Compounds of formula: wherein: (i) X denotes -O-, -S-, or substituted or unsubstituted -CH 2 -, Y and Z denote in each case, independently of one another, -O-, -NH-, -S-, substituted or unsubstituted -CH 2 - or a direct bond to R 1 and/or R 2; (ii) a) R 1 denotes hydrogen, linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring, and R 2 denotes linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring; or b) R 1 comprises, preferably is, a substituted or non-substituted (C 1 -C 5 alkyl)aryl group and R 2 is hydrogen; or c) R 2 is a linear or branched, substituted or non-substituted C 1 -C 7 alkyl, C 2 -C 7 alkenyl, alkynyl, or alkylidene, C 3 -C 7 cycloalkyl, C 3 -C 7 aryl, preferably aralkyl, C 3 -C 7 heteroaryl or C 3 -C 7 heterocyclic and R 1 is hydrogen; (iii) R 3 and R 4 denote in each case, independently of one another, hydrogen, amino or hydroxyl; (iv) R 5 denotes a mono-, di- or trisaccharide, preferably a mono- or disaccharide, more preferably a disaccharide, especially preferred 2,6-diamino-2,6-dideoxy-β-L-idopyranosyl-(1→3)-β-D-ribofuranosyl moiety; and (v) R 6 denotes hydrogen; and their diastereoisomers or enantiomers in the form of their bases or salts of physiologically compatible acids for use in the treatment and/or prevention of a microbial infection, preferably a bacterial infection, trypanosomiasis or leishmaniasis, wherein the compounds of formula are not compounds of formula: wherein R is selected from the group consisting of N(CH 3) 2, N (CH 2) 3 NH 2, N N -BOC, N CH 3, N (CH 2) 4 NH 2, N C (CH 3) 2, N NH 2, N (CH 2) 2 Ph, N(CH 3)(CH 2) 2 Ph, N (CH 2) 3 Ph, N C (CH 3)CH 2 Ph, N(CH 3)C (CH 2)Ph, (i) X denotes -O-, -S-, or substituted or unsubstituted -CH 2 -, Y and Z denote in each case, independently of one another, -O-, -NH-, -S-, substituted or unsubstituted -CH 2 - or a direct bond to R 1 and/or R 2; (ii) a) R 1 denotes hydrogen, linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring, and R 2 denotes linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring; or b) R 1 comprises, preferably is, a substituted or non-substituted (C 1 -C 5 alkyl)aryl group and R 2 is hydrogen; or c) R 2 is a linear or branched, substituted or non-substituted C 1 -C 7 alkyl, C 2 -C 7 alkenyl, alkynyl, or alkylidene, C 3 -C 7 cycloalkyl, C 3 -C 7 aryl, preferably aralkyl, C 3 -C 7 heteroaryl or C 3 -C 7 heterocyclic and R 1 is hydrogen; a) R 1 denotes hydrogen, linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring, and R 2 denotes linear or branched, substituted or non-substituted alkyl, alkenyl, alkynyl, alkylidene, carbocycle or YR 1 and ZR 2 together form a substituted or non-substituted cycloalkyl or a corresponding heterocyclic ring; or b) R 1 comprises, preferably is, a substituted or non-substituted (C 1 -C 5 alkyl)aryl group and R 2 is hydrogen; or c) R 2 is a linear or branched, substituted or non-substituted C 1 -C 7 alkyl, C 2 -C 7 alkenyl, alkynyl, or alkylidene, C 3 -C 7 cycloalkyl, C 3 -C 7 aryl, preferably aralkyl, C 3 -C 7 heteroaryl or C 3 -C 7 heterocyclic and R 1 is hydrogen; (iii) R 3 and R 4 denote in each case, independently of one another, hydrogen, amino or hydroxyl; (iv) R 5 denotes a mono-, di- or trisaccharide, preferably a mono- or disaccharide, more preferably a disaccharide, especially preferred 2,6-diamino-2,6-dideoxy-β-L-idopyranosyl-(1→3)-β-D-ribofuranosyl moiety; and (v) R 6 denotes hydrogen; and their diastereoisomers or enantiomers in the form of their bases or salts of physiologically compatible acids for use in the treatment and/or prevention of a microbial infection, preferably a bacterial infection, trypanosomiasis or leishmaniasis, wherein the compounds of formula are not compounds of formula: wherein R is selected from the group consisting of N(CH 3) 2, N (CH 2) 3 NH 2, N N -BOC, N CH 3, N (CH 2) 4 NH 2, N C (CH 3) 2, N NH 2, N (CH 2) 2 Ph, N(CH 3)(CH 2) 2 Ph, N (CH 2) 3 Ph, N C (CH 3)CH 2 Ph, N(CH 3)C (CH 2)Ph,