Semicarbazone-based saponin conjugate

A saponin derivative based on a saponin comprising a triterpene aglycone core structure and at least one of a first saccharide chain ‘R1’ and a second saccharide chain ‘R2’ linked to the aglycone core structure, wherein the saponin derivative comprises an aglycone core structure comprising an aldehyde group, wherein the saponin on which the saponin derivative is based is a or bi-desmosidic triterpene saponin belonging to the type of a 12,13-dehydrooleanane with the aldehyde group in position C-23, and wherein the aldehyde group is transformed into a semicarbazone functional group according to formula (I)

• wherein:
• R1 and R2 are independently selected from a monosaccharide, a linear oligosaccharide, and a branched oligosaccharide,
• X=O, P, or S, and
• Y=NR3R4, wherein R3 and R4 independently represent H, an unsubstituted C1-C10 straight chain, branched or cyclic alkyl, an unsubstituted C2-C10 straight chain, branched or cyclic alkenyl or an unsubstituted C2-C10 straight chain or branched alkynyl, or a covalently bound linker;
• or
• Y=
• wherein n and m each are an integer independently selected from 1, 2, or 3,
• Z=CH2, O, S, P or NR5, and
• wherein R5 represents H, an unsubstituted C1-C10 straight chain, branched or cyclic alkyl, an unsubstituted C2-C10 straight chain, branched or cyclic alkenyl, an unsubstituted C2-C10 straight chain or branched alkynyl, or a covalently bound linker, or a maleimide moiety according to formula (II)a or formula (II)b
• or an azide moiety according to formula (II)c
• wherein o is an integer selected from 0-10, and
• W is a group according to formula (III)
• wherein U=SH, NH2 or OH and
• p is an integer selected from 0-4.