L-Theanine an Astounding Amino Acid in Tea, Its Synthesis and Health Benefits: A Review
Urmi Saha, Palak Gupta, Mohipal Singh
International Journal of Biochemistry Research & Review · pp. 21–32 · Published 10 Feb 2024
10.9734/ijbcrr/2024/v33i2855Abstract
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.
References (46)
- 1 Ethanolic Extract of Propolis (EEP) Enhances the Apoptosis- Inducing Potential of TRAIL in Cancer Cells [DOI]
- 2 L‐Theanine: properties, synthesis and isolation from tea [DOI]
- 3 Determination of quality constituents in the young leaves of albino tea cultivars [DOI]
- 4 Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial [DOI]
- 5 L-theanine, a natural constituent in tea, and its effect on mental state.
- 6 An overview of biological production of L-theanine [DOI]
- 7 Theanine transporters identified in tea plants (Camellia sinensis L.) [DOI]
- 8 L-Theanine: A Unique Functional Amino Acid in Tea (Camellia sinensis L.) With Multiple Health Benefits and Food Applications [DOI]
- 9 Effects and mechanisms of tea for the prevention and management of cancers: An updated review [DOI]
- 10 Differential accumulation of specialized metabolite l-theanine in green and albino-induced yellow tea (Camellia sinensis) leaves [DOI]
- 11 Integrated transcriptomics and metabolomics analysis of catechins, caffeine and theanine biosynthesis in tea plant (Camellia sinensis) over the course of seasons [DOI]
- 12 l-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor [DOI]
- 13 Combined analysis of transcriptome and metabolome provides insights into nano-selenium foliar applications to improve summer tea quality (Camellia sinensis) [DOI]
- 14 L-theanine: an astounding sui generis amino acid in poultry nutrition [DOI]
- 15 Exogenous melatonin improves tea quality under moderate high temperatures by increasing epigallocatechin-3-gallate and theanine biosynthesis in Camellia sinensis L. [DOI]
- 16 L-Theanine and Immunity: A Review [DOI]
- 17 Effect of Shading on the Morphological, Physiological, and Biochemical Characteristics as Well as the Transcriptome of Matcha Green Tea [DOI]
- 18 A Novel Theanine Complex, Mg-L-Theanine Improves Sleep Quality via Regulating Brain Electrochemical Activity [DOI]
- 19 L-Theanine Content and Related Gene Expression: Novel Insights into Theanine Biosynthesis and Hydrolysis among Different Tea Plant (Camellia sinensis L.) Tissues and Cultivars [DOI]
- 20 Theanine and Caffeine content of infusions prepared from commercial tea samples [DOI]
- 21 l-Theanine and caffeine improve task switching but not intersensory attention or subjective alertness [DOI]
- 22 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.
- 23 Protective effect of l-theanine on chronic restraint stress-induced cognitive impairments in mice [DOI]
- 24 l-Theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation [DOI]
- 25 l -theanine: A potential multifaceted natural bioactive amide as health supplement [DOI]
- 26 l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion [DOI]
- 27 Inhibition of lung tumor growth by targeting EGFR/VEGFR-Akt/NF-κB pathways with novel theanine derivatives [DOI]
- 28 Perioperative Oral Administration of Cystine and Theanine Enhances Recovery After Distal Gastrectomy [DOI]
- 29 Effects of l -Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study [DOI]
- 30 Oncopreventive effects of theanine and theobromine on dimethylhydrazine-induced colon cancer model [DOI]
- 31 The effect of green tea intake on risk of liver disease: a meta analysis.
- 32 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 [DOI]
- 33 New advances in genetic engineering for l-theanine biosynthesis [DOI]
- 34 l -Theanine alleviates heat stress-induced impairment of immune function by regulating the p38 MAPK signalling pathway in mice [DOI]
- 35 l-Theanine Protects Bladder Function by Suppressing Chronic Sympathetic Hyperactivity in Spontaneously Hypertensive Rat [DOI]
- 36 Theanine, r-glutamylethylamide, increases neurotransmission concentrations and neurotrophin mRNA levels in the brain during lactation [DOI]
- 37 Enzymatic synthesis of theanine from glutamic acid γ-methyl ester and ethylamine by immobilized Escherichia coli cells with γ-glutamyltranspeptidase activity [DOI]
- 38 Health Benefits of Theanine in Green Tea: A Review [DOI]
- 39 l-Theanine promotes cultured human Sertoli cells proliferation and modulates glucose metabolism [DOI]
- 40 Production of L-Theanine Using Escherichia coli Whole-Cell Overexpressing γ-Glutamylmethylamide Synthetase with Baker’s Yeast [DOI]
- 41 Protective effects of a cystine and theanine mixture against acute radiation injury in rats [DOI]
- 42 Enzymatic synthesis of theanine with L-glutamine-Zn(II) complexes [DOI]
- 43 Fermentative Production of L-Theanine in Escherichia coli via the Construction of an Adenosine Triphosphate Regeneration System [DOI]
- 44 Effects of -Cystine and -Theanine Supplementation on the Common Cold: A Randomized, Double-Blind, and Placebo-Controlled Trial [DOI]
- 45 Isolation of L ‐Theanine from Plant Material using a Molecularly Imprinted Polymer [DOI]
- 46 Possible nitric oxide mechanism involved in the protective effect of L-theanine on haloperidol-induced orofacial dyskinesia [DOI]
Cited by 7
Lili Liu, Jingyao Duan, Junhui Yang · Innovative Food Science & Emerging Technologies · 2025
Chengxiu Fu, Zhaoqing Mao, Qing Zhang · 2024
Qiong Wu, Qianqian Zhang, Yating Chen · Italian Journal of Animal Science · 2025
Dinesh Syce · Asian Journal of Medical Sciences · 2025
Showing 4 of 7 known citations — external sources report more than can currently be individually listed.
Related research
- Lipolytic Lactobacillus Species from Camel Milk — shares topic coverage
- Probiotic Products: Appropriate Technologies for Control of Infectious Animal Diseases in the Face of Climate Change and Antimicrobial Resistance — shares topic coverage
- Bioactive Compounds in Fish and Their Health Benefits — shares topic coverage
- A Review on Potential of Some Nigerian Local Food as Source of Functional Food and Their Health Promoting Benefits — shares topic coverage
- Edible Flowers in Herbal Beverage Development — shares topic coverage
Article metrics
Real usage data collected on this platform.
15
Page views
0
PDF downloads
6
Outbound clicks
7
Citations
Views over time
Views by country
Approximate, from request IP at view time — not citizenship or institution. Countries with fewer than 5 views are grouped as "Other".
Traffic sources
Referring site, by host.
Views and downloads exclude known bots/crawlers. Citations combines this platform's own DOI-resolved index with each external source's own reported total — see Cited by above for individually listed citing works. Last refreshed 0 seconds ago.