Adenine and guanine derivatives for the treatment of hepatitis virus infections

摘要

A novel nucleic acid derivative represented by the following general formula (I) and physiologically acceptable salt thereof which are expected to have an antiviral activity: <IMAGE> (I) wherein B represents a nucleic acid base derivative; A1 and A2 represent, independently of each other, OR1 or OCOR1; R1 represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; l represents a number of 0 or 1; and m and n each represents an integer of 0-2; provided that when l and m are 0, n is 0 or 2.