Molecular inclusion complexes: Cyclodextrins and benzaldehyde; cyclodextrins and acetylsalicylic acid

Hee-Sook Choi, Purdue University

Abstract

I. Molecular inclusion complexes of benzaldehyde and selected cyclodextrins. Complexes of cyclodextrins have been studied extensively in recent years with regard to structure, conformation, and use in enzyme modeling. In this research benzaldehyde-cyclodextrin (alpha, beta, permethyl-alpha, and permethyl-beta) inclusion complexes were prepared and analyzed by FT-Infrared, UV, Fast atom bombardment-MS, $\sp1$HNMR and $\sp{13}$CNMR spectroscopy. From the spectral changes observed of the host and guest molecules, orientational preference for binding in the cyclodextrin cavity was determined. A pulse polarographic method was developed for the determination of dissociation constants of the complexes. This method is applicable to many electroactive guest compounds in cyclodextrin complexes whose dissociation constants cannot readily be determined by other analytical methods. Kinetic studies of the autoxidation reaction of selected complexes were also made to determine stability of the host-guest interactions. Each complex studied was assayed in vitro for antitumor activity. The results indicated that the permethyl-alpha-cyclodextrin-benzaldehyde complex was most active. II. Cyclodextrin as a biomimetic enzyme model for the catalytic study of cyclodextrin-aspirin complexes. The molecular nature of aspirin hydrolysis was studied using cyclodextrin as a biomimetic model for esterase. Cyclodextrin was selected for this purpose because it meets the necessary requirements for the hydrolysis study. The structural specificity and the chemical dynamics of these inclusion complexes in the solid state and in the solution state were determined by FT-IR, UV, FAB-MS, $\sp1$HNMR, and $\sp{13}$CNMR spectroscopy. Dissociation constants were obtained by the kinetic method under alkaline conditions.

Degree

Ph.D.

Advisors

Knevel, Purdue University.

Subject Area

Pharmaceuticals

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