Synthesis, Characterization, and Retinol Stabilization of Fatty Amide--cyclodextrin Conjugates

Amphiphilic cyclodextrin (CD) has been the object of growing scientific attention because of its two recognition sites, the cavity and the apolar heart, formed by self-assembly. In the present study, mono[6-deoxy-6-(octadecanamido)]--CD and mono[6-deoxy-6-(octadecenamido)]--CD were successfully synthesized by reacting mono-6-amino-6-deoxy--CD with N-hydroxysuccinimide esters of corresponding fatty acids in DMF. The structures were analyzed using nuclear magnetic resonance spectroscopy and mass spectrometry. The amphiphilic -CDs were able to form self-assembled nano-vesicles in water, and the supramolecular architectures were characterized using fluorescence spectroscopy, dynamic light scattering, and transmission electron microscopy. Using the cavity-type nano-vesicles, all-trans-retinol was efficiently encapsulated; it was then stabilized against the photo-degradation. Therefore, the present fatty amide--CD conjugate will be a potential molecule for carrier systems in cosmetic and pharmaceutical applications.