Enantiomeric composition of (E)- and (Z)-sabinene hydrate and their acetates in five Origanum spp.

The enantiomers of (E)- and (Z)-sabinene hydrate and of (E)- and (Z)-sabinene hydrate acetate from extracts of Origanum ramonense Danin, O. dayi Post, O. majorana L., O. vulgare L. ssp. vulgare and O. syriacum L. ssp. syriacum were analysed by GC-MS with chiral and non-chiral capillary columns. The order of elution, the enantiomeric ratios and relative percentages of the four pairs of enantiomers were determined. The (1S)-enantiomers of (E)-sabinene hydrate and (E)-sabinene hydrate acetate were predominant in O. dayi, whereas in the other Origanum spp. the (1R)enantiomers were predominant. (Z)-sabinene hydrate acetate was not detected in O. syriacum, while the (1R)-enantiomer was present in an optically pure form in O. ramonense, O. majorana and O. vulgare; in O. dayi the enantiomeric purity was 97%. The enantiomeric distributions of (E)- and (Z)-sabinene hydrate and their acetates were determined for the first time in Origanum spp. Copyright (c) 2004 John Wiley & Sons, Ltd.