Synthesis Of Several β-Cyclodextrin Derivatives And Their Complexations With Some Drug Molecules

Cyclodextrins and their derivatives can selectively bind guest molecules to formcomplexes with their hydrophobic cavities. In this way, many properties of the guestcompounds are greatly improved such as solubility and stability. So cyclodextrinshave been widely used in the studies of food, pharmaceutics, environmental scienceand sanitation, etc.In this paper, four β-cyclodextrin derivatives were synthesized, they aremono-2-hydroxypropyl-β-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroethyl-β-cyclodextrin and methylated-β-cyclodextrin. The four derivatives were characterizedby TLC, DSC and FTIR. Benzoic acid, p-aminobenzoic acid, aspirin,methyltestostrone, vitamin D2 were used as guest compounds to study molecularrecognition properties of the system, the host-guest complexes were prepared andcharacterized by DSC and FTIR, and their stability constants were calculated. Theresults show that the complexes are different from their physical mixturescounterparts. The solubility of these complexes is greater than pure guest compounds.Except vitamin D2, the complexes formed with mono-2-hydorxypropyl-β-cyclodextrin are more stable than that of the β-cyclodextrin. As the molar ratios ofthese host-guest complexes were 1:1for benzoic acid, 1:1 for p-aminobenzoic acid,1:1 for a spirin, 1.7:1 for methyltestostrone, and 2:1for vitamin D2, their complexmodels could thus be deduced from these ratios as well as their IR spectrum.