Abstract: Compounds having the structure of formula I are described wherein R, R?, R1, R2, and R3 are as defined in the specification. The compounds can inhibit hepatitis C virus (HCV) replication, and in particular the function of the HCV NS5A protein.

Abstract: A method of treating HIV infection in a human patient wherein the infecting HIV strain has become resistant to atazanavir, the method comprising administration of a therapeutically effective amount of a combination of atazanavir or a pharmaceutically acceptable salt thereof, and at least one other HIV protease inhibitor. A method for enhancing the effectiveness of a second HIV protease inhibitor in treating HIV infection in a human patient whose HIV strain has become resistant to atazanavir or a pharmaceutically acceptable salt thereof, comprising administering to said human patient an amount of atazanavir or a pharmaceutically acceptable salt thereof effective in maintaining the resistant strain, in combination with the second HIV protease inhibitor. The resistance to atazanavir in the human is manifested by the existence of the signature mutation consisting of I50L mutation in the HIV protease.

Abstract: Compounds having the structure of formula I are described wherein R, R?, R1, R2, and R3 are as defined in the specification. The compounds can inhibit hepatitis C virus (HCV) replication, and in particular the function of the HCV NS5A protein.

Abstract: Disclosed are combination pharmaceutical agents for the treatment of an HCV infection comprising a compound effective to inhibit the function of the HCV NS5A protein and another compound having anti-HCV activity. Compounds which can inhibit the function of the NS5A protein having the structure of formula I are described wherein R, R?, R1, R2, and R3 are as defined in the specification. The other compounds having anti-HCV activity are effective to inhibit the function of a target selected from the group consisting of HCV metalloprotease, HCV serine protease, HCV polymerase, HCV helicase, HCV NS4B protein, HCV entry, HCV assembly, HCV egress, HCV NS5A protein, IMPDH and a nucleoside analog for the treatment of an HCV infection.

Abstract: The pentapeptide Val Val Asn Asp Leu has been found to be the shortest peptide sequence that inhibits the activity of the ribonucleotide reductase enzyme of herpes simplex virus in vitro thereby inhibiting viral replication. Longer peptides containing the foregoing pentapeptide sequence are more potent inhibitors.