PROPHYLACTIC AND THERAPEUTIC USE OF MURAMYL PEPTIDES AND THEIR ANALOGUES AGAINST VIRAL INFECTIONS

1. A pharmaceutical composition for enteral or parenteral application, which composition contains, as sole active ingredient, an effective amount, but less than 1 % by weight, of a compound of the formula I see diagramm : EP0102319,P31,F1 in which the sugar moiety is derived from (D)-galactose, (D)-mannose or (D)-glucose, which compound has at an asymmetrically substituted C(-R**3) atom the (D)-configuration, at an asymmetrically substituted C(-R**6) atom the (L)-configuration and at an asymmetrically substituted C(-R**8) atom the (D)-configuration, and in which compound each of X**1 and X**2 independently to the other represents a group of the formula -O- or -N(R**14)-, R**14 representing hydrogen or lower alkyl, each of R**1, R**2, R**12 and R**13 independently represents a radical of the formula Ia -(Z**1-Y**1-X**3)n -A**1 in which n represents 0 or 1, Z**1 represents carbonyl or thiocarbonyl, Y**1 represents unsubstituted or substituted alkylene which may be interrupted by iminocarbonyl or oxycarbonyl, X**3 represents a group of the formula -O- or -N(R**14)-, wherein R**14 has the meaning given above, and A**1 represents a radical of the formula Ib see diagramm : EP0102319,P31,F2 in which R**15 represents an aliphatic or cycloaliphatic radical having at least 7 carbon atoms, or A**1 represents a group of the formula Ic see diagramm : EP0102319,P31,F3 in which R**16 represents hydrogen and R**17 represents 2-hydroxyethyl or 1,2-dihydroxyethyl, wherein at least one hydroxy group is esterified or etherified by a radical having at least 7 carbon atoms, or in which each or R**16 and R**17 independently of the other represents esterified or etherified hydroxymethyl, the esterifying or etherifying radicals having at least 7 carbon atoms, or each of R**1, R**2, R**12 and R**13 independently represents hydrogen, acyl other than a radical of the formula Ia in which n represents 1, or aliphatically substituted silyl, each of R**3, R**4, R**5, R**7 and R**8 independently represents hydrogen or lower alkyl, R**6 represents hydrogen or lower alkyl that is unsubstituted or substituted by a group of the formula Id -E-(Z**2-Y**2-X**4)m -A**2 in which m represents 0 or 1, E represents a group of the formula -O-, -S- or -N(R**14), R**14 having the meaning given above, Z**2 represents carbonyl or thiocarbonyl, Y**2 represents unsubstituted or substituted alkylene which may be interrupted by iminocarbonyl or oxycarbonyl, X**4 represents a group of the formula -O- or -N(R**