L-Theanine an Astounding Amino Acid in Tea, Its Synthesis and Health Benefits: A Review

Urmi Saha *

Tea Board India, Kolkata, 700001, India.

Palak Gupta

Tea Board India, Kolkata, 700001, India.

Mohipal Singh

Tea Board India, Kolkata, 700001, India.

*Author to whom correspondence should be addressed.


Abstract

Tea being a traditional beverage has been consumed for thousands of years becoming a daily habit that facilitates healthy living. Both black and green tea drinking have historically and generally been linked to feelings of refreshment and relaxation. Tea's L-Theanine (L-ʀ- glutamylethylamide), a non-protein amino acid primarily found in tea leaves, is thought to be responsible for this consequence. In addition to improving tea’s flavour, L-Theanine has numerous health benefits. It has a major effect on diseases linked to lifestyle, such as improving vascular function and decreasing risk of cardiovascular diseases. It also has anti- hypertensive, stress reduction, and cancer suppression activity. This amino acid can mitigate the negative effects of neurotoxins, promote normal sleep patterns, and enhance memory.

This review paper aims to explain the chemical and physical properties of L-Theanine, as well as current methods for its synthesis and extraction. It also discusses the factors that influence the theanine content of tea plants and potential health benefits that it could have for humans.

Keywords: Tea, thianine, amino acid, theanine properties, tea plants, health benefits


How to Cite

Saha , Urmi, Palak Gupta, and Mohipal Singh. 2024. “L-Theanine an Astounding Amino Acid in Tea, Its Synthesis and Health Benefits: A Review”. International Journal of Biochemistry Research & Review 33 (2):21-32. https://doi.org/10.9734/ijbcrr/2024/v33i2855.

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References

Adhikary R & Mandal V. L-theanine- a potential multifaceted natural bioactive amide as health supplement. Asian Pac J Trop Bio. 2017;7(9):842–848. Available:https://doi.org/10.1016/j.apjtb.2017.08.005

Baba Y, Inagaki S, Nakagawa S, Kaneko T, Kobayashi M, Takihara T. Effects of l- Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study. Journal of Medicinal Food. 2021;24(4):333–341. Available:https://doi.org/10.1089/jmf.2020.4803

Boros K, Jedlinszki N, Csupor D. Theanine and Caffeine Content of Infusions Prepared from Commercial Tea Samples. Pharmacognosy magazine. 2016;12(45): 75–79. Available:https://doi.org/10.4103/0973-1296.176061

Cao R, Hu S, Lu Y, Wang W, Fu Z, Cheng J. Fermentative Production of L-Theanine in Escherichia coli via the Construction of an Adenosine Triphosphate Regeneration System. Fermentation. 2023;9(10):875. Available:https://doi.org/10.3390/fermentation9100875

Chen S, Kang J, Zhu H, Wang K, Han Z, Wang L, Liu J, Wu Y, He P, Tu Y, Li B. L- Theanine and Immunity: A Review. Molecules (Basel, Switzerland). 2023;28(9):3846. Available:https://doi.org/10.3390/molecules28093846

Chen X, Ye K, Xu Y, Zhao Y, & Zhao D. Effect of Shading on the Morphological, Physiological, and Biochemical Characteristics as Well as the Transcriptome of Matcha Green Tea. International Journal of Molecular Sciences. 2022;23(22):14169. Available:https://doi.org/10.3390/ijms232214169

Cheng S, Fu X, Liao Y, Xu X, Zeng L, Tang J, Li J, Lai J, Yang Z. Differential accumulation of specialized metabolite l-theanine in green and albino-induced yellow tea (Camellia sinensis) leaves. FOOD CHEMISTRY. 2019;276:93–100. Available:https://doi.org/10.1016/j.foodchem.2018.10.010

