The present invention relates to a compound of formula (I) or formula (II) formula (I) formula (II) or a salt thereof for use in treating or preventing a viral disease or viral infection, wherein within formula (I) or (II) (A) A is H or OH, X is CH3, and R1 and R2 are H and R3 is selected from the group consisting of a linear or branched C3 to C8 alkyl, a cycloalkyl, an alkenyl, a phenylalkenyl (preferably styryl), an aryl, and a heteroaryl; or (B) A is H or OH, X is CH3, and R2 is H and R1 and R3 are independently selected from the group consisting of a linear or branched C3 to C8 alkyl, a cycloalkyl, an alkenyl, a phenylalkenyl (preferably styryl), an aryl, and a heteroaryl; or (C) A is H or OH, X is H or CH3, and R1 to R3 are each independently selected from H, F, Cl, Br, or I, provided that at least one of R1 to R3 is F, Cl, Br, or I; or wherein within formula (II) (D) A is H or OH, X is CH3, and R1 to R3 are H, and wherein for (A) and (B) the heteroatom of the heteroaryl is selected from S, O and N, and the linear or branched C3 to C8 alkyl, cycloalkyl, alkenyl, phenylalkenyl (preferably styryl), aryl, and heteroaryl are unsubstituted or are substituted, preferably substituted with one or more of F, Cl, Br, I, -OH, -SH, -NH2, -N3, -NO2, - CN, -CHO, -COOH, or -CONH2 and more preferably with one or more F or Br.
