Theanine biosynthesis

C-labelled theanine is produced in tea seedlings from labelled glutamic acid (290) or ethylamine (153). Theanine biosynthesis is presumed to take place mainly in the roots (160, 161, 162, 277) but some synthesis also takes place in young buds, stems, and leaves (163). 

The contribution of theanine to the taste of green tea is discussed. Theanine biosynthesis occurs in the plant roots from glutamic acid and ethy-... 

Hatanaka, A., T. Kajiwara and J. Sekiya. Biosynthesis of trans-2-hex-enal in chloroplasts from Thea sinensis. Phytochemistry 1996 15 1125. Matsura, T., T. Tsunoda and M. Arai. Theanine manufacture with tissue cultures of tea. Patent-Japan Kokai Tokkyo Koho-03 187,388 1991 7 pp. Takeo, C., H. Kinugass, H. Oosu, T. Kawasaki, N. Takakuwa, M. Shimizu and H. Kondo. Extraction of hyper-glycemics from tea. Patent-Japan Kokai Tokkyo Koho-04 124,139 1992 8 pp. Stalcup, A. M., K. H. Ekborg, M. P. Gasper and D. W. Armstron. Enantiomeric separation of chiral components reported to be in coffee, tea or... 

Biosynthesis of theanine occurs in the root of the tea plant with the aid of the enzyme theanine synthetase (also called L-glutamate ethylamine ligase or L-glutamate ethyl-amine ligase, EC 6.3.1.6) (figure 16.3). 

Since L-theanine synthetase is quite labile, its further purification may be hampered. There is no report on the purification and property on this enzyme. The biosynthesis of theanine from L-glutamate and ethylamine is shown in the following equation of the L-theanine synthetase catalytic reaction ... 

The biosynthesis route of theanine in tea roots was proposed as shown in figure 16.3. ° "... 

The biosynthesis of theanine from glutamate and ethylamine is catalyzed by theanine synthetase (L-glutamate ethylamine ligase, EC 6.3.1.6), which is an ATP-dependent enzyme and quite unstable. All attempts to biosynthesize theanine using this enzyme should overcome the problems of the ATP generating system. 

Sasaoka, K., Kito, M., and Inagaki, H. 1963. Studies on the biosynthesis of theanine in tea seedlings. Synthesis of theanine by the homogenate of tea seedlings. Agric. Biol. Chem. 27 467-68. 

Sasaoka, K. Biosynthesis of theanine. Nippon Nogei Kagaku Kaishi 39 R1 (1965) (in Japanese). 

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