RSC Advances
·
2022
·Vol. 12
·期 33
·21135-21144
·
IF 4.036
Yirong Xia,Wei Ni,Xintong Wang,Yanyan Wang,Ximing Huang
The health benefits of drinking tea stem from it being rich in polyphenols and other physiologically-active substances. Thus, exploring the synergistic effect between polyphenols and a variety of physiologically-active substances can contribute to our understanding of how tea benefits health. In this work, we have studied the interactions between catechin and theanine, exploring the synergetic antioxidant mechanism of the two molecules. Electrochemical characterization results showed that the oxidation peak current of catechin decreased gradually with the concentration of theanine, which is due to theanine spontaneously binding to catechin through intermolecular hydrogen bonds and forming molecular clusters via two hydrogen bonds. The binding constant is 4.75 at room temperature. The molecular clusters reduce the diffusion coefficient of catechin in solution, leading to the slow release of its antioxidant capacity (ability to effectively inhibit free radical oxidation reactions). Density functional theory calculations were also performed and verified the binding behavior. In identifying the synergistic effect between catechin and theanine on the antioxidant capacity of tea, this study adds to our understanding of the efficacy of tea polyphenols.
研究领域:
食品科学
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生物化学
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DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2020
·
IF 4.006
Mingming Zhang,Yanqin Yang,Haibo Yuan,Jinjie Hua,Yuliang Deng,Yongwen Jiang,Jinjin Wang
In this study, a combination of quantitative drying and Maillard reaction was investigated by addition of theanine and sucrose during the final firing process to explore the mechanism of chestnut-like aroma formation. The influence of exogenous additives on the formation of chestnut-like flavor of green tea was characterized by infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), physicochemical components as well as sensory evaluation. The addition of theanine or sucrose separately could improve the chestnut-like characteristics flavor, among which the chestnut-like aroma quality and comprehensive quality of green tea was significantly improved by the addition of theanine/dry tea (5‰ w/w). Significant difference ( p < 0.05 ) was observed among different addition treatments on physicochemical components. In addition, the effect of different drying time (15–75 min) was investigated and the chestnuts-like aroma was significantly improved when the drying time reached 45 min. Moreover, the change trends of two key chestnut-like aroma compounds (methyl salicylate and α-ionone) were well consistent with the sensory evaluation and reached the highest at 45 min. The results would further enrich the basic theoretical system of chestnut-like fragrance and also provide a reference for the processing of chestnut-like aroma of green tea.
研究领域:
食品科学
·
茶叶加工学
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DOI
高影响因子
Foods
·
2025
·Vol. 14
·期 2
·221
·
IF 5.1
Zhihang Huang,Haiming Jing,Yan Pan,Hongxia Cai,Wenjing Zhang,Jingyuan Zhu,Nan Zhang,Dan Wu,Wentao Xu,Hexiang Qiu,Huihui Bao,Guojun Li,Junyu Ning,Bo Xian,Shan Gao
L-theanine, a non-protein amino acid naturally occurring in tea leaves, is recognized for its antioxidant, anti-inflammatory, and neuroprotective properties. Despite its known benefits, the mechanisms by which L-theanine influences lifespan extension remain poorly understood. This study investigated the effects of L-theanine on the lifespan ofCaenorhabditis elegansand explored the underlying mechanisms. Our findings indicate that L-theanine significantly diminishes the accumulation of advanced glycation end products (AGEs), which are biomarkers closely linked to aging and age-related diseases. Through an AGE-level analysis, we observed that L-theanine, when administered during early adulthood, notably extended the lifespan ofCaenorhabditis elegansunder both normal and high-glucose-induced stress conditions. L-theanine enhanced the lifespan under typical conditions and provided protective effects against high-glucose-induced stress. A further analysis demonstrated that L-theanine extends the lifespan ofCaenorhabditis elegansby modulating the DAF-2/DAF-16 insulin-like signaling pathway and reducing the accumulation of advanced glycation end products (AGEs). In summary, this study identified L-theanine as a potential anti-aging intervention that extends the lifespan by reducing AGE accumulation and regulating insulin-like signaling pathways. These findings provide new insights for developing anti-aging strategies and lay the groundwork for further research on the potential benefits of L-theanine in mammals. Future studies could explore the molecular mechanisms, test L-theanine in mammalian models, and assess the long-term side effects.
