JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Chen Xin,Wang Qing-wan,Zhan Tong-ling,Sun Yue,Zhang Xiao-rui,Liu Kun,Liu Xiao-wu
Nitrogen@Carbon quantum dots (N@CQDs) are prepared using microwave hydrothermal method, and polyvinylpyrrolidone (PVP) and melamine are used as mixed C source and N source. Microwave reaction conditions of preparing the N@CQDs are 170 ℃ and 3 h. This N@CQDs are are used as fluorescence probe for detection of amino acids. The N@CQDs can recognize L-alanine in water solution, and simultaneously recognize both L-methionine and L-cysteine in dimethyl sulfoxide (DMSO) solution. The linear ranges for L-alanine, L-methionine and L-cysteine are 0–15 µM, 2–50 µM and 0–17 µM, respectively. While limits of detection (LOD) for them are 11.092 nM, 7.8067 nM and 0.67476 nM, respectively. Compared to presently available detection methods, as-prepared N@CQDs have the advantage of high sensitivity and selectivity. Furthermore, coexistence of other amino acids has minimal interference in the detection of L-alanine, L-methionine and L-cysteine. For the as-prepared N@CQDs, solvent plays important roles in influencing the identification of amino acid types and detection sensitivity.
研究领域:
分析化学
·
生物传感
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CyTA-Journal of Food
·
2019
·
IF 1.605
Tong Shi,Li Yuan,Jianlou Mu,Ruichang Gao
Amino acids containing L-Arginine (Arg), L-Lysine (Lys) and L-Histidine (His) are recognized to increase the solubility of myosin at low ionic strength, but there is a difference in the researchers’ views on their effects on the secondary structure of myosin. To elucidate which method is relatively appropriate for the determination of secondary structures of myosin added with Arg, Lys or His, Circular dichroism (CD) spectra and Raman spectroscopy were carried out respectively. Raman spectroscopy was more suitable than CD method for determination of the secondary structures of myosin added with His, while CD spectra was more accurate for the myosin samples added with Lys and the adequate concentration of Lys should be under 10 mM. Both CD and Raman methods could be applied to myosin added with Arg, however, the latter was recommended and the adequate additive content of Arg in CD method should be less than 10 mM.
研究领域:
生物化学
·
分子生物学
·
蛋白质研究
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Linlin Wang,Lilong Wang,Cui Cao,Jun Zhao,Chen Song,Zhijie Bao,Chunhong Yan,Shuang Song
Excessive protein consumption (EPC) could increase the gastrointestinal burden and impair gut motility. The present study was designed to explore the improvement of chitosan (CTS) and chitosan oligosaccharide (COS) on colonic motility and serum metabolites in rats after EPC. The results of in vivo experiments fully proved that CTS and COS could improve gut motility and reverse the serum metabolites in rats as indicated by LC-MS/MS analysis, and the COS group even showed a better effect than the CTS group. Furthermore, short-chain fatty acids (SCFAs), which could promote gut motility, were also increased to alleviate EPC-induced constipation after supplementation with CTS or COS. In addition, CTS and COS could decrease the concentration of ammonia in serum and down-regulate the levels of H 2 S and indole. In summary, the present study revealed that CTS and COS could produce SCFAs, improve the colonic motility in rats, reverse the levels of valine , adenosine, cysteine, 1-methyladenosine, indole, and uracil , and enhance aminoacyl-tRNA biosynthesis and valine, leucine and isoleucine degradation. The present study provides novel insights into the potential roles of CTS and COS in alleviating the adverse effects of EPC.
