Studies on the Chemical Constituents of Tea
Open accessAbstract
The author discovered a new amide in the water extract of Japanese green tea, and named it “theanine”. This substance crystallizes in the form of colorless needle; molecular formula C7H14O3N2, melting point 217_??_218° (decompose), and [α]12 D=+7.1. It presents strong ninhydrin reaction. It is very soluble in water, and is dissolved in 2.6 times of water at 0° and 1.8 times of water at 100°, but insoluble in ethyl alcohol and ether. By hydrolysis of theanine, it gives L-glutamic acid and ethyl amine nearly quantitatively. From the fact that it shows no biuret reaction and that the natural glutamine is γ-amide, it seems very probable that theanine may be L-glutamic acid γ-ethyl amide. It is the first time that ethyl amine has been discovered, though not in a free state, in plant kingdom. The author has also studied the distribution of theanine in each stage of tea leaf developments. Gyokuro is rich (about 1%) in it, but Sencha is poor. It seems, therefore, that theanine assumes the analogous rôle of glutamine or asparagine in other plants though the destination of ethyl amine is yet unknown.
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l-Theanine has been shown as an emerging option for stress management.
“l-Theanine is a water-soluble, non-protein amino acid predominantly found in green tea leaves that has been shown as an emerging option for stress management [6].”
l-Theanine is a water-soluble, non-protein amino acid predominantly found in green tea leaves.
“l-Theanine is a water-soluble, non-protein amino acid predominantly found in green tea leaves that has been shown as an emerging option for stress management [6].”
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- Authors
- SAKATO, Y.
- Venue
- Journal of the agricultural chemical society of Japan
- Published
- 1950
- Volume
- 23
- Issue
- 6
- Pages
- 262-267
- ISSN
- 0002-1407 (ISSN-L)
- 1883-6844
- OpenAlex
- W2323839409
- Cited by
- 148
- References
- 0
- Citations by year
- 2026: 2 · 2025: 9 · 2024: 4 · 2023: 3 · 2022: 6 · 2021: 11 · 2020: 3 · 2019: 11 · 2018: 5 · 2017: 3 · 2016: 3 · 2015: 4 · 2014: 7 · 2013: 6 · 2012: 8
- FWCI
- 0.00
- Type
- journal article
- Language
- ja
- Open access
- diamond
- doi.org
- Locations
- Nippon Nōgeikagaku Kaishi (publishedVersion)
- Topics
- Health Sciences › Medicine › Pathology and Forensic Medicine › Tea Polyphenols and Effects
- Life Sciences › Agricultural and Biological Sciences › Food Science › Food and Agricultural Sciences
- Physical Sciences › Chemistry › Analytical Chemistry › Heavy Metals in Plants
- Keywords
- theanine, green tea, Japanese green tea, amides, glutamate, ethylamine, glutamine, asparagine, sencha, ninhydrin reaction, hydrolysis
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