. Hensley2 , Calli M. Lear2 , Corinne E. Scully2 , Marie K. Mankowski3 , Roger G. Ptak3 , Dzung C. Thach4 and D. Andrew Knight5 

1 Center for Bio/Molecular Science and Engineering, 4555 Overlook Avenue SW, Washington, DC20375, USA 

2 United States Army Medical Research Institute of Infectious Diseases, Division of Virology, 1425 Porter Street, Frederick, Maryland, USA

3 Infectious Disease Research Department, Southern Research Institute, 431 Aviation Way, Frederick, MD, 21701, USA 

4 Laboratory of Infectious Diseases, National Institute of Allergies and Infectious Diseases, NIH, Department of Health and Human Services, Bethesda, MD 20892, US

Abstract 

Metal ion complexes have the potential to form novel types of antiviral compounds, due to their ability to form octahedral and square-planar molecular geometries and their intrinsic charge density. Previously it has been shown that hexamminecobalt(III) chloride (Cohex) has antiviral properties against Sindbis virus (SINV) and adenovirus. Here, we report that Cohex also exhibits activities against two isolates of human immunodeficiency virus (HIV) and the Zaire Ebola (ZEBOV) strain expressing green fluorescent protein (GFP). The therapeutic indices for antiviral activity against the HIV isolates were similar to that found for SINV. Cohex was also effective in decreasing the host translation of viral GFP in four different cell-lines infected with ZEBOV. Toxicity studies in mice found no deleterious effects at up to 8 mg/kg. The 8 mg/kg concentration also prolonged survival of mice infected with ZEBOV. These results point to the potential of Cohex as a new type of broad-spectrum antibiotic compounds