Chem. Pharm. Bull., 52(3),311-315, March 2004

Regular Articles

Separation of Stereoisomers of Some Terpene Derivatives by Capillary Gas Chromatography-Mass Spectrometry and High-Performance Liquid Chromatography Using β-Cyclodextrin Derivative Columns

Hiroko F. KASAI,^*,a Masayoshi TSUBUKI,^a Yohichiro MATSUMOTO,^a Mika SHIRAO,^b Kazunori TAKAHASHI,^a Toshio HONDA,^a and Haruhisa UEDA^a

^a Faculty of Pharmaceutical Sciences, Hoshi University; 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan: and ^b Department of Human Nutrition, Jissen Women's Junior College; 1-13-1 Shinmei, Hino, Tokyo 191-0016, Japan. * To whom correspondence should be addressed. e-mail: kasai@hoshi.ac.jp

Gas chromatographic separations of the stereoisomers of menthol derivatives, important intermediates in the synthesis of physiologically active natural products, were carried out on several substituted β-cyclodextrin (CD) columns, including per-O-methyl-β-cyclodextrin (PME-β-CD), heptakis(2,3-di-O-acetyl-6-tert-butyldimethylsilyl)-β-CD (DIAC-6-TBDS-β-CD), and heptakis(2,3-di-O-methyl-6-tert-butyldimethylsilyl)-β-CD (DIME-6-TBDS-β-CD) as chiral stationary phases (CSPs). With the DIME-6-TBDS-β-CD column, a separation of the Z- and E-isomers of methylidenementhol was accomplished; no separation was achieved with the other columns. The stereoisomers of methylidenementhol and the corresponding tert-butyldimethylsilyl (TBS) ether were separated on both the β-CD and the heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TME-β-CD) columns by high-performance liquid chromatography (HPLC) with a mobile phase involving acetonitrile and H₂O. For the separation of the Z- and E-isomers of methylidenementhol, the TME-β-CD column was superior. In contrast, the β-CD column was preferable in the case of the corresponding TBS ether.

Key words stereoisomers separation; β-cyclodextrin derivative; menthol; terpene; GC-MS; HPLC