Syntheses and characterisation of novel cyclodextrin vinyl derivatives from cyclodextrin-nitrophenol-derivatives

In this study novel reactive alpha-, beta- and gamma-cyclodextrin-esters (acrylate, pent-4-enoate and undec-10-enoate) have been synthesised and characterised. The syntheses were carried out by using nitrophenol-esters with the ability to form inclusion complexes with cyclodextrins, thereby aiming at a better control of the substitution degree and number of positional isomers of the cyclodextrin derivatives. Derivatives of alpha-, beta- and gamma-cyclodextrins modified with three different lengths of carbon-chains were successfully synthesised and characterised by MALDI-TOF MS, HPLC and LC-MS/MS, revealing some differences in LC elution patterns, substitution degrees and number of produced positional isomers. Differences were seen as an effect of changing the size of the cyclodextrin as well as the size of the side-chain being attached. The inclusion complexes between the nitrophenol esters and the different cyclodextrins were studied by ITC and selected ones by 2D ROESY NMR, showing some interesting differences in strength and structure of the complexes. These differences are speculated to be the origin of the different substitution patterns of the derivatives as observed by LC-MS/MS.