Evaluation by 1H-NMR of the effects of cyclodextrin inclusion complexes on the volatility and thermal stability of guest compounds

• Published in: Nippon Nōgeikagaku Kaishi Vol. 67; no. 12; pp. 1713 - 1719
• Main Authors: Okamura, M. (Kyoto Univ., Uji (Japan). Inst. for Chemical Research), Maruyama, T, Wakabayashi, S, Ikushima, K, Okura, I
• Format: Journal Article
• Language: Japanese
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.12.1993; Nippon Nōgei Kagakukai
• Subjects: COMPLEXACION; COMPLEXATION; COMPLEXING; DEXTRINAS; DEXTRINE; DEXTRINS; ESPECTROSCOPIA RMN; METHODE; METHODS; METODOS; NMR SPECTROSCOPY; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; SPECTROSCOPIE RMN; TEMPERATURE RESISTANCE; VOLATILIDAD; VOLATILITE; VOLATILITY
• ISSN: 0002-1407; 1883-6844
• DOI: 10.1271/nogeikagaku1924.67.1713

Cyclodextrin inclusion complexes of volatile materials and unstable compounds are in commercial use in the food industry and elsewhere. Their inclusion properties are usually examined by HPLC and GC, for which samples must first be prepared by dissolution and extraction by solvents. We evaluated the use of high-resolution 1H-NMR for the measurement of guest/host ratios of the inclusion complexes. This method made it possible to estimate the volatility of the compounds incorporated in the complexes and the thermal stability of the complexes. These properties of α- and β- cyclodextrin complexes of pyridine and benzaldehyde were estimated on the basis of changes in the guest/host ratio with storage time and temperature. The relationship between the stability constant of the inclusion complexes and the release properties was not a simple one. β-Cyclodextrin, which has a large space in the molecule, tended to allow an excess of the guest compound to be included, and the oxidation resistance depended on the mode of inclusion.