Method Of Producing Compound Having Anti-Hcv Activity

There is provided a convenient and inexpensive method of producing a compound which has a high activity of inhibiting replication of hepatitis C virus (HCV) and is useful for preventing and treating a liver disease caused by HCV infection. It is a method of biologically producing a compound represented by the formula (1): [wherein A represents a hydrogen atom, a straight or branched alkyl group having 1 to 8 carbon atoms, or the like], or a pharmaceutically acceptable salt thereof, a method comprising adding an amino acid derivative represented by the formula (3): [wherein A has the same meaning as defined for the compound of the above formula (1); and R represents a hydrogen atom, a straight or branched alkyl group having 1 to 8 carbon atoms, or the like], or a salt thereof into the fungal mycelium or the culture medium/culture broth of a filamentous fungal strain having an ability to produce the compound represented by the formula (2): to thereby cause the fungal strain to directly produce the compound of the formula (1).