FOOD CHEMISTRY
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2024
·
IF 8.5
Lei Cai,Liyu Li,Xu Zhao,Lu Wang,Yuqin Cheng,Wenxiang Gao,Chun Cui
N-lauroyl-L-tryptophan (LT), which has the strongest potential flavor-presenting activity, was skillfully screened from numerous N-Lau-AAs docked to different taste receptors by molecular simulation techniques. Subsequently, LT was synthesized employing food-grade commercial enzymes and structurally characterized, the optimized yields of LT could reach 69.08%, 76.16%, and 50.40%, respectively. Sensory and E -tongue evaluations showed that LT at 1 mg/L significantly benefited the performance of different taste sensations and exhibited different bitter taste masking effects: L-Ile (68.42%), L-Trp (68.18%), D-salicylic acid (48.48%) and quinine (35.00%). The molecular docking results illustrated that LT had a high affinity for various taste receptors , dominated by hydrogen bonding and hydrophobic interactions. This work provided a rare systematic elucidation of the potential and mechanism of enzymatically synthesized LT in enhancing taste properties. It provides novel insights into the directions and strategies for the excavation and innovation of flavor enhancers and food flavors.
研究领域:
食品科学
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分子生物学
·
生物化学
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PubMed
高影响因子
Journal of Pharmaceutical Analysis
·
2019
·
IF 4.44
Dongsheng Xu,Elena Sánchez-López,Qiqin Wang,Zhengjin Jiang,María Luisa Marina
An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl (FMOC) derivatized amino acids by nano-liquid chromatography. The mobile phase was optimized including the apparent pH, content of ACN, and concentration of the buffer to obtain a satisfactory enantioresolution performance. 27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested, and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them. Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity, precision, accuracy, limits of detection (LOD) and quantitation (LOQ) showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements. LOD and LOQ values were 9.3 and 31 μM for norvaline enantiomers and 7.5 and 25 μM for tryptophan enantiomers, respectively. The contents of d -norvaline and d -tryptophan were below their respective LODs in all the analyzed samples. Quantitation of l -tryptophan and l -norvaline showed good agreement with the labeled contents except for one sample which did not show presence of l -norvaline, contrary to the label indication.
研究领域:
分析化学
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生物化学
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PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2026
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IF 6.7
Cheng Chen,Yamin Huang,Juan Li,Meijuan Xu,Hui Li,Guoqiang Xu,Jinsong Shi,Zhenghong Xu,Xiaomei Zhang
l-Tryptophan, an essential amino acid, serves as a critical precursor for the biosynthesis of numerous bioactive compounds. In this study, we engineered tryptophan synthase (TrpS) to develop an efficient cell factory for l-tryptophan production. Initially, EcTrpS from Escherichia coli K-12 was expressed in E. coli BL21 (DE3) to construct strain BS, which produced 836.43 mg/L of l-tryptophan. To alleviate substrate inhibition, we constructed a mutant library of 104–105 variants through two rounds of error-prone PCR and utilized a biosensor employing a green fluorescent protein to report l-serine consumption for screening TrpS mutants. Mutant C10 showed a 375% increase in enzyme activity compared with strain BS. Computational analysis was used to explore an improved catalytic mechanism. Finally, through systematic process optimization and catalytic strategy, strain C10 produced 94.2 g/L of l-tryptophan, the highest titer via whole-cell transformation. This study provides new perspectives and strategies for TrpS engineering and the industrial production of l-tryptophan.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Zhiyong Zhou,Lichao He,Yu Mao,Wenshuai Chai,Zhongqi Ren
Enantioseparation of racemic tryptophan is very important for pharmaceutical production. Conventional separation methods are high costly, energy intensive and environmentally unfriendly. Permeation separation based on membrane separation technique is a promising technology with advantages of energy efficient, clean and no additives. However, lots of organic compounds are commonly used for the traditional preparation of various membranes for enantioseparation of racemic tryptophan. Thus, we developed a totally green and clean preparation method using nature polymer sodium alginate as functional polymer, water as solvent and CaCl 2 as crosslinking agent. Besides, polyvinylidene fluoride membrane was selected as supported membrane. Molecularly imprinted technology with d -Tryptophan as template molecule was introduced to enlarge mass transfer flux. Various methods were used in characterization of molecularly imprinted composite membrane (MICM) and non-imprinted composite membrane (NICM). Effects of preparing conditions, permeation conditions and concentration polarization on permeation performance of MICM by pressure-driven were investigated. High enantiomeric excess ( ee % > 98%) of the permeation solution could be obtained under mild conditions. Reducing the presence of concentration polarization was beneficial to maintaining high ee % (>98%). Moreover, the thermo and chemical stability of MICM were studied too. Comparison with previous studies indicated that the proposed totally green and clean method was not only low costly and environment friendly but also beneficial to significantly increasing ee .