研究领域:
营养学
·
胃肠病学
·
代谢组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2013
·Vol. 14
·期 12
·23751-23761
·
IF 2.464
Jun Xiang,Yugang Jiang
Our present study aimed to determine the antiepileptic activity of matrine, and explore the possible molecular mechanism. To evaluate the antiepileptic activity of matrine, seizures in mice induced by PTZ and MES were established, then the pentobarbital sodium-induced anaesthetizing time and locomotor activity tests in mice were also carried out. For the molecular mechanism investigations, contents of aspartic acid (Asp), gamma-aminobutyric acid (GABA), glutamic acid (Glu), glycine (Gly) in seizures mice were determined; then, the chronic seizures rats induced by PTZ were prepared, and western blotting was used to determine the expressions of GAD 65, GABAAand GABABin the brains. In the results, matrine showed significant antiepileptic effects on seizures mice induced by MES and PTZ. Moreover, the pentobarbital sodium-induced anaesthetizing time and locomotor activity tests were also demonstrated that matrine had obvious antiepileptic effects. Additionally, our results revealed that after treatment with matrine, contents of GABA can be elevated, and the contents of Glu were obviously decreased. Furthermore, western blotting revealed that the mechanism regarding the antiepileptic effect of may be related to the up-regulations of GAD 65 and GABAAin the brain. Collectively, we suggested that matrine can be developed as an effective antiseptic drug.Keywords:antiepileptic;matrine;gamma-aminobutyric acid;glutamic acid
研究领域:
药理学
·
神经科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER JOURNAL
·
2016
·Vol. 48
·期 7
·807-812
·
IF 1.629
Yang Yong,Sun Chen,Zhou Yuming,Wang Tianhe,Zhang Yiwei
Optically active polyurethane (OPU) and racemic polyurethane (RPU) derived from chiral and racemic tyrosine were synthesized using a hydrogen transfer addition polymerization procedure. The structural and optical properties of the polyurethanes were systematically investigated using Fourier transform infrared spectroscopy, 1 H NMR, gel permeation chromatography (GPC), UV-vis spectroscopy, circular dichroism spectroscopy, thermogravimetric analysis (TGA) and X-ray diffraction techniques. In contrast to RPU, OPU possesses a single-handed helical conformation and optical activity owing to the induced asymmetric force field in the chiral monomer. This regular secondary structure facilitates the formation of numerous interchain hydrogen bonds, which increases the crystallinity and thermal stability of OPU. The high-temperature infrared spectroscopy results indicate that the hydrogen bonding collapses before thermal decomposition. In contrast to the intense infrared emissivity property of random coiled RPU, both helical stereostructures and hydrogen bonding contribute to decreasing this emissivity for OPU.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2021
·Vol. 45
·期 10
·e15821
·
IF 2.19
Qun Huang,Hanliang Song,Yonggui Pan,Zhengke Zhang
Papaya fruit is easily affected by low temperature, causing chilling injury (CI). In this study, the exogenous arginine was applied in the storage of postharvest papaya fruit and it was found that 0.8 mM arginine treatment significantly alleviated CI of papaya fruit. Arginine treatment promoted the accumulation of polyamines (PAs), which might be ascribed to the increased activities of arginase, arginine decarboxylase (ADC), ornithine decarboxylase (ODC), and S-adenosylmethionine decarboxylase (SAMDC). A higher accumulation of proline was found in arginine-treated papaya fruit, which may be due to increased activity of ornithine-δ-aminotransferase (OAT) and Δ 1 -pyrroline-5-carboxylate acid synthase (P5CS) and inhibited activity of proline dehydrogenase (PDH). In addition, arginine treatment increased higher nitric oxide synthase (NOS) activity and promoted the generation of nitric oxide (NO). The results of this study indicate that exogenous arginine may improve the chilling tolerance of postharvest papaya fruit by regulating arginine and proline metabolism. Practical applications In recent years, chilling injury of tropical fruits is a significant problem, including papaya. Many studies on polyamine, proline, nitric oxide, and chilling injury of fruits, but arginine, as a common precursor of polyamine, proline, and nitric oxide, are rarely studied, especially in papaya fruit. Our findings demonstrated that the exogenous arginine can regulate endogenous arginine metabolism, induce polyamine, putrescine, and nitric oxide accumulation, and coordinate to alleviate chilling injury of papaya fruit.
