Analytical Methods
·
2021
·Vol. 13
·期 17
·2011-2020
·
IF 2.896
Yi-Xin Sun,Dan-Dan Zhang,Yang Sheng,Defeng Xu,Rong Zhang,Mark Bradley
The β-CD@PEI-Fc chiral interface was prepared based on the supramolecular host–guest interaction between ferrocene (Fc) grafted polyethyleneimine (PEI-Fc) and chiral β-cyclodextrin (β-CD). SEM results show that β-CD@PEI-Fc interface has a regular spatial structure, which can effectively distinguish tryptophan (Trp) enantiomers. Under the optimal conditions, differential pulse voltammetry shows that the peak current ratio (ID/IL) of Trp enantiomers can reach 2.84 at 15 °C. More interestingly, the β-CD@PEI-Fc/GCE exhibited chiral recognition of D-Trp and L-Trp via water contact angle measurements. There was a good linear relationship between the peak current and the concentration of Trp enantiomers in the range from 0.005 mM to 0.10 mM. Finally, the chiral interface can be applied for quick detection of the proportion of isomers in Trp racemic solution, which is very important for chiral recognition in racemic mixture of chiral compounds. Meanwhile, the β-CD@PEI-Fc/GCE showed good stability and reproducibility.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Qianwen Lian,Ai Luo,Zhenzhen An,Zhuang Li,Yongyang Guo,Dongxia Zhang,Zhonghua Xue,Xibin Zhou,Xiaoquan Lu
A novel and uniform gold nanoparticles/tryptophan-functionalized graphene nanocomposite (AuNPs/Trp-GR) has been successfully fabricated by directly electrochemical depositing gold onto the surface of tryptophan-functionalized graphene (Trp-GR). The nanostructure of AuNPs/Trp-GR was characterized by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). It was demonstrated that Au nanoparticles were well dispersed on the surface of Trp-GR which might attribute to the more binding sites provided by Trp-GR for the formation of Au nanoparticles. The electrocatalytic activity of the AuNPs/Trp-GR towards the dopamine (DA) was systematically investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimum conditions, a wide and valuable linear range (0.5–411 μM), a low detection limit (0.056 μM, S/N = 3), good repeatability and stability were obtained for the determination of DA. Furthermore, the modified electrode was successfully applied to real samples analysis.
研究领域:
材料科学
·
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 45
·
IF 1.768
Xiaoyu Sun,Junping Zhang,Chengxian Yin,Juantao Zhang,Jiao Han
Scale deposition, which severely damages oil exploration, is a difficulty encountered in oil fields. Scale inhibitors are widely used for controlling scales. Poly(aspartic acid) (PASP) is attracting more and more attention with increasing environmental concern and discharge limitations. However, PASP's poor inhibition in a high-temperature environment markedly limits its wide use. Thus, poly(aspartic acid)–tryptophan grafted copolymer (PASPTR) was synthesized to improve the inhibition efficiency of PASP. The results show that the reactant of PASPTR has a great effect on its inhibition performance. PASPTR was found to inhibit the precipitation of CaSO 4 close to 90% at concentrations as low as 0.4 mg/L at 50°C. The inhibition efficiency of PASPTR against CaCO 3 was close to 100% with the concentration of 2 mg/L at 50°C. Scanning electron microscopy and X-ray diffraction analyses, which showed the morphological and crystal structural changes of CaCO 3 and CaSO 4 precipitation, verified the excellent inhibition performance of PASPTR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42739.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 4
