Comparative study of molecular recognition of folic acid subunits with cyclodextrins.

The complexation of pteroic acid and pterine, subunits of folic acid, with native cyclodextrins (α‒, β‒, and γ‒CDs) was studied in solution (UV-vis), and in the solid state (thermal analysis, IR and Raman). UV-vis titrations at pH = 7.4 provided data regarding stoichiometry of the formed complexes as well as their associations constants.

Comparison of Aqueous and 1-Octanol Solubility as well as Liquid-Liquid Distribution of Acyclovir Derivatives and Their Complexes with Hydroxypropyl-β-Cyclodextrin.

The aim of the presented work is the comparison of aqueous and 1-octanol solubilities of different acyclovir derivatives and their hydroxypropyl-β-cyclodextrin inclusion complexes. The solubility measurements were carried out at different temperatures over the range 25-45 °C using water, 1-octanol, water saturated with 1-octanol, 1-octanol saturated with water, buffered aqueous solutions (pH = 5.5 and 7.

Structural diversity in native cyclodextrins/folic acid complexes--from [2]-rotaxane to exclusion compound.

The formation of different complexes of folic acid depending on the size of the host cyclodextrin resulting in either an exclusion compound (with the smallest α-cyclodextrin) or 2-rotaxane, where cyclodextrin is threaded over folic acid (with β- and γ-cyclodextrins), is presented. The formation is carried out in water which allows both possible application in pharmaceutical sciences and usage of environmentally friendly "green chemistry". The obtained compounds are thoroughly characterized using one and two dimensional NMR, mass spectrometry, differential scanning calorimetry and thermogravimetric analysis.