Choi JH, Ryan LM, Cramer DW, Hornstein MD, &Missmer SA. Effects of Caffeine Consumption by Women and Men on the Outcome of In Vitro Fertilization. Journal of caffeine research. 2011;1(1):29–34. Available:https://doi.org/10.1089/jcr.2011.0001

Dasdelen MF, Er S, Kaplan B, Celik S, Beker MC, Orhan C, Tuzcu M, Sahin N, Mamedova H, Sylla S, Komorowski J, Ojalvo SP, Sahin K, Kilic E. A Novel Theanine Complex, Mg-L-Theanine improves sleep quality via regulating brain electrochemical activity. Frontiers in nutrition. 2022;9:874254. Available:https://doi.org/10.3389/fnut.2022.874254

Deng WW, Ashihara H. Occurrence and de novo biosynthesis of caffeine and theanine in seedlings of tea (Camellia sinensis). Natural product communications. 2015; 10(5), 703–706.

Dias TR, Bernardino RL, Alves MG, Silva J, Barros A, Sousa M, Casal S, Silva BM, & Oliveira PF. L-Theanine promotes cultured human Sertoli cells proliferation and modulates glucose metabolism. European Journal of Nutrition. 2019;58(7):2961–2970. Available:https://doi.org/10.1007/s00394-019-01999-2

Dong C, Li F, Yang T, Feng L, Zhang S, Li F, Li W, Xu G, Bao S, Wan X, Lucas WJ, Zhang Z. Theanine transporters identified in tea plants (Camellia sinensis L.). The Plant Journal: For Cell and Molecular Biology. 2020;101(1), 57–70. Available:https://doi.org/10.1111/tpj.14517

Einöther SJ, Martens VE, Rycroft JA, De Bruin EA. L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness. Appetite. 2010;54(2):406–409. Available:https://doi.org/10.1016/j.appet.2010.01.003

Feng L, Gao MJ, Hou RY, Hu XY, Zhang L, Wan XC, Wei S. Determination of quality constituents in the young leaves of albino tea cultivars. Food Chemistry. 2014;155: 98–104. https://doi.org/10.1016/j.foodchem.2014.01.044

Fiori J, Pasquini B, Caprini C, Orlandini S, Furlanetto S, Gotti R. Chiral analysis of theanine and catechin in characterization of green tea by cyclodextrin-modified micellar electrokinetic chromatography and high performance liquid chromatography. Journal of chromatography. A, 2018;1562:115–122. Available:https://doi.org/10.1016/j.chroma.2018.05.

Gong AD, Lian SB, Wu NN, Zhou YJ, Zhao SQ, Zhang LM, Cheng L, & Yuan HY. Integrated transcriptomics and metabolomics analysis of catechins, caffeine and theanine biosynthesis in tea plant (Camellia sinensis) over the course of seasons. BMC plant biology, 2020; 20(1), 294. https://doi.org/10.1186/s12870-020- 02443-y

Hidese S, Ogawa S, Ota M, Ishida I, Yasukawa Z, Ozeki M., Kunugi H. Effects of L- Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019;11(10):2362. Available:https://doi.org/10.3390/nu11102362

Hidese S, Ota M, Wakabayashi C, Noda T, Ozawa H, Okubo T, Kunugi H. Effects of chronic l-theanine administration in patients with major depressive disorder: an open- label study. Acta neuropsychiatrica. 2017;29(2):72–79. Available:https://doi.org/10.1017/neu.2016.33

Hu Y, Lin L, Liu K, Liu e, Han S, Gong Z, Xiao W. l-Theanine alleviates heat stress- induced impairment of immune function by regulating the p38 MAPK signalling pathway in mice†. Food Funct. 2023;14(1): 335-343. Available:https://doi.org/10.1039/D2FO02775E

Huang X, Tang Q, Chen C, Li Q, Lin H, Bai S, Zhao J, Li J, Wang K, Zhu M. Combined analysis of transcriptome and metabolome provides insights into nano- selenium foliar applications to improve summer tea quality (Camellia sinensis). Science Direct. 2023; 175(8):114496

