ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Yaxuan Qian,Zhuoran Jiang,Yan Long,Houguo Fei,Heng Song,Cunlan Guo
Electrochemistry enables numerous redox enzymatic reactions with high efficiency. Nitroaromatic molecules with diverse biological properties have been extensively applied in medicine. New strategies are continuously required for the nitration of aromatic molecules with improved yields and selectivity. Here, we report a reaction by combining electrochemistry and the enzyme ferredoxin-TxtE to drive the nitration of l-tryptophan (l-Trp). With methyl viologen as the electron mediator, such an electroenzymatic approach avoids the use of expensive β-nicotinamide adenine dinucleotide phosphate (NADPH) and results in a higher yield than the wild-type ferredoxin-NADP+ reductase-TxtE reaction. This electrochemically driven reaction also produces two nitro-l-Trp isomers, i.e., 4-nitro-l-Trp and 5-nitro-l-Trp, which can be regulated by an electric field and electron mediators. Moreover, when more polarized mediators are used, the selectivity is recovered to 4-nitro-l-Trp. The mechanistic study suggests that the selectivity of the electron mediators is attributed to the steric hindrance and polarity of bipyridiniums. This work affords a new catalytic strategy for the regulation and control of electroenzymatic catalysis, which is expected to extend the application of electroenzymatic reactions in synthesis, energy, and sensing fields.
研究领域:
电化学
·
酶学
·
有机化学
·
催化
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产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Ziwei Wang,Rui An,Yuxuan Dai,Hongxia Luo
In this work, carbon dots (CDs) were produced by one-step ultrasound technology with glucose as the precursor. The effective synthesis of CDs was characterized by Raman spectroscopy and UV-visible spectra. The as-prepared CDs were fixed on a glassy carbon electrode (GCE) via electrochemical deposition to fabricate CDs/GCE, which simultaneously detected dopamine (DA), uric acid (UA), L-tryptophan (Trp) and theophylline (TP). With the differential pulse voltammetry technique, the oxidation peak currents of these four biomolecules were significantly enhanced on CDs/GCE compared to those on bare GCE. The potential differences of DA-UA, UA-Trp, and Trp-TP were computed as 145 mV, 381 mV, and 323 mV, respectively. The broad linear ranges were 0.5-50 μM for DA, 3-75 μM for UA, 1-65 μM for Trp and 10-200 μM for TP with limits of detection (LODs) of 0.007 μM, 0.011 μM, 0.11 μM and 0.33 μM (S/N = 3), respectively. The CD/GCE sensor had good stability and strong anti-interference ability and was applicable to detecting actual samples.
研究领域:
分析化学
·
生物医学工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Wenjun Zhu,Yuwen Fan,Qiang Xu,Xinxin Liu,Bin Heng,Wenge Yang,Yonghong Hu
In this research, solubility of l-tryptophan in water, methanol, ethanol, acetone, isopropanol, n-butanol, acetonitrile, ethyl acetate, organic pure solvent, and in three binary mixed solvents (water + acetonitrile), (water + methanol), and (water + isopropanol) at the temperature range of T = 278.15–333.15 K was determined with the gravimetric method. The experimental results show that the solubility of l-tryptophan in the above solvents increased as temperature rose, and it achieved the highest dissolution efficiency in water. The improved Apelblat model, the Buchowski–Ksiazaczak λh model, the Redlich–Kister (CNIBS/R–K) model, and the Jouyban–Acree model were used to nonlinearly fit the experimental data of solubility, and the consistency was good. The physicochemical information of l-tryptophan provided in this report may be helpful for its extraction/separation, recrystallization, purification, and formulation development.
研究领域:
化学工程
·
药物化学
·
生物化学
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产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2015
·
IF 4.891
Jingxiang Yang,Yongli Wang,Hongxun Hao,Chuang Xie,Ying Bao,Qiuxiang Yin,Junbo Gong,Chen Jiang,Baohong Hou,Zhao Wang
L-Tryptophan was successfully crystallized in the form of spherulites by introducing trace amounts of gelatin into the crystallization solution. The physicochemical properties of L-tryptophan products were significantly improved by using this polymer-induced spherulitic growth strategy. This newly developed polymer-induced spherulitic growth strategy provides another choice for controlling the size distribution of particles. Furthermore, the formation and growth of these spherulites under different conditions was monitored in situ by using particle vision measurement and microscopy. It was found that the morphologies of spherulites could be influenced by the additives, the crystallization temperature, and the initial concentration of L-tryptophan. The influence of temperature on the growth rate of spherulites was investigated. It was found that the growth rate is constant at given temperatures. A population-based empirical model was developed and used to explain the spherulitic growth of L-tryptophan spherulites. It was verified that the growth of L-tryptophan spherulites is interface kinetics controlled.