研究领域:
生物化学
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制药工程
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材料科学
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高影响因子
RSC Advances
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2016
·Vol. 6
·期 111
·109992-110000
·
IF 3.289
Zhiyong Zhou,Ke Cui,Yu Mao,Wenshuai Chai,Nian Wang,Zhongqi Ren
Enantioseparation of chiral compounds is important for pharmaceutical production. Chiral resolution of racemic tryptophan has attracted increasing attention. Traditional separation methods have the disadvantages of being high cost, energy intensive and environmentally unfriendly. Membrane permeation seems promising for application in the enantioseparation of racemic tryptophan with the advantages of energy efficiency and no additives. However, lots of organic compounds are commonly used for the preparation of various membranes for enantioseparation of racemic tryptophan. Therefore, we prepared a molecularly imprinted self-supported membrane (MISM) using a green and clean method with natural polymer sodium alginate (SA) as the functional polymer, water as the solvent and CaCl2 as the crosslinking agent. The crosslinking by CaCl2 was confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The surface and internal structures of the MISM and non-imprinted self-supported membrane (NISM) were observed by atomic force microscope (AFM) and scanning electron microscope (SEM). The addition of a template molecule can significantly improve the MISM surface roughness. The compact structures of MISM and NISM were confirmed by the cross-sectional images. The thermo stability of MISM was studied. In addition, the effects of pH and crosslinking time on the swelling behavior of MISM were investigated. A high concentration of OH− in alkali solution can remarkably weaken the electrostatic interaction between Ca2+ and COO−. The effects of preparation conditions, permeation conditions and concentration polarization on the pressure-driven permeation performance of MISM were investigated. Ultrahigh enantioseparation performance in 99% ee of the permeation solution can be obtained under mild conditions. Reducing the concentration polarization by increasing the environmental temperature and continuous stirring is beneficial to obtaining ultrahigh ee. Comparison with previous studies on pressure-driven permeation performance indicates that the proposed green and clean preparation method for a molecularly imprinted self-supported membrane is not only environmentally friendly but also efficient in obtaining ultrahigh ee.
研究领域:
生物化学
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环境科学
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制药工程
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DOI
高影响因子
Frontiers in Nutrition
·
2026
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IF 5.5
Wei Sun,Yu Wang,Xin Zhang,Yifan Yue,Xiaoxuan Sun,Jiyan Miao,Shihang Han,Zhiqiang Zhou,Xiuguo Wang,Wentao Zhu
IntroductionThe extensive production of environmental pollutants has heightened susceptibility to intestinal disorders, potentially through alterations in the gut microbiota. However, the precise role of the gut microbiota in environmental pollutant-induced inflammation remains incompletely understood.MethodsIn this study, wild-type and IL-10−/− mice were employed to simulate the responses of healthy individuals and those genetically predisposed to inflammatory bowel disease (IBD) to environmental toxicants. Mice were exposed to metalaxyl, and an integrated multi-omics approach combining microbiome and metabolome profiling with machine learning was conducted to investigate the underlying mechanisms. Additionally, dietary tryptophan supplementation was administered to evaluate its protective effects.ResultsMetalaxyl exposure induced low-grade colonic inflammation in wild-type mice and triggered severe colitis in IBD-susceptible mice. Multi-omics analysis revealed that metalaxyl significantly disrupted gut microbial composition, reduced the synthesis of endogenous tryptophan-derived metabolites, and inhibited aryl hydrocarbon receptor (AhR) signaling, ultimately initiating intestinal barrier dysfunction and inflammatory cascades. Notably, dietary tryptophan restored gut tryptophan metabolite levels, strengthened AhR signaling, mitigated intestinal inflammation, and repaired barrier defects.DiscussionThis study identifies the gut microbiota as a central mediator of environmental pollutant-induced IBD and demonstrates that a high-tryptophan diet exerts beneficial effects against environmental colitis via the AhR axis. Furthermore, the stable phenotypes and high reproducibility of this dual-genotype mouse model underscore its utility as an ideal platform for investigating the enterotoxic effects of environmental pollutants.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Jingpu Zhang,Lei Pan,Yan Wang,Lin Yin,Li Xu,Jie Tao,Lijun Zhang,Zhaoqin Zhu,Daxiang Cui,Feng Li,Tie Fu Liu
