Cyclodextrin‐Mediated Enantiomeric Separation of Chiral Dihydrofuroflavones, a Class of Compounds with Promising Pharmacological Activity

Abstract

Reversed‐phase high performance liquid chromatography was utilized for the enantioseparation of 16 racemic dihydrofuroflavones. The separations were performed with chiral stationary phases (CSPs) using cyclodextrin‐based chiral selectors. The structural characteristics of the dihydrofuroflavones are discussed in conjunction with the observed enantioselectivity and resolution. Overall, 13 of the 16 dihydrofuroflavone analytes were baseline resolved (Rs > 1.5) on at least one of the cyclodextrin‐based CSPs. The hydroxypropyl‐β‐cyclodextrin (Cyclobond I RSP) phase is the most effective CSP for the enantioseparations of these dihydrofuroflavones. This CSP shows some enantioselectivity for 14 dihydrofuroflavones, and baseline separates 8 of the 16 compounds in the reversed phase mode. The 2,3‐dimethyl‐β‐cyclodextrin CSP also performed well, baseline separating 5 of the 16 analytes in the reversed phase mode. Additionally, the polar organic mode and the normal phase mode were evaluated with native and aromatic derivatized β‐cyclodextrins, but no enantioseparations were observed.

Keywords:

• Chiral stationary phase
• HPLC
• Enantiomer separation
• Cyclodextrin
• Derivatized cyclodextrin
• Dihydrofuroflavones

Acknowledgments

Support of this work by the National Institutes of Health, NIH RO1 GM53825‐06 is gratefully acknowledged. R. V. Rozhkov and R. C. Larock also acknowledge the donors of the Petroleum Research Fund, administered by the American Chemical Society, for partial support of this research and Johnson Matthey Inc. and Kawaken Fine Chemicals Co., for donations of palladium acetate.