研究领域:
化学工程
·
材料科学
·
药物结晶
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产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Bowen Zhang,Wei Liu,Xiangrong Wu,Jinhua Zhu,Weiping Hu,Abdelhadi El Jaouhari,Xiuhua Liu
In the past decade, carbon dots (CDs) have attracted considerable attention due to their excellent properties such as low toxicity, good biocompatibility, good fluorescence imaging, etc. Here, glutathione and l-tryptophan were used as carbon sources to hydrothermally synthesize CDs for sensitive and selective off/on detection of Fe3+ ions. The CDs are spherical nanoparticles with an average particle size of 3.8 nm and the presence of organic groups such as hydroxyl, carboxyl, sulfhydryl, and amino groups on their surface. The experiment results display that Fe3+ ions can be selectively and sensitively detected by quenching the fluorescence of CDs. Moreover, the fluorescence of the CDs+Fe3+ system can be restored after adding ascorbic acid. Thus, an off/on fluorescent probe for the determination of Fe3+ can be formed using the as-synthesized CDs solution. The CDs show a good linear range of 0–13.89 mM and a 0.0331 μM limit of detection for Fe3+, and the most probable mechanism concluded from ultraviolet–visible spectroscopy, electrospray ionization–mass spectrometry, and fluorescence spectrophotometry is a mixed static and dynamic quenching. Furthermore, the cytotoxicity experiment results show that CDs have low toxicity and can be used for intracellular imaging.
研究领域:
分析化学
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生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Li Zhang,Chao Li,Yue Chen,Shaobin Li,Xue Wang,Fengbo Li
L-tryptophan (L-Trp) is crucial for human metabolism, and its imbalance or deficiency can lead to certain diseases, such as insomnia, depression, and heart disease. Since the body cannot synthesize L-Trp and must obtain it from external sources, accurately monitoring L-Trp levels in food is essential. Herein, a nanocomposite film based on polyoxometalate (P 2 Mo 17 V), Ti 3 C 2 T x MXene , and chitosan (Cs) was developed through a green electrostatically mediated layer-by-layer self-assembly strategy for electrochemical detection of L-Trp. The composite film exhibits fast electron transfer and remarkable electrocatalytic performance for L-Trp with a wide linear range (0.1–103 μM), low limit of detection (0.08 μM, S/N = 3), good selectivity, reproducibility, and repeatability. In milk sample, the recoveries of L-Trp were from 95.78% and 104.31%. The P 2 Mo 17 V/Cs-Ti 3 C 2 T x electrochemical sensor not only provides exceptional recognition and detection capabilities for L-Trp but also shows significant potential for practical applications, particularly in food safety and quality control .
研究领域:
食品科学
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分析化学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2017
·Vol. 24
·期 1
·16-24
·
IF 0
Sun Jinsheng,Wei Dongmei,Lv Hao
This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent l -Tryptophan ( l -Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV–Vis spectrophotometer and X-ray diffraction (XRD) for size and morphological information. The effects of the specific additives of PVP ((C 6 H 9 NO)
n
), CTAB (C 16 H 33 (CH 3 ) 3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.
研究领域:
材料科学
·
纳米生物学
·
环境科学
✓ 已验证
产品关联
DOI
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
·
IF 2.536
Yusheng Yuan,Liu Yang,Shaopu Liu,Jidong Yang,Hui Zhang,Jingjing Yan,Xiaoli Hu
A sensitive fluorescence sensor for warfarin was proposed via quenching the fluorescence of l -tryptophan due to the interaction between warfarin and l -tryptophan. Warfarin, as one of the most effective anticoagulants , was designed and synthesized via lipase from porcine pancreas (PPL) as a biocatalyst to catalyze the Michael addition of 4-hydroxycoumarin to α, β-unsaturated enones in organic medium in the presence of water. Furthermore, the spectrofluorometry was used to detect the concentration of warfarin with a linear range and detection limit (3σ/k) of 0.04–12.0 μmol L − 1 (R 2 = 0.994) and 0.01 μmol L − 1 , respectively. Herein, this was the first application of bio-catalytic synthesis and fluorescence for the determination of warfarin. The proposed method was applied to determine warfarin of the drug in tablets with satisfactory results.