Tryptophan (Trp) as an essential amino acid plays critical roles in regulating multiple cell activities, and the changes of its circulating level usually indicate disease status such as the severity of acute inflammation sepsis. However, the current technology for Trp detection mostly relies on chromatography that cannot meet the rapid and simple detection requirement in monitoring sepsis. Herein, a label-free fluorescent nanosensor was constructed to detect Trp and its carrier protein - human serum albumin (HSA) in plasma. The nanosensor consists of a cytosine (C) - rich signal probe of DNA-templated silver nanoclusters (AgNCs/DNA) and a Trp (Trp) aptamer - based capture probe with a guanine (G) - rich overhang. Trp was found to trigger G-rich sequence-mediated fluorescence enhancement effect for AgNCs/DNA under UV irradiation which offers energy to induce the redox process between limited Trp and silver ions bound on the DNA probes . Based on this photochemical property, the nanosensor exhibited a linear response in the range of 0.05–60 μM with the limit of detection of 0.43 μM for Trp, superior to the current fluorescence-based detection method, and it gave specific response to indole group. When applied in plasma detection, the nanosensor resisted physiological level of NaCl in plasma, but was quenched by trace volume of HSA, which facilitates the combined HSA detection using only 1 μL plasma sample. The simple procedure of “mix, exposure and detection” together with its ultralow sampling volume, time-saving, cost-effective, sensitive and selective properties endow the nanosensor great potentials for future Trp detection-based clinical use.
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高影响因子
Biotechnology Journal
·
2024
·Vol. 19
·期 4
·2300557
·
IF 3.2
Han-Yu Liu,Feng Qian,Hai-Min Zhang,Qian Gui,Yao-Wu Wang,Pu Wang
The halogenase-based catalysis is one of the most environmentally friendly methods for the synthesis of halogenated products, among which flavin-dependent halogenases (FDHs) have attracted great interest as one of the most promising biocatalysts due to the remarkable site-selectivity and wide substrate range. However, the complexity of constructing the NAD + -NADH-FAD-FADH 2 bicoenzyme cycle system has affected the engineering applications of FDHs. In this work, a coenzyme self-sufficient tri-enzyme fusion was constructed and successfully applied to the continuous halogenation of L -tryptophan. Sp FDH was firstly identified derived from Streptomyces pratensis , a highly selective halogenase capable of generating 6-chloro-tryptophan from tryptophan. Then, using gene fusion technology, Sp FDH was fused with glucose dehydrogenase (GDH) and flavin reductase (FR) to form a tri-enzyme fusion, which increased the yield by 1.46-fold and making the coenzymes self-sufficient. For more efficient halogenation of L -tryptophan, a continuous halogenation bioprocess of L -tryptophan was developed by immobilizing the tri-enzyme fusion and attaching it to a continuous catalytic device, which resulted in a reaction yield of 97.6% after 12 h reaction. An FDH from S. pratensis was successfully applied in the halogenation and our study provides a concise strategy for the preparation of halogenated tryptophan mediated by multienzyme cascade catalysis.
研究领域:
生物技术
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生物化学
·
酶学
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PubMed
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2015
·
IF 2.219
Fang Wang,Wencheng Gong,Lili Wang,Zilin Chen
Selective recognition of d -tryptophan ( d -Trp) in the presence of Cu(II) was investigated at poly- l -lysine (p-l-Lys) film using electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). p-l-Lys film was immobilized on a glassy carbon electrode (GCE) by cyclic voltammetry between 0.0 and 1.9 V in 20 mM phosphate buffer solution (pH 8.6). After the p-l-Lys/GCE electrode was incubated with d -Trp solution containing Cu(II) ions, obvious enhancement of electron transfer resistance and decrease of voltammetric current could be observed. If d -Trp was replaced by l -tryptophan (l-Trp), there was no apparent resistance and current changes. Moreover, no resistance and current changes could be found in the absence of Cu(II). It may be due to the formation of Cu complex with l -lysine and d -tryptophan. Finally, this method was successfully applied to monitoring enantiomeric composition of the d -Trp and l-Trp mixtures.
