Rhodamine-labeled cyclodextrin derivatives

Four different rhodamine-labeled cyclodextrin-based derivatives were synthesized by coupling rhodamine B (Rho B) with β-cyclodextrin (βCD) or rhodamine B isothiocyanate (RBITC) with βCD, randomly (2-hydroxy)propylated βCD (HPβCD) and randomly methylated-βCD (RAMEβ). The introduction of a single amino unit on the primary side of the cyclodextrin scaffolds allowed the coupling of the fluorophore through either a thioureido moiety or a simple amide bond.