Antiviral effects of amphotericin B methyl ester.

The methyl ester of amphotericin B (AME) is water soluble, retains antifungal activity, and is significantly less toxic in mammals than amphotericin B. In contrast to amphotericin B, which is not water soluble, AME exhibits antiviral effects against vesicular stomatitis virus, herpes simplex virus types 1 and 2, Sindbis virus, and vaccinia virus in a plaque reduction assay. No antiviral effects could be demonstrated against the unenveloped adenovirus type 4 or echovirus type 11. The extent of virus inactivation was found to be dependent upon the AME concentration, contact time, and temperature. No consistent effect of the virus concentration on the probability of plaque-forming unit inactivation could be determined. The antiviral effects of AME were partially antagonized by the presence of serum. Binding of AME to vesicular stomatitis virus was demonstrated by the comigration of drug and virus in linear sucrose gradients. AME represents a new class of antiviral agents with activity at concentrations relevant to therapeutics. Sterol components of the host cell membrane that become incorporated into the viral envelope are postulated as the site of reaction with AME.