Optical Isomers of Methyl Jasmonate in Tea Aroma.
Two epimers of methyl jasmonate were optically resolved by capillary gas chromatography, using heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin as the chiral stationary phase. In the tea volatile concentrates, both of these epimers were present as only one enantiomer, their absolute configurations being ascertained as (-)-(1R,2R)-methyl jasmonate and (+)-(1R,2S)-methyl epijasmonate. The thermal isomerization of methyl epijamonate to methyl jasmonate was also clarified by optically resolved gas chromatography to have occurred at the asymmetric carbon of the C-2 position that is connected to the carbonyl group.
a Laboratory of Food Chemistry, Department of Nutrition and Food Science , Ochanomizu University , 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112 , Japan.
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Wang
a Laboratory of Food Chemistry, Department of Nutrition and Food Science , Ochanomizu University , 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112 , Japan.
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Kubota
a Laboratory of Food Chemistry, Department of Nutrition and Food Science , Ochanomizu University , 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112 , Japan.
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Kobayashi
chiral separation; methyl epijasmonate; methyl jasmonate; tea aroma formation; thermal isomerization