研究领域:
生物化学
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衰老研究
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分子生物学
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2015
·
IF 3.545
Fengling Zhu,Jing Wang,Lijun Zhu,Lanlan Tan,Guanglin Feng,Shaomin Liu,Ya Dai,Hua Wang
In this paper, a novel dummy template molecularly imprinted polymer (DMIP) based on a vinyl-SiO 2 microspheres surface for the simultaneous selective recognition and enrichment of 18 amino acids was prepared via a surface molecular imprinting technique using theanine as a dummy template. Compared to the imprinted polymers prepared using traditional polymerization techniques, the obtained DMIPs exhibited a regular spherical shape and were relatively monodisperse. The maximal sorption capacity ( Q max ) of the resulting DMIPs for the 18 amino acids was up to 1444.3 mg g −1 . A kinetic binding study showed that the sorption capacity reached 85.40% of Q max in 25 min and sorption equilibrium at 30 min. The imprint factors of the sorbents ranged from 2.86 to 6.9 for the 18 amino acids, which indicated that the DMIP sorbents have high selectivity. An HPLC-UV method for the simultaneous determination of 18 amino acids in tobacco and tobacco smoke was developed using the DMIPs as sorbents for solid phase extraction (SPE) in the sample pretreatment procedure. Under the optimum experimental conditions, the materials had enrichment factors of up to 200 for the amino acids, and the recoveries of the 18 amino acids in tobacco smoke were in the range from 79% to 104% with relative standard deviations of less than 7.4%. It indicated that the obtained DMIP sorbents could specifically recognize the amino acids from complicated samples.
研究领域:
分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
Biotechnology for Biofuels and Bioproducts
·
2023
·Vol. 16
·期 1
·1-13
·
IF 0
Gao Hui,Li Mengxuan,Wang Qing,Liu Tingting,Zhang Xian,Yang Taowei,Xu Meijuan,Rao Zhiming
ATP, an important cofactor, is involved in many biocatalytic reactions that require energy. Polyphosphate kinases (PPK) can provide energy for ATP-consuming reactions due to their cheap and readily available substrate polyphosphate. We determined the catalytic properties of PPK from different sources and found that PPK from Cytophaga hutchinsonii ( Ch PPK) had the best catalytic activity for the substrates ADP and polyP 6 . An extracellular–intracellular dual system was constructed to high-throughput screen for better catalytic activity of Ch PPK mutants. Finally, the specific activity of Ch PPK D82N-K103E mutant was increased by 4.3 times. Therefore, we focused on the production of L-theanine catalyzed by GMAS as a model of ATP regeneration. Supplying 150 mM ATP, GMAS enzyme could produce 16.8 ± 1.3 g/L L-theanine from 100 mM glutamate. When 5 mM ATP and 5 U/mL Ch PPK D82N-K103E were added, the yield of L-theanine was 16.6 ± 0.79 g/L with the conversion rate of 95.6 ± 4.5% at 4 h. Subsequently, this system was scaled up to 200 mM and 400 mM glutamate, resulting in the yields of L-theanine for 32.3 ± 1.6 g/L and 62.7 ± 1.1 g/L, with the conversion rate of 92.8 ± 4.6% and 90.1 ± 1.6%, respectively. In addition, we also constructed an efficient ATP regeneration system from glutamate to glutamine, and 13.8 ± 0.2 g/L glutamine was obtained with the conversion rate of 94.4 ± 1.4% in 4 h after adding 6 U/ mL GS enzyme and 5 U/ mL Ch PPK D82N-K103E , which further laid the foundation from glutamine to L-theanine catalyzed by GGT enzyme. This proved that giving the reaction an efficient ATP supply driven by the mutant enzyme enhanced the conversion rate of substrate to product and maximized the substrate value. This is a positively combination of high yield, high conversion rate and high economic value of enzyme catalysis. The mutant enzyme will further power the ATP-consuming biocatalytic reaction platform sustainably.
