SUPRAMOLECULAR INCLUSION COMPLEXATION OF AMYLOSE WITH PHOTOREACTIVE DYES

A series of 4-[4-(dimethylamino)styryl]-1-alkylpyridinium bromide (DAS P-C(n)) dyes were synthesized for inclusion studies with amylose. Incl usion complexability of DASP dyes with amylose, and conformational tra nsitions of amylose upon complexation with the dyes were investigated using UV-visible, fluorescence, and circular dichroism (CD) spectra in various dimethyl sulfoxide (DMSO)-H2O mixtures. Complete amylose incl usion occurs with DASP dyes > C-12 while it decreases sharply with the dyes less-than-or-equal-to C-12. Amylose inclusion is sensitive to th e solvent composition, showing a clear transition at a DMSO fraction, PHI(DMSO) = 0.6, above which no or negligible complexation occurs. Amy lose resumes the helical conformation upon complexation (at PHI(DMSO) less-than-or-equal-to 0.6) with DASP dyes but the helical state is aff ected by the solvent polarity, becoming loosened with decreasing DMSO content.