Theanine/ˈθiːəniːn/, commonly known as L-theanine and sometimes L-gamma-glutamylethylamide or N5-ethyl-L-glutamine, is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine and is found primarily in particular plant and fungal species.[3][4] It was discovered as a constituent of green tea in 1949 and isolated from gyokuro leaves in 1950, thus rendering it a natural product.[5] It constitutes about 1–2% of the dry weight of green tea leaves.[4]
The name theanine without a prefix generally implies the enantiomer, L-theanine, which is the form found in tea leaves from which it is extracted as a powder.[4][6] The right-handed enantiomer, D-theanine, has been comparatively studied less.
Theanine is sold as a dietary supplement and is considered to be safe at doses up to 250 milligrams (mg) by the US Food and Drug Administration.[4][7] It is packaged in gelatin capsules, tablets, and as a powder, and may be an ingredient in branded supplements with caffeine.
The European Food Safety Authority found there was insufficient evidence for a causal relationship between theanine consumption and improved cognitive function, alleviation of psychological stress, maintenance of normal sleep, or reduction of menstrual discomfort.[8]
^ abScheid L, Ellinger S, Alteheld B, Herholz H, Ellinger J, Henn T, et al. (December 2012). "Kinetics of L-theanine uptake and metabolism in healthy participants are comparable after ingestion of L-theanine via capsules and green tea". The Journal of Nutrition. 142 (12): 2091–2096. doi:10.3945/jn.112.166371. PMID 23096008.
^Cite error: The named reference RSC_Chemspider was invoked but never defined (see the help page).
^ abc"L-Theanine". PubChem, US National Library of Medicine. 13 May 2023. Retrieved 16 May 2023.
^ abcd"L-Theanine". Drugs.com. 20 February 2023. Retrieved 16 May 2023.
^"Components of Gyokuro｜ IPPODO". Ippodo-tea.co.jp. Archived from the original on 2015-12-23. Retrieved 2015-05-07.
^Schuster J, Mitchell ES (March 2019). "More than just caffeine: psychopharmacology of methylxanthine interactions with plant-derived phytochemicals". Progress in Neuro-Psychopharmacology & Biological Psychiatry. 89: 263–274. doi:10.1016/j.pnpbp.2018.09.005. PMID 30213684. S2CID 52274913.
^"GRAS notice for L-theanine". US Food and Drug Administration. 5 February 2007. Retrieved 1 May 2023.
^EFSA Panel on Dietetic Products, Nutrition and Allergies, European Food Safety Authority (2011). "Scientific Opinion on the substantiation of health claims related to L-theanine from Camellia sinensis (L.) Kuntze (Tea) and improvement of cognitive function (ID 1104, 1222, 1600, 1601, 1707, 1935, 2004, 2005), alleviation of psychological stress (ID 1598, 1601), maintenance of normal sleep (ID 1222, 1737, 2004) and reduction of menstrual discomfort (ID 1599) pursuant to Article 13(1) of Regulation (EC) No 1924/2006". EFSA Journal. 9 (6): 2238. doi:10.2903/j.efsa.2011.2238.
Theanine /ˈθiːəniːn/, commonly known as L-theanine and sometimes L-gamma-glutamylethylamide or N5-ethyl-L-glutamine, is an amino acid analogue of the proteinogenic...
least 20 days before being harvested. This causes both the amino acid theanine and the alkaloid caffeine in the tea leaves to increase, which yields a...
processing. During shaded growth, the plant Camellia sinensis produces more theanine and caffeine. The powdered form of matcha is consumed differently from...
Phosphatidylserine, Bacopa monnieri, Acetyl-L-carnitine, Uridine monophosphate, L-theanine, Rhodiola rosea, and Pycnogenol which are all forms of dietary supplement...
In enzymology, a theanine hydrolase (EC 3.5.1.65) is an enzyme that catalyzes the chemical reaction N5-ethyl-L-glutamine + H2O ⇌ {\displaystyle \rightleftharpoons...
its high oxalate content (acute oxalate nephropathy). Tea also contains theanine and the stimulant caffeine at about 3% of its dry weight, translating to...
findings have resulted in academic publications. Recent work has focused on theanine and flavonoid antioxidants, both of which occur naturally in tea and are...
Bottled Water Aquafina Aquafina FlavorSplash Driftwell, a water with added L-theanine to encourage sleep. Propel Zero SoBe Lifewater PepsiCo "PepsiCo Annual...
the form of drinks like green tea (where it is present alongside the l-theanine), energy drinks (often containing sugar/sugar-substitutes), or coffee (which...
Kabusecha (冠茶) is sencha grown in the shade to increase amino acids, such as theanine, which contribute to its distinctive flavor. About a week before the tea...
Japan, Russia and Australia, the company is advertising the benefits of theanine, which has psychoactive properties. Lipton still owns plantations in East...
presynaptic EAAT3 (via transporter endocytosis) in dopamine neurons. L-Theanine is reported to competitively inhibit reuptake at EAAT1 (GLAST) and EAAT2...
review and meta-analysis from 2014 found that concurrent caffeine and L-theanine use has synergistic psychoactive effects that promote alertness, attention...
on 3 February 2010. Another advert, promoting the naturally occurring theanine in PG Tips, featured Monkey and Al playing the characters of Captain Mainwaring...
and adhyperforin (both found in Hypericum perforatum St. John's Wort), L-theanine (found in Camellia sinensis, the tea plant), and S-adenosyl-L-methionine...
Farrimond J, Scholey AB (August 2014). "Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood:...
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