·2960-2974
·
IF 2.993
Zhu Han-Yan,Song Xiao-Dong,Yang Xiao-Rong,Cheng Chang-Jing,Yu Hai-Rong,Zhang Huai-Hao
Herein, we report a simple and facile strategy to prepare one kind of smart chiral magnetic nanoparticles (Fe 3 O 4 @PDA@PNG-CD) with high enantioselectivity via combining mussel-inspired polydopamine (PDA) chemistry with surface-initiated atom transfer radical polymerization for effective enantioseparation of tryptophan enantiomers ( dl -Trp). The PDA thin layer plays a pivotal role in fabricating high-density poly( N -isopropylacrylamide- co -glycidyl methacrylate)- β -cyclodextrin (PNG-CD) smart polymer brushes onto the Fe 3 O 4 NPs. The grafted PNG-CD plays a significant role in greatly boosting the enantioselectivity of the Fe 3 O 4 @PDA@PNG-CD, which is composed of the poly( N -isopropylacrylamide- co -glycidyl methacrylate) (PNG) copolymer chains with numerous appended β -cyclodextrin ( β -CD) units. The β -CD units serve as chiral selectors capable of selectively recognizing and binding l -tryptophan ( l -Trp) into their cavities by forming stable host–guest inclusion complexes of β -CD/ l -Trp, and the PNIPAM chains act as microenvironmental adjustors for the inclusion constants of β -CD/ l -Trp complexes. Operating temperature and initial concentrations of dl -Trp are two important factors that significantly affect the separation efficiency of dl -Trp and the enantioselectivity of the Fe 3 O 4 @PDA@PNG-CD. Furthermore, the Fe 3 O 4 @PDA@PNG-CD also demonstrates satisfactory recycling and excellent magnetic separability from enantiomeric solution. Such smart chiral magnetic NPs with high enantioselectivity developed in this study show great potentials in direct enantioseparation of various chiral compounds.
研究领域:
材料科学
·
生物化学
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Lian-Di Guo,Ya-Ya Song,Hai-Rong Yu,Li-Ting Pan,Chang-Jing Cheng
Multifunctional microspheres simultaneously possessing chirality, magnetism and thermosensitivity show great potentials in direct enantiomeric separation. Herein we report a novel type of smart chiral magnetic microspheres with core/shell/shell structures (Fe 3 O 4 @SiO 2 @PNCD) and its application in enantioselective adsorption of tryptophan (Trp) enantiomers. The prepared Fe 3 O 4 @SiO 2 @PNCD are composed of a Fe 3 O 4 nanoparticle core, an acidic-resistant SiO 2 middle shell and a thermosensitive microgel functional shell (PNCD). The PNCD plays an important role in the enantioselective adsorption of Trp enantiomers. The β -cyclodextrin ( β -CD) molecules on the PNCD act as smart receptors or chiral selectors, and can selectively recognize and bind L -Trp enantiomers into their cavities by forming host-guest inclusion complexes. The poly( N -isopropylacrylamide) (PNIPAM) chains on the PNCD serve as microenvironmental adjustors for the association constants of β -CD/ L -Trp complexes. The fabricated Fe 3 O 4 @SiO 2 @PNCD demonstrate fascinating temperature-responsive chiral recognition and adsorption selectivity toward Trp enantiomers. Most importantly, the desorption of Trp enantiomers and the regeneration of the Fe 3 O 4 @SiO 2 @PNCD can be easily achieved via simply changing the operation temperature. Moreover, the regenerated Fe 3 O 4 @SiO 2 @PNCD can be readily recovered from the amino acids enantiomeric solution under an external magnetic field for reuse. The present study provides a novel strategy for the direct enantioselective adsorption and separation of various enantiomeric compounds.