Jiang HB. Diversity of tea landraces based on agronomic and quality traits in yunnan province. J. Plant Genet. Res. 2013;14 634–640

Kurihara S, Hiraoka T, Akutsu M, Sukegawa E, Bannai M, Shibahara S. Effects of (L)-cystine and (L)-theanine supplementation on the common cold: a randomized, double-blind, and placebo-controlled trial. Journal of amino acids. 2010; 307475. https://doi.org/10.4061/2010/307475

Lachova M, Lehotay J, Karasova G, SkacaniI.Isolation of L‐ Theanine from plant material using a molecularly imprinted polymer. Journal of Liquid Chromatography & Related Technologies. 2007;30(13-16): 2045-2058. Available:https://doi.org/10.1080/10826070701435053

Li MY, Liu HY, Wu DT, Kenaan A, Geng F, Li HB, Gunaratne A, Li H, Gan RY. L- Theanine: A unique functional amino acid in tea (Camellia sinensis L.) with multiple health benefits and food applications. Frontiers in Nutrition. 2022;9:853846. Available:https://doi.org/10.3389/fnut.2022.853846

Li X, Li MH, Deng WW, Ahammed GJ, Wei JP, Yan P, Zhang L P, Fu J Y, Han WY. Exogenous melatonin improves tea quality under moderate high temperatures by increasing epigallocatechin-3-gallate and theanine biosynthesis in Camellia sinensis L. Journal of plant physiology. 2020;253:153273. Available:https://doi.org/10.1016/j.jplph.2020.153273

Li Z, Zhu R, Liu Y, Li J, Gao H, Hu N. γ-Glutamyltranspeptidase from Bacillus amyloliquefaciens: transpeptidation activity enhancement and L-theanine production. Enzyme and Microbial Technology. 2020;140:109644.

Liu ZW, Wu ZJ, Li H, Wang YX, Zhuang J. L-theanine content and related gene expression: novel insights into theanine biosynthesis and hydrolysis among different tea plant (Camellia sinensis L.) tissues and cultivars. Front Plant Sci. 2017;8:498. DOI: 10.3389/fpls.2017.00498

Liang Y R, Liu C, Xiang LP and Zheng XQ. Health Benefits of Theanine in Green Tea: A Review. Tropical Journal of Pharmaceutical Research. 2015;14(10): 1943- 1949

Liu S, Li J, Huang J, Liu Z, Xiong L. New advances in genetic engineering for l- theanine biosynthesis, Trends in Food Science & Technology. 2021; 114, 540-551

Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Alternative medicine review : a journal of clinical therapeutic. 2011; 16(4), 348–354.

Matsuoka K, Akaihata H, Hata J, Tanji R, Honda-Takinami R, Onagi A, Hoshi S, Koguchi T, Sato Y, Kataoka M, Ogawa S, Kojima Y. l-Theanine Protects Bladder Function by Suppressing Chronic Sympathetic Hyperactivity in Spontaneously Hypertensive Rat. Metabolites. 2021;11(11):778. Available:https://doi.org/10.3390/metabo11110778

Matsuu-Matsuyama M, Shichijo K, Tsuchiya T, Kondo H, Miura S, Matsuda K, Sekine I, Nakashima M. Protective effects of a cystine and theanine mixture against acute radiation injury in rats. Environmental Toxicology and Pharmacology. 2020;78:103395. Available:https://doi.org/10.1016/j.etap.2020.103395

Miyachi T, Tsuchiya T, Oyama A, Tsuchiya T, Abe N, Sato A, Chiba Y, Kurihara S, Shibakusa T, Mikami T.Perioperative oral administration of cystine and theanine enhances recovery after distal gastrectomy: A prospective randomized trial. Journal of parenteral and enteral nutrition. 2013; 37(3):384–391.Available:https://doi.org/10.1177/0148607112458798

Mu W, Zhang T, Jiang B.An overview of biological production of L-theanine. Biotechnology Advances. 2015;33(3–4):335-342

Narukawa M, Toda Y, Nakagita T, Hayashi Y, Misaka T. L-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor. Amino Acids. 2014;46(6):1583–1587. Available:https://doi.org/10.1007/s00726-014-1713-3

National Center for Biotechnology Information (2023). PubChem Compound Summary for CID 439378, Theanine; 2023. Available:https://pubchem.ncbi.nlm.nih.gov/compound/Theanine.

Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific journal of clinical nutrition. 2008;17:167–168.

Ota M, Wakabayashi C, Sato N, Hori H, Hattori K, Teraishi T, Ozawa H, Okubo T, Kunugi H. Effect of L-theanine on glutamatergic function in patients with schizophrenia. Actaneuropsychiatrica. 2015;27(5):291–296. Available:https://doi.org/10.1017/neu.2015.22

Pan X, Yu J, Du Q, Zeng S, Liu J, Jiao Q, Zhang H. Efficient synthesis of γ-glutamyl compounds by co-expression of γ-glutamylmethylamide synthetase and polyphosphate kinase in engineered Escherichia coli. Journal of Industrial Microbiology & Biotechnology: Official Journal of the Society for Industrial Microbiology and Biotechnology. 2020;47(8):573-583.

Saeed M, Khan MS, Kamboh AA, Alagawany M, Khafaga AF, Noreldin AE, Qumar M, Safdar M, Hussain M, Abd El-Hack ME, Chao S. L-theanine: An astounding sui generis amino acid in poultry nutrition. Poultry Science. 2020;99 (11):5625–5636. Available:https://doi.org/10.1016/j.psj.2020.07.016

Shojaei-Zarghani S, Yari Khosroushahi A, Rafraf M. Oncopreventive effects of theanine and theobromine on dimethylhydrazine-induced colon cancer model. Biomedicine & pharmacotherapy = Biomedecine&pharmacotherapie. 2021;134;111140. Available:https://doi.org/10.1016/j.biopha.2020.111140

Siamwala JH, Dias PM, Majumder S, Joshi MK, Sinkar VP, Banerjee G, Chatterjee S. L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation. The Journal of nutritional biochemistry. 2013;24(3):595–605. Available:https://doi.org/10.1016/j.jnutbio.2012.02.016

Souparnika V, Karthik Ganesh Mohanraj, Vidya S. Antioxidant Activity OfL - Theanine On Cadmium Induced Oxidative Stress Mediated Neurodegeneration -An In Vivo Analysis.Therapeutics and Clinical Pharmacology. 2023;29(02):123–130.

Tian X, Sun L, Gou L, Ling X, Feng Y. Wang L, Yin X, Liu Y. Protective effect of l- theanine on chronic restraint stress-induced cognitive impairments in mice. Brain Research. 2013; 1503, 24–32. Available:https://doi.org/10.1016/j.brainres.2013.01.048

Tsai CC, Wang MH, Chang KC, Soung HS, Yang CC, Tseng HC.Possible nitric oxide mechanism involved in the protective effect of L-theanine on haloperidol-induced orofacial dyskinesia. The Chinese journal of physiology. 2019;62(1):17–26. Available:https://doi.org/10.4103/CJP.CJP_8_19

Tsai WH, Wu CH, Yu HJ, Chien CT. l-Theanine inhibits proinflammatory PKC/ERK/ICAM-1/IL-33 signaling, apoptosis, and autophagy formation in substance P-induced hyperactive bladder in rats. Neurourology and Urodynamics. 2017;36(2):297–307. Available:https://doi.org/10.1002/nau.22965

Unno K. Prevention of brain aging by green tea components: Role of catechins and theanine, The Journal of Physical Fitness and Sports Medicine. 2016;5(2): 117-122. Available:https://doi.org/10.7600/jpfsm.5.117