研究领域:
生物化学
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酶工程
·
代谢工程
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DOI
PubMed
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Yuqing Zhong,Yongling Lu,Lishuang Lv
Reactive carbonyl species (RCS) are generated during thermal food processing, and their accumulation in the body increases the risk of various chronic diseases. Herein, the RCS-scavenging ability of theanine, a unique nonproteinogenic amino acid, was evaluated in terms of the scavenging rate, reaction kinetics, and reaction pathway using LC–MS/MS. Three major products of theanine conjugated with acrolein (ACR) and glyoxal (GO) were prepared and identified using nuclear magnetic resonance. Thereafter, the simultaneous reactions of four types of RCS (namely, ACR, crotonaldehyde, methylglyoxal, and GO) with theanine were discussed in RCS–theanine and RCS–tea models. Under different reaction ratios, theanine could nonspecifically scavenge the four coexisting RCS by forming adducts with them. The amount of theanine–RCS adducts in green and black tea was more than that of catechin (epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin)–RCS adducts despite the lower content of theanine than catechins. Thus, theanine, as a food additive and dietary supplement, could demonstrate new bioactivity as a promising RCS scavenger in food processing.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Food Measurement and Characterization
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2025
·
IF 3.3
Pan Xiaoya,Wang Hongyue,Guo Keshuang,Zhang Tong,Li Xinnan,Zhang Xiangrong
The study aimed to prepare the chelate of L-theanine (LT) with zinc (Zn) and evaluate its stability, antioxidant and antidiabetic activity. The chelation mechanism between Zn 2+ and LT was investigated by ultraviolet-visible, Fourier transform infrared, scanning electron microscopy/energy dispersive spectrometer and 1 H nuclear magnetic resonance spectroscopy. L-theanine-Zn chelate (LT-Zn) was obtained using LT to Zn citrate in a mass ratio of 3:1 at pH 6 and 70 °C for 180 min with the chelation efficiency of 61.86 ± 1.26%. The results revealed the amino nitrogen atoms and carboxyl oxygen atoms in LT chelated with Zn ions, and the mass of the chelate was confirmed by liquid chromatography with tandem mass spectrometry. Scanning electron microscopy with the element analyzed by energy dispersive spectroscopy showed that the morphology of LT-Zn consisted of irregular granular particles with rough surface. The LT-Zn exhibited higher solubility and improved stability under 100 °C, various pH condition and different concentrations of glucose and NaCl ( p < 0.05) than that of sulfate Zn and Zn gluconate. Compared to sulfate Zn and Zn gluconate, the LT-Zn showed better stability during simulated gastrointestinal digestion. The chelate also exhibited antioxidant activity, as well as an inhibitory effect on α-glucosidase and α-amylase. Overall, the study provided a novel approach to prepare Zn nutraceuticals with antioxidant and antidiabetic properties.
研究领域:
食品科学
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营养学
·
生物化学
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产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2025
·
IF 6.6
Zongwei Hao,Jiameng Wang,Zhaofeng Li,Zhichao Shen,Hui Xu,Zhongyun Zhao,Zongjun Wu,Huijun Sun,Yixuan Xu,Mingming Zheng,Yibin Zhou,Yiqun Du,Zhenyu Yu
With the increasing number of patients with type II diabetes associated with starchy foods, the inhibition of starch digestion has become one of the most important strategies for limiting postprandial glucose elevation. However, indirect inhibition of starch digestibility through the starch digestive enzymes pathway remains poorly studied. Based on this, we found that L-theanine (THE) had the potential to inhibit starch digestive enzyme activity and investigated the mechanism based on multi-spectral and computer simulations. The results showed that the half-inhibitory concentration (IC 50 ) values of THE on α-amylase and α-glucosidase were 1.22 mmol/L and 2.77 mmol/L, respectively, which exhibited a mixed type of inhibition. Fluorescence quenching results and analyses showed that the mechanism of inhibition of THE with digestive enzymes had both static quenching, mainly based on non-covalent interactions such as van der Waals forces and hydrogen bonding, with binding energies of −3.19 and −7.76 kcal/mol, respectively (Molecular docking results). The multi-spectral analysis showed that the binding of THE changed the secondary structure of starch digestive enzymes and the conformation of polypeptide chains, thus inhibiting the activity. The findings of this study are expected to guide the development of food products with hypoglycaemic function using THE.