研究领域:
生物化学
·
材料科学
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2023
·
IF 3.4
Feifei Song,Tao Gu,Lin Zhang,Jiaxing Zhang,Shengping You,Wei Qi,Rongxin Su
5-Hydroxytryptophan (5-HTP) is a chemical precursor of serotonin, which synthesizes melatonin and serotonin in animals and regulates mood, sleep , and behavior. Tryptophan hydroxylase (TPH) uses tetrahydrobiopterin (BH4) as a cofactor to hydroxylate L -tryptophan ( L -Trp) to 5-HTP, and the low catalytic activity of TPH limits the rate of hydroxylation of L -Trp. In this study, the catalytic mechanism and structural features of L -Trp-TPH1-BH4 were investigated, and the catalytic activity was improved using a rational design strategy. Then the S337A/F318Y beneficial mutation was obtained. Molecular dynamics simulations showed that the S337A/F318Y mutant formed a salt bridge with TPH1 while forming an additional hydrogen bond with the substrate indole ring, stabilizing the indole ring and enhancing the binding affinity of the variant to L -Trp. As a result, the yield of 5-HTP was increased by 2.06-fold, resulting in the production of 0.91 g/L of 5-HTP. The rational design of the TPH structure to improve the hydroxylation efficiency of L -Trp offers the prospect of green production of 5-HTP.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yadong Wang,Guosheng Niu,Xiaofei Cao,Zhichao Yang,Yuan Dong,Guitao Feng,Yingliang Liu,Jizheng Wang,Shaokui Cao
Organic-inorganic hybrid perovskites have already been employed as promising light-sensitive materials for high-performance photodetectors (PDs) due to their intriguing optoelectronic features. Nonetheless, such perovskite-based PDs often suffer from low sensitivity, high dark current and inevitable degradation. In this work, a novel multifunctional molecule l -tryptophan ethyl ester hydrochloride ( l -TEEH) was used to treat the surface defects of triple-cation mixed halide perovskite film. It is found that the modulator with multiple functional groups can effectively passivate the uncoordinated ions (Pb 2+ and I - ) and halide (I and Cl) vacancies of the perovskite film. Owing to the reduced defects, the dark current of the pristine perovskite PD significantly decreases from ∼ 10 -9 A to ∼ 10 -11 A after the l -TEEH treatment. Moreover, the perovskite PD with the l -TEEH treatment exhibits a large photoresponsivity (1.27 A/W) and an ultrahigh on/off ratio (∼9 × 10 3 ). More impressively, the optimized device shows excellent stability in air with a relative humidity of 40–50 %. Furthermore, the reliable imaging capability of perovskite device with the l -TEEH treatment is also successfully demonstrated.
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Xiaoxun Lu,Jiabin Hong,Jing Zhang,Qian Liu,Ganzhong Liao,Yanwei Shi,Huanwen Tang,Xiaoshan Liu
Triphenyl phosphate (TPhP) is an organophosphate flame retardant widely distributed in the environment. The neurodevelopmental toxicity of TPhP has been observed in animals and humans. Previously, we found that prenatal TPhP exposure disturbed placental tryptophan metabolism, impaired neurodevelopment in male offspring, and induced abnormal neurobehavior; however, the underlying mechanisms are unknown. In this study, using the trophoblast cell line JEG-3, we found that TPhP altered gene and protein expression in the tryptophan metabolism pathway, inhibited the tryptophan-serotonin pathway, and activated the tryptophan-kynurenine pathway. Meanwhile, TPhP induced oxidative stress by activating monoamine oxidase A (MAOA), promoting inflammatory factors including nuclear factor kappa-B (NFκB), interleukin-6, and tumor necrosis factor α. The NFκB inhibitor sulfasalazine could alleviate the effects of TPhP on tryptophan metabolism disturbance. The MAOA inhibitor clorgyline or the antioxidant N -acetylcysteine can mitigate oxidative stress and eliminate TPhP-induced inflammatory factors and tryptophan metabolism disturbances. The data above suggest that TPhP disturbed tryptophan metabolism by activating NFκB through MAOA-mediated oxidative stress. Finally, using the mouse intrauterine exposure model, the results confirmed that TPhP induced oxidative stress, activated inflammatory factors, disturbed tryptophan metabolism, and increased the levels of the tryptophan metabolites serotonin, kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid in the placenta during the second trimester of pregnancy. Overall, TPhP can disturb placental tryptophan metabolism by activating the inflammatory factor NFkB, which was induced by MAOA-induced oxidative stress. The results of this study confirm that indirect exposure to xenobiotic compounds at an early life stage can impair offspring development and provide a novel perspective on the neurodevelopmental toxicity of TPhP.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2022
