FIELD: medicine. SUBSTANCE: described are new phosphonolipids of carboxylic acids of formula I: 
and salts thereof wherein R1 is linear C9-C13, alkyl; R2 is linear C8-C12 alkyl; R3 is hydrogen, linear C1-C6 alkyl or benzyl, n is 0-2, m is 0-3. Said compounds have antiviral activity and are useful in medicine. Also described is antiviral agent comprising, as active ingredient, compound of formula I. EFFECT: improved properties of the title compounds. 8 cl, 4 ex, 9 tbl