研究领域:
生物化学
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分析化学
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PubMed
高影响因子
Marine Drugs
·
2022
·Vol. 20
·期 2
·85
·
IF 6.085
Yinglu Wang,Qian Zheng,Li Li,Lile Pan,Hu Zhu
Quorum sensing (QS) can regulate the pathogenicity of bacteria and the production of some virulence factors. It is a promising target for screening to find anti-virulence agents in the coming post-antibiotics era. Cyclo (L-Trp-L-Ser), one variety of cyclic dipeptides (CDPs), isolated from a marine bacteriumRheinheimera aquimaris, exhibited anti-QS activity againstChromobacterium violaceumCV026 andPseudomonas aeruginosaPAO1. Unlike the CDPs composed of phenylalanine or tyrosine, the anti-QS activity has been widely studied; however, cyclo (L-Trp-L-Ser) and derivatives, containing one tryptophan unit and one non-aromatic amino acid, have not been systematically explored. Herein, the cyclo (L-Trp-L-Ser) and seven derivatives were synthesized and evaluated. All tryptophane-contained CDPs were able to decrease the production of violacein inC.violaceumCV026 and predicted as binding within the same pocket of receptor protein CviR, but in lower binding energy compared with the natural ligand C6HSL. As forP. aeruginosaPAO1, owning more complicated QS systems, these CDPs also exhibited inhibitory effects on pyocyanin production, swimming motility, biofilm formation, and adhesion. These investigations suggested a promising way to keep the tryptophan untouched and make modifications on the non-aromatic unit to increase the anti-QS activity and decrease the cytotoxicity, thus developing a novel CDP-based anti-virulence agent.Keywords:anti-quorum sensing;cyclic dipeptides;tryptophane;Pseudomonas aeruginosa;biofilm;bacterial adhesion
研究领域:
微生物学
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药理学
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分子生物学
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Yunchang Fan,Xing Dong,Yun Li,Yingying Zhong,Juan Miao,Shaofeng Hua,Yongchun Sun
In this work, several hydroxyl-functionalized ionic liquids (ILs) were synthesized and used to extract tryptophan from the aqueous phase. The experimental results indicated that the hydroxyl-functionalized ILs presented better extraction ability than the dialkylimidazolium-based ILs. The extraction efficiency was significantly influenced by the pH of the aqueous phase. Moreover, the cationic form of tryptophan preferred to transfer into the IL phase, thereby suggesting a cation-exchange extraction mechanism. Driving forces of the extraction processes included hydrogen bonding, hydrophobicity, π–π stacking, and the screening effect. Among these factors, hydrogen bonding was the main parameter, as suggested by the results of thermodynamic analysis. After extraction, [C1C6OHim]NTf2 could be reused by using the pH swing effect. These findings demonstrate that [C1C6OHim]NTf2 is a good alternative to conventional solvents for recovering tryptophan from the aqueous phase.
研究领域:
生物化学
·
分离科学
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DOI
高影响因子
ANALYTICAL LETTERS
·
2023
·
IF 2
Zhenmin Zhai,Zhefeng Fan
Tryptophan is an essential amino acid that is an important part of the human diet. In this work, label-free photoluminescence sensing based upon persistent luminescent nanoparticles (PLNPs) Zn0.8Ga2O4: Cr3+ is reported to determine tryptophan. Following 254 nm excitation, the PLNPs released luminescence after storing the absorbed light. Compared to the standard fluorescence, the persistent afterglow of the PLNPs was used for detection and imaging without external illumination, thereby eliminating autofluorescence and scattered light generated by biological substrates. For tryptophan concentrations from 4 to 240 µM, a linear relationship was described by F/F0 = 0.9416 − 0.0024 [Trp] with a correlation coefficient of 0.9911 and a detection limit of 0.19 µM. The recoveries of analyzed samples were between 97.9 and 101.9% providing good accuracy and simple methodology.
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高影响因子
危险品化学品经营许可证（带存储）