·
IF 5.895
Shanshan Hu,Liyong Luo,Xintong Bian,Rui Hai Liu,Sibo Zhao,Yu Chen,Kang Sun,Jielin Jiang,Zhonghua Liu,Liang Zeng
Pu-erh tea is a healthy beverage rich in phytochemicals, and its effect on the risk of inducing circadian rhythm disorders (CRD) is unclear. In this study, healthy mice were given water or 0.25% (w/v) Pu-erh tea for 7 weeks, followed by a 40 day disruption of the light/dark cycle. CRD caused dysregulation of neurotransmitter secretion and clock gene oscillations, intestinal inflammation, and disruption of intestinal microbes and metabolites. Pu-erh tea boosted the indole and 5-hydroxytryptamine pathways of tryptophan metabolism via the gut–liver–brain axis. Furthermore, its metabolites (e.g., IAA, Indole, 5-HT) enhanced hepatic glycolipid metabolism and down-regulated intestinal oxidative stress by improving the brain hormone release. Tryptophan metabolites and bile acids also promoted liver lipid metabolism and inhibited intestinal inflammation (MyD88/NF-κB) via the enterohepatic circulation. Collectively, 0.25% (w/v) Pu-erh tea has the potential to prevent CRD by promoting indole and 5-HT pathways of tryptophan metabolism and signaling interactions in the gut–liver–brain axis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Hongxia Li,Letong Wang,Simeng Yan,Jinliang Chen,Mengmeng Zhang,Rui Zhao,Xiaohui Niu,Kunjie Wang
Construction of chiral electrochemical sensors for stereoselective recognition is of great significance in medicine and pharmacy. Compared with traditional chiral recognition materials, metal organic frameworks (MOFs) are undoubtedly a new type of materials for chiral recognition. Here, we report a novel MOFs structure (Phe-Cu-PTA) that formed by the metal ion Cu 2+ and organic ligands [1.10-Pheanthroline (Phe), Terephthalic acid (PTA)], which was used to distinguish L-tryptophan and D-tryptophan (L/D-Trp) enantiomers. Differential pulse voltammetry (DPV) test results showed the ability of the Phe-Cu-PTA to recognize the Trp-enantiomers. Owing to the different steric configuration of the L/D-Trp-enantiomers, host (MOFs)-guest (Trp-isomers) interactions are different for L/D-Trp, the peak current values of L-Trp-and D-Trp-are obviously different, thereby effectively distinguishing the Trp-isomers. The results demonstrated that the developed MOFs (Phe-Cu-PTA) showed significantly higher binding force toward D-Trp-than L-Trp. Therefore, the proposed electrochemical chiral interface can be considered as a potential platform for enantiomeric recognition of chiral compounds.
✓ 已验证
产品关联
DOI
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
Heliyon
·
2023
·
IF 4
Habtamu Adefris Abebe,Abebe Diro,Shimeles Addisu Kitte
Herein, we reported carbon paste electrode modified with graphitic carbon nitride (g–C 3 N 4 –CPE) to determine of tryptophan (Trp) using voltametric techniques. Various spectroscopic and electrochemical techniques were used to characterize the as-synthesized g-C 3 N 4 and the assembled electrodes. The transfer coefficient, rate constant and the diffusion coefficient of Trp in this system were found to be 0.28, 1.9 × 10 4 M −1 s −1 and 3.2 × 10 −5 cm 2 s −1 , respectively. The linear range was obtained for the detection of Trp using LSV is from 0.1 μM to 120 μM at pH 5. The limit of detection (LOD) (3σ/ m ) was 0.085 μM. The demonstrated modified CPE was also effectively used for the detection of Trp in milk with percentage recovery of 98 %–105.2 %. Furthermore, the modified CPE exhibited good repeatability, reproducibility and appropriate selectivity.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）