The invention relates to compounds of general formula (I); in which R is an amino or guanidino group; R.sup.2 is acetyl or trifluoroacetyl; X is CONH, SO.sub.2NH, NHCO or NHCONH; m is either 0 or 1; n is an integer from 2 to 6; q is an integer from 0 to 3; and Y is hydrogen or an aromatic substituent, or a pharmaceutically acceptable derivative thereof; methods for their preparation, pharmaceutical formulations containing them or their use in the prevention or treatment of a viral infection ##STR00001##