研究领域:
植物生理学
·
园艺学
✓ 已验证
产品关联
DOI
高影响因子
Thermal Science and Engineering Progress
·
2023
·
IF 4.8
Shuai Guo,Guoliang Qi,Jialiang Gao,Deng Zhao,Kaixin Chen,Chenchen Zhao,Xingcan Li,Guangyu Li
Pyrolysis is an effective method for safely disposing of sewage sludge via conversion into a usable energy source. However, municipal sludge has a high protein content, which is a major source of NO x precursors. This study investigated the effect of CaO on NO x precursor formation during glutamate pyrolysis and demonstrated that CaO occupies the carbo x yl site of glutamic acid at 320 °C, which delays its decomposition and promotes the conversion of glutamic acid from a five- to a si x -membered ring. At 400 °C, heterocyclic nitrogen in the tar peaked from 4.87 to 53.87% after adding CaO. As the temperature increases to 480 °C, CaO might promote the conversion of heterocyclic nitrogen into tricyclic piperazine dione in the tar, which subsequently decomposed to produce HCN in large quantities. At 480 °C, CaO contributed to the decrease in pyrrole, pyridine, and quaternary nitrogen in the semi-coke from 24.81%, 12.93%, and 7.43% to 1.91%, 5.97%, and 1.43%, respectively and promoted HCN hydrolysis to form NH 3 . At 480–680 °C, CaO interacted with NH 3 to form CaCN 2 . The product of CaC x N y decomposition—CaC x —captured NH 3 . At high temperatures, CaO inhibited HCN release, which might be related to the reaction between CaO and HCN to form CaC x N y , subsequently reconverted into CaO at temperatures above 680 °C. These findings provide novel insights into the influence of CaO on amino acid pyrolysis to produce NO x precursors and the regulation of NO x precursor production.
研究领域:
环境科学
·
能源与燃料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 16
·9421-9426
·
IF 10.7
Yaxin Wang,Yajie Zhou,Shanshan Zhao,Mingjiang Zhang,Anqi Li,Guangen Li,Qi Guo,Xueru Guo,Zhi Tong,Zeyi Li,Jing Lin,Taotao Zhuang
Chiral amino acids are crucial for humans, and their recognition can provide information for pharmaceutical quality and clinical diagnosis. Histidine (His) and tryptophan (Trp), for example, have a close association with nephropathy and are extensively utilized in the pharmaceutical field. However, efficiently distinguishing these two amino acids and their configurations is still in its infancy, requiring the development of a practical, cost-effective, and reliable detection method. Herein, we disclose a dual-optical-response recognition system, composed of 9-aminoacridine and cellulose nanocrystals, that can stepwise recognize His/Trp and their enantiomers based on photoluminescence and circular dichroism (CD) analysis. Amino acids cause variation in the fluorescence intensity of the DOR system, while their enantiomers give distinctive shifts in CD spectra. This study achieves a stepwise recognition of chiral amino acids, paving a new way for drug screening and clinical diagnosis.
研究领域:
生物化学
·
药物分析
·
临床诊断
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LIQUID CHROMATOGRAPHY & RELATED TECHNOLOGIES
·
2017
·
IF 0.697
Yanni Miao,Qi Liu,Wei Wang,Li Liu,Li Wang
A new chiral capillary electrophoresis (CE) analytical method for the determination of six pairs of amino acid enantiomer-derivatized precapillary with 9-fluorenylmethoxycarbonyl chloride (FMOC) was developed. CE separation parameters such as the pH of background electrolyte, the boric acid concentration, the addition of D-fructose and isopropanol, and the effect of new binary chiral selectors on the electropherograms were investigated. Precapillary and in-capillary derivatization was compared as well. The results showed that enantiomeric separations were obtained with enantio-resolution (Rs) ranged from 2.61 to 9.99 for the FMOC-derivatized amino acid enantiomers except alanine with Rs 1.06. Precapillary derivatization method provides overall better Rs for nearly all the targets except FMOC-aspartate with efficiency up to 1.309 × 106 plates and limit of detection (LOD) down to 2.5 μM. This method was successfully applied to analyze the concentration of the D/L-glutamic acid and D/L-aspartate in seven rice wine samples.
研究领域:
分析化学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2022
·Vol. 44
·期 5
·635-642
·
IF 2.716
Liu Jia,Liu Jianmin,Yang Bin,Gao Cong,Song Wei,Hu Guipeng,Liu Liming,Wu Jing
Objectives This study aimed to develop an efficient enzymatic strategy for the industrial production of phenylpyruvate (PPA) from l -phenylpyruvic acid ( l -Phe). Results l -amino acid deaminase from Proteus mirabilis was expressed in Escherichia coli BL21 (DE3) and modified to release product inhibition by employing conformational dynamics engineering. Based on structural analysis, two residues (E145/L341) were identified for reducing interactions between the product and enzyme and increasing flexibility of the protein, thereby facilitating the product release. The mutant M2 E145A/E341A exhibited a 3.84-fold reduction in product inhibition and a 1.35-fold increase in catalytic efficiency in comparison to the wild type. Finally, 81.2 g/L PPA production with a conversion of 99.6% was obtained in a 5-L bioreactor. Conclusions The engineered catalyst can significantly reduce product inhibition and facilitate the effective industrial synthesis of PPA.
