| abstract |
Compounds of the formula <IMAGE> in which R1 represents an optionally substituted, straight-chain or branched, saturated, monounsaturated or polyunsaturated alkyl radical, an optionally substituted, saturated or one- or polyunsaturated cycloalkyl radical or an optionally substituted aryl radical or aralkyl radical, X represents CH2, O, S, NH or N-alkyl with up to 20 C atoms, R2 has the meaning of R1, and can represent hydrogen if X denotes CH2, the radicals R3 independently of one another represent hydrogen, an acyl radical or alkyl radical with in each case up to 20 C atoms, a silyl radical and/or a phosphoric acid or phosphoric acid ester radical and R4 denotes hydrogen, methyl or -CH2-OR3, with the proviso that one of the radicals R3 always represents a phosphoric acid or phosphoric acid ester radical, which stimulate a patient's immune system and are thereby effective in combating viral disease and bacterial infection. |