研究领域:
药物化学
·
分析化学
·
生物催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Rongli Zhang,Ye Zhu,Jing Huang,Sheng Xu,Jing Luo,Xiaoya Liu
The electrophoretic deposition (EPD) of self-assembled nanoparticles (NPs) on the surface of an electrode is a new strategy for preparing sensor coating. By simply changing the deposition conditions, the electrochemical response for an analyte of deposited NPs-based coating can be controlled. This advantage can decrease the difference between different batches of sensor coating and ensure the reproducibility of each sensor. This work investigated the effects of deposition conditions (including deposition voltage, pH value of suspension, and deposition time) on the structure and the electrochemical response for l-tryptophan of sensor coating formed from Au-doped poly(sodium γ-glutamate) with pendant dopamine units nanohybrids (Au/γ-PGA–DA NBs) via the EPD method. The structure and thickness of the deposited sensor coating were measured by atomic force microscopy, which demonstrated that the structure and thickness of coating can be affected by the deposition voltage, the pH value of the suspension, and the deposition time. The responsive current for l-tryptophan of the deposited sensor coating were measured by differential pulse voltammetry, which showed that the responsive current value was affected by the structure and thickness of the deposited coating. These arguments suggested that a rich design-space for tuning the electrochemical response for analyte and a source of variability in the structure of sensor coating can be provided by the deposition conditions. When Au/γ-PGA–DA NBs were deposited on the electrode surface and formed a continuous coating with particle morphology and thinner thickness, the deposited sensor coating exhibited optimal electrochemical response for l-tryptophan.
研究领域:
分析化学
·
材料科学
·
生物传感
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
BingBing Wang,Jian-Zhong Xu,Shuai Liu,Zhi-Ming Rao,Wei-Guo Zhang
L-Tryptophan hydroxylation catalyzed by tryptophan hydroxylase (TPH) presents a promising method for synthesizing 5-hydroxytryptophan (5-HTP), yet the limited activity of wild-type human TPH2 restricts its application. A high-activity mutant, MT10 (H318E/H323E), was developed through semi-rational active site saturation testing (CAST) of wild-type TPH2, exhibiting a 2.85-fold increase in k cat / K m over the wild type, thus enhancing catalytic efficiency . Two biotransformation systems were developed, including an in vitro one-pot system and a Whole-Cell Catalysis System (WCCS). In the WCCS, MT10 achieved a conversion rate of only 31.5 % within 32 h. In the one-pot reaction, MT10 converted 50 mM L-tryptophan to 44.5 mM 5-HTP within 8 h, achieving an 89 % conversion rate, outperforming the M1 (NΔ143/CΔ26) variant. Molecular dynamics simulations indicated enhanced interactions of MT10 with the substrate, suggesting improved binding affinity and system stability. This study offers an effective approach for the efficient production of 5-HTP.
研究领域:
生物化学
·
分子生物学
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Wenjing Wang,Yumin He,Suxiang He,Xiaoying Liu,Qing-wen Gui,Lei Deng,Hui Wang,Zhong Cao,Zemeng Feng,Benhai Xiong,Yulong Yin
L - Tryptophan (L-Trp), one of the essential amino acids, is crucial for human physiological homeostasis and a limiting amino acid in animal feed. In addition, L-Trp is a precursor of some important biomolecules in the body, such as pentraxin and melatonin. Disorders of L-Trp metabolism in the body may cause Alzheimer's or Parkinson's disease. Therefore, monitoring L-Trp levels in the body fluids quickly and accurately is essential. A colorimetric biosensor was developed for the rapid detection of L-Trp in solutions by coupling a novel, screened, and validated peptide aptamer with Au nanoparticles via the Au-S bond. The biosensor showed a wide linear detection range of 1 µM − 1000 µM, and in addition, it was simple to construct, and the reaction time was as short as 10 s. In the analysis of L-Trp in actual porcine serum samples, the relative standard deviations were 4.52 % to 3.01 % compared with those of the high-performance liquid chromatography method, and the spiked recoveries were 99.2 % to 100.2 %. This new type of recognition probe is likely to gain attention in the field of bioanalysis owing to its biocompatibility, ease of modification, and easy linkage to nanomaterials.
研究领域:
生物化学
·
分析化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
BIOELECTROCHEMISTRY
·
2011
·
IF 3.52
Xiao Liu,Liqiang Luo,Yaping Ding,Daixin Ye
A novel poly-glutamic acid (PGA) film modified carbon paste electrode (CPE) incorporating carbon nanotubes (CNTs) was first prepared for the determination of l -tryptophan ( l -Trp). Scanning electron microscopy and Fourier transform infrared spectroscopy were applied for characterization of the surface morphology of the modified electrodes and cyclic voltammetry was used to investigate the electrochemical properties of the proposed electrode towards the oxidation of l -Trp. Optimization of the experimental parameters was performed with regard to pH, ratio of CNTs, concentration of glutamic acid , electro-polymerization cycles, accumulation time and concentration of sodium dodecylbenzene sulfonate . The linearity between the oxidation peak current and the l -Trp concentration was obtained in the range of 5.0 × 10 − 8 to 1.0 × 10 − 4 M with a detection limit of 1.0 × 10 − 8 M ( S / N = 3) and the sensitivity was calculated to be 1143.79 μA∙mM − 1 ∙ cm − 2 . In addition, the PGA modified CPE incorporating CNTs displayed high selectivity, good stability and reproducibility, making it suitable for the routine analysis of l -Trp in clinical use.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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