betadex and 1-2-3-4-tetrahydrocarbazole

The solubilization of four pairs of substituted indole compounds (SICs) by beta-cyclodextrin (beta-CD) in water was investigated. The results show that 1,2,3,4-tetrahydrocarbazole and N-methyl-1,2,3,4-tetrahydrocarbazole form 1:1 inclusion complexes with beta-CD, while the other six SICs form 1:2 inclusion complexes, respectively. To each pair of SICs with similar structures, the differences between their solubilization in beta-CD/water solutions has been explained by the difference of their contact area within the beta-CD cavity, the difference of their molecule polarity, or the presence of hydrogen bond between SIC molecule and beta-CD molecule.

Topics: beta-Cyclodextrins; Carbazoles; Cyclodextrins; Dose-Response Relationship, Drug; Hydrogen Bonding; Indoles; Molecular Structure; Solubility; Water