Preparation and self-inclusion properties of p-xylylenediamine-modified beta-cyclodextrins: dependence on the side of modification

Abstract

beta -Cyclodextrin (beta -CDx) derivatives modified with p-xylylenediamine at the 3-position, mono-3-deoxy-3-[4-(aminomethyl)benzylamino]-beta -CDx (1; beta -CDx-3-p-xylylenediamine) was prepared by the reaction of beta -CDx-2,3-manno-epoxide with p-xylylenediamine. The circular dichroism properties of 1 are compared with those of the corresponding beta -CDx derivative modified at the primary side (2; beta -CDx-6-p-xylylenediamine), in the presence and in the absence of 1-adamantanamine . HCl. The results indicate that the xylylenediamine group of 2 is self-included in the beta -CDx cavity, whereas that of 1 stays outside the cavity. The energy obtained by molecular modeling showed the same trend. The dependence of self-inclusion behavior of a pendant group in modified cyclodextrins on the position of modification could be a useful guide for designing cyclodextrin derivatives for various applications.