title: Selectivity enhancement for trans-2-(2,3-anthracenedicarboximido)-cyclohexane-derived diastereomers in HPLC by using an ordered organic stationary phase.
abstract: 2-(2,3-anthracenedicarboximido)cyclohexane derivatives (AC) have been known as the evolutionary diastereomerizing reagents for enantiomer discrimination in HPLC with ODS. However, a substantial separation of diastereomers can be observed only at lower temperatures, such as -40 degrees C. Therefore, in this work, poly(octadecyl acrylate)-grafted silica, ODAn was applied as an alternative stationary phase to ODS for the separation of AC-derived diastereomers. As a result, complete separation was achieved even under the conventional condition: for example, methanol as the mobile phase and 0 degrees C as the column temperature. An investigation on the temperature dependency of the selectivity demonstrated that ODAn shows a remarkable increase in selectivity at temperatures below 30 degrees C, which almost agreed with the peak-top temperature of the endothermic peak in a DSC thermogram for ODA35 immersed in a mobile phase. The better separation would be derived from a highly ordered structure of ODAn and a carbonyl-pi interaction with AC-derived diastereomers.
authors: Department of Applied Chemistry & Biochemistry, Kumamoto University, Japan.
authors: Atsuomi
authors: A
authors: Shundo
authors: Megumi
authors: M
authors: Fukui
authors: Makoto
authors: M
authors: Takafuji
authors: Kazuaki
authors: K
authors: Akasaka
authors: Hiroshi
authors: H
authors: Ohrui
authors: Dusan
authors: D
authors: Berek
authors: Hirotaka
authors: H
authors: Ihara