研究领域:
食品科学
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生物化学
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计算生物学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Xiuheng Xue,Haiyong He,Cunjun Liu,Li Wang,Lu Wang,Yueji Wang,Luping Wang,Chen Yang,Juhua Wang,Ruyan Hou
Diacylglycerol (DAG) is commonly used as fat substitute in food manufacture due to its functional properties, but DAG has poor emulsification and oxidation stability, which limits its wide application in food industry. In this work, fluorescence quenching data and thermodynamic parameters were analyzed to investigate the interaction mechanism between l -theanine (L-Th) and β-lactoglobulin (β-LG). DAG emulsion was prepared by using β-lactoglobulin-theanine (β-LG-Th) as surface stabilizer, and its emulsification and oxidation stability were evaluated. The results showed that the hydrophobic interaction played an important role on the conjugate of β-LG and L-Th due to the negative values for ΔG, positive values for ΔH and ΔS at pH 4.0, pH 6.0 and pH 8.0. The DAG has been better embedded by using β-LG-Th as surface stabilizer, and the droplet size was about 0.2 µm to 1.5 µm when the pH was 6.0, the ratio of L-Th to β-LG was 1:1. β-LG-Th as surface stabilizer for DAG can increase the ζ-potential and emulsion index, make the emulsion droplet size distribution more uniform. The l -theanine was better to be used to improve the emulsification stability and antioxidant capacity of DAG by binding β-LG as surface stabilizer.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Qi Zhou,Yuzhou Wang,Qiwei Cheng,Shaobo Duan,Yaqiong Li,Xiguo Cai,Lianzhong Zhang
The ultrasound microbubbles modified with the nanomaterial GO not only allow real-time monitoring of liver blood flow for disease diagnosis but also serve as drug delivery carriers, offering the dual benefits of diagnostic imaging and targeted therapy. This presents a highly promising strategy for the integrated diagnosis and treatment of hepatocellular carcinoma (HCC) patients. In this study, L-theanine (TH), a natural polyphenol with antioxidant, and antitumor, was used as a “green” reducing agent for graphene oxide (GO) to prepare nanoscale reduced graphene oxide (rGO-TH), which was then blended with SonoVue microbubbles to prepare composite microbubbles (SV@rGO-TH MBs) for the integrated diagnosis and treatment of HCC. The SV@rGO-TH MBs remain stable at higher Mechanical Index (MI), thereby enhancing contrast-enhanced ultrasound(CEUS) imaging effects and improving the accuracy of disease diagnosis. SV@rGO-TH MBs show significant antitumor activity, inhibiting HepG2 cancer cell growth in vivo and in vitro. Furthermore, combined with ultrasound irradiation, nanoscale rGO-TH more easily penetrates the vascular walls and accumulates in tumor tissues, enhancing the antitumor effect. Our research demonstrates that SV@rGO-TH MBs are a safe and effective ultrasound contrast agent (UCA) for the integrated diagnosis and treatment of HCC, providing insights for the early diagnosis and precise treatment of tumors.
研究领域:
医学影像学
·
肿瘤学
·
纳米医学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Lei Cai,Xiyu Mou,Jieshee Hong,Chun Cui
With the improvement of people's living standards and health awareness, reducing salt, sugar, and fat is gradually becoming the mainstream trend. In this work, we delved into the development of an innovative taste enhancer, N-lauroyl theanine (NLT), and its taste presentation mechanism. NLT was synthesized in the aqueous phase by enzyme-catalyzed and direct-heating methods using food-grade enzymes in yields of up to 64.33 % and 49.11 %, respectively. Sensory evaluation and molecular docking techniques revealed the potential of NLT to enhance salty, umami, sweet, and kokumi taste sensations and its taste presentation mechanism. Results revealed significant taste enhancement of saltiness, umami, sweetness, and kokumi and prolonged their duration in the oral cavity by 0.25–1 mg/L NLT. Molecular docking analyses showed that NLT had a strong binding affinity for a variety of taste receptors. These findings highlight the potential of NLT as a potent taste enhancer for the development of healthier salt/sugar-reduced foods.
研究领域:
食品科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE
·
2025
·Vol. 90
·期 2
·e70042
·
IF 3.4
Yue Qiu,Xiaolin Liu,Zhiye Huang,Fei Lyu,Xinyu Hu,Shenghua Han,Hao Ren,Anqiang Zhang
Anji Baicha ( Camellia sinensis ), one of the top 10 teas in China, possesses old leaves rich in bioactive ingredients yet is frequently discarded due to inferior taste. This study evaluated the effects of fermentation with Eurotium cristatum , a probiotic known to enhance bioactivity, on the primary nutrients and on the hypoglycemic and sedative properties of old leaves of Anji Baicha. Results indicated a considerable reduction in free amino acids and tea polyphenols post-fermentation. Conversely, the concentrations of flavonoids and theabrownins increased significantly, showing a positive correlation with the in vitro hypoglycemic effect. The contents of L-theanine and γ-aminobutyric acid (γ-GABA), known for their sedative effects, increased after fermentation, while caffeine and glutamate, renowned for their neural stimulation effect, decreased. Molecular docking revealed that L-theanine and γ-GABA may act as a sedative and sleep aid by competing for receptors with caffeine and glutamate, specifically NMDAR2A. This study not only introduces a novel approach for utilizing old leaves of Anji Baicha but also establishes a foundation for further investigating the hypoglycemic, sedative, and sleep-aiding effects of tea fermented with Eurotium cristatum . Practical Application This research offers a sustainable solution for repurposing the underutilized old leaves of Anji Baicha, enhancing their market value and contributing to the circular economy within the tea industry. The fermented tea could be integrated into health-conscious food and beverage products, targeting consumers seeking natural hypoglycemic and sleep-aiding alternatives. Additionally, the findings open avenues for the development of functional teas that cater to specific health needs, such as diabetes management and sleep improvement.
研究领域:
食品科学
·
生物化学
·
植物学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）