Vuong QV, Bowyer MC, Roach PD. L-Theanine: Properties, synthesis and isolation from tea. Journal of the Science of Food and Agriculture. 2011;91(11): 1931–1939. Available:https://doi.org/10.1002/jsfa.4373

Wang HQ, Yao Z, Zhou Z,Sun Y, Wei P, Ouyang P. Enzymatic synthesis of theanine with L-glutamine-Zn (II) complexes.Biotechnology and Bioprocess Engineering. 2012;17:1135–1139. Available:https://doi.org/10.1007/s12257-012-0205-0

Wanga L, Brennanb M, Lic S, Zhaod H, LangeeK, Brennanb C. How does the tea L- theanine buffer stress and anixity. Food Science and Human Wellness. 2022; 11(3) 467-475

Williams J, Kellett J, Roach P, McKune A, Mellor D, Thomas J, Naumovski N. l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. Beverages. 2016;2(2): 13.Available:https://doi.org/10.3390/beverages2020013

Xu XY, Zhao CN, Cao SY, Tang GY, Gan R. Y, Li HB. Effects and mechanisms of tea for the prevention and management of cancers: An updated review. Critical reviews in Food Science and Nutrition. 2020;60(10):1693–1705. Available:https://doi.org/10.1080/10408398.2019.1588223

Yamada T, Terashima T, Wada K, Ueda S, Ito M., Okubo T, Juneja LR., Yokogoshi H. Theanine, r-glutamylethylamide, increases neurotransmission concentrations and neurotrophin mRNA levels in the brain during lactation. Life Sciences. 2007;81(16):1247–1255. Available:https://doi.org/10.1016/j.lfs.2007.08.023

Yang SY, Han YH, Park YL, Park JY, No SY, Jeong D, Park S, Park HY, Kim W, Seo SO, Yang YH. Production of L-Theanine Using Escherichia coli Whole-Cell Overexpressing γ-Glutamylmethylamide Synthetase with Baker’s Yeast, J. Microbiol. Biotechnol. 2020;30(5): 785–792. Available:https://doi.org/10.4014/jmb.1910.10044

Yin X, Yang J, Li T, Song L, Han T, Yang M, Liao H, He J, Zhong X. The effect of green tea intake on risk of liver disease: a meta analysis. International Journal of Clinical and Experimental Medicine. 2015; 8(6):8339–8346.

Yoneda J, Nishikawa S, Kurihara S. Oral administration of cystine and theanine attenuates 5-fluorouracil-induced intestinal mucositis and diarrhea by suppressing both glutathione level decrease and ROS production in the small intestine of mucositis mouse model. BMC Cancer. 2021;21(1):1343. Available:https://doi.org/10.1186/s12885-021- 09057-z

Zhang F, Zheng QZ, Jiao QC, Liu JZ, Zhao GH. Enzymatic synthesis of theanine from glutamic acid γ-methyl ester and ethylamine by immobilized Escherichia coli cells with γ-glutamyltranspeptidase activity. Amino Acids. 2010;39(5):1177–1182. Available:https://doi.org/10.1007/s00726-010-0553-z

Zhang G, Ye X, Ji D, Zhang H, Sun F, Shang C, Zhang Y, Wu E, Wang F, Wu F, Tian H, Liu X, Chen L, Liu K, Wang Y, Liu H, Zhang W, Guan Y, Wang Q, Zhao X, Wan X. Inhibition of lung tumor growth by targeting EGFR/VEGFR-Akt/NF -κB pathways with novel theanine derivatives. Oncotarget. 2014;5(18):8528–8543. Available:https://doi.org/10.18632/oncotarget.2336

Zhang R, Zheng L, Zhou L, Xiang L, Jiang B, Zhang T, Chen J. Characterization of alkaline Bacillus amyloliquefaciens γ-glutamyltranspeptidase expressed in Bacillus subtilis and its application in enzymatic synthesis of L-Theanine. Process Biochem. 2023;131:125–132.