Miharu Ogura

Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

Oriental Beauty, which is made from tea leaves infested by the tea green leafhopper (Jacobiasca formosana) in Taiwan, has a unique aroma like ripe fruits and honey. To determine what occurs in the tea leaves during the oolong tea manufacturing process, the gene expression profiles and the chemical profiles were investigated. Tea samples were prepared from Camellia sinensis var. sinensis cv. Chin-shin Dah-pang while the tea leaves were attacked by the insect. The main volatile compounds, such as linalool-oxides, benzyl alcohol, 2-phenylethanol, and 2,6-dimethylocta-3,7-diene-2,6-diol, increased during manufacture. The gene expression profiles during manufacture were analyzed by differential screening between fresh leaves and tea leaves of the first turn over. Many up-regulated transcripts were found to encode various proteins homologous to stress response proteins. Accordingly, the endogenous contents of abscisic acid and raffinose increased during manufacture. Thus the traditional manufacturing method is a unique process that utilizes plant defense responses to elevate the production of volatile compounds and other metabolites.

Synthesis and odor of optically active 2-n-hexyl- and 2-n-heptylcyclopentanone and the corresponding δ-lactones

Enantiomeric 2-n-hexyl- and 2-n-heptylcyclopentanones (3) and (4) have been synthesized by asymmetric hydrogenation of 2-n-hexylidene and 2-n-heptylidenecyclopentanones (1) and (2) with Ru2Cl4[p-tolyl-binap]2NEt3 complexes. The differences in odor qualities between enantiomeric pairs of the ketones 3 and 4 have been found to be small, and the same odor threshold values have been observed between the enantiomeric pairs, although the corresponding δ-undeca- and δ-dodecalactones (6) and (7), synthesized by Baeyer–Villiger oxidation of the chiral ketones 3 and 4, showed a fairly large difference in the threshold values between the enantiomeric pairs.

A novel synthetic method for (R)- and (S)-muscones by enantioselective hydrogenation of (E)- and (Z)-3-methyl-2-cyclopentadecen-1-ones catalyzed by p-tolyl-BINAP-Ru(II) complexes

A novel and practical synthesis of (R)- and (S)-muscones by the asymmetric hydrogenation of (E)- and (Z)-3-methyl-2-cyclopentadecen-1-ones catalyzed by p-tolyl-BINAP-Ru(II) complexes has been achieved in nearly complete enantioselectivity.