The present invention relates to a compound represented by formula (I)wherein X is selected from the group of formulae (II) to (IV)whereinR1 is H or C1-C50 chain which may be branched or linear and which may be saturated or unsaturated and which may optionally be interrupted and/or substituted by one or more hetero atom(s) (Het1) and/or functional group(s)(G1) orR1 is a C3-C28 moiety which comprises at least one cyclic structure and which may be saturated or unsaturated and which may optionally be interrupted and/or substituted by one or more hetero atom(s) (Het1) and functional group(s)(G1)R2 is H orR2 is a Mono-phosphate, Di-phosphate, Tri-phosphate or phosphoramidite moiety orR2 is -Y-X or -Y-L-Y1- XY and Y1 are independently from each other a single bond or a functional connecting moiety,X is a colloid-active compound (CA) or a fluorescence marker (FA) or a polynucleotide moiety having up to 50 nucleotide residues, preferably 10 to 25 nucleotides, especially a polynucleotide having an antisense or antigen effectL is a linker by means of which Y and X are covalently linked togetherR3 and R4 represent independently from each other a C1-C28-alkyl moiety which may optionally be substituted or interrupted by one or more heteroatom(s) and/or functional group(s)orR3 and R4 form a ring having at least 5 members, preferably a ring having 5 to 8 carbon atoms and wherein the ring may be substituted or interrupted by one or more hetero atom(s) and/or functional group(s) orR3 and R4 represent independently from each other a C1-C28-alkyl moiety substituted with one or more moieties selected from the group -Y-X or -Y-L-Y1-X orR3 and R4 represent independently from each other -Y-X or -Y-L-Y1- XR5 and R6 represent independently from each other a C1-C28-alkyl moiety which may optionally be substituted or interrupted by one or more heteroatom(s) and/or functional group(s) orR5 and R6 represent independently from each other a C1-C28-alkyl moiety substituted with one or more moietie
