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: ##STR1## wherein B represents a nucleic acid base derivative; A.sup.1 and A.sup.2 represent, independently of each other, OR.sup.1 or OCOR.sup.1 ; R.sup.1 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.
以下是一种新的核酸衍
生物及其生理上可接受的盐,预期具有抗病毒活性,其
化学式如下(I):##STR1##其中B代表核酸碱基衍
生物;A.sup.1和A.sup.2分别独立地代表OR.sup.1或OCOR.sup.1;R.sup.1代表氢原子,取代或未取代的烷基或取代或未取代的芳基;l代表0或1的数字;m和n分别表示0-2的整数;但当l和m都为0时,n为0或2。