研究领域:
生物化学
·
工业微生物学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY
·
2017
·
IF 2.313
Xiaoyan Zhao,Liqing Wang,Hao Zhang,Duoduo Zhang,Zhihao Zhang,Jie Zhang
The liver disease related to chronic alcohol consumption is one of the leading causes of death for alcoholics. The efficient drug to ameliorate the alcoholic liver injury was needed urgently. The present study was performed to investigate whether artemisinin possessed the protective effect against chronic alcohol consumption. 50 male Kunming mice were divided into 5 groups: control group (C): 10 ml/kg saline + 10 ml/kg saline, alcohol group (A): 10 ml/kg 56%(v/v) alcohol + 10 ml/kg saline, low dose group of artemisinin (L): 10 ml/kg 56%(v/v) alcohol + 30 mg/kg/day artemisinin, medium dose group of artemisinin (M): 10 ml/kg 56%(v/v) alcohol + 60 mg/kg/day artemisinin, high dose group of artemisinin (H): 10 ml/kg 56%(v/v) alcohol + 120 mg/kg/day artemisinin. Drugs were given orally every day. The general state of mice was observed and the levels of serum activities of AST and ALT were detected after treatment with drugs for 30 days. Besides, the liver weight index was calculated and histopathological analysis was performed. We successfully demonstrated that treatment with high dose of artemisinin significantly decreased the elevated levels of AST ( p < 0.05 ) and ALT ( p < 0.01 ) in plasma, as well as the liver weight index ( p < 0.01 ). The loss of body weight, tissue injury, oedema and inflammatory cell infiltration in the hepatocytes were found in the A group. These symptoms were remarkably alleviated in animals treated with artemisinin. Artemisinin can inhibit the activation of NF-кB and the expression of inflammatory cytokines inducible nitric oxide synthase. Besides, it can also enhance the stability of liver cell membrane, and reduce the damage of liver cell membrane and liver cell. Artemisinin showed a protective effect against chronic alcohol poisoning and it has a great potential for the clinical application to treat the liver injury induced by alcohol.
研究领域:
药理学
·
肝病学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 104
·期 23
·10005-10018
·
IF 3.53
Guo Xiaolei,Wu Weibin,Zhang Mingliang,Wu Licheng,Huang Jianzhong
Abstract l -Tyrosine is a versatile compound used in the fine chemical, pharmaceutical, and functional food industries. Here, we report a bi-enzymatic cascade involving alanine racemase (ALR) and d -amino acid oxidase (DAAO) to produce pyruvate, as co-substrate for l -tyrosine production, from the cheap substrate l -alanine. The BpALR (ALR from Bacillus pseudofirmus ) was used as a whole-cell biocatalyst, converting l -alanine to d , l -alanine. The FsDAAO (DAAO from Fusarium solani ) was immobilized to oxidize the d -alanine generated in the first step to pyruvate. Both systems were combined as a continuous-flow reactor for maximized l -alanine-to-pyruvate conversion rates. The optimal parameters and appropriate conditions for FsDAAO immobilization were investigated. The pyruvate concentration of 86.6 g/L was achieved within 17 h. Subsequently, a whole-cell biocatalyst system for l -tyrosine production, catalyzed by the tyrosine phenol-lyase (TPL) from Erwinia herbicola (EhTPL), was developed, and a fed-batch approach was applied with phenol and the pyruvate produced with the ALR/DAAO system mentioned above. The concentration of phenol and pyruvate in the reactor should not exceed 7.5 g/L and 10 g/L, respectively. Significantly, the l -tyrosine concentration of 152.5 g/L was achieved within 10 h, demonstrating the great potential for high-efficiency production of l -tyrosine through the approach we established in this paper. Graphical abstract Key points • A specific bioreactor system for pyruvate produced from l -alanine was developed • The appropriate condition for immobilization of FsDAAO was investigated • A fed-batch process was established to produce l -tyrosine with recombinant E. coli • The bi-enzymatic cascade was successfully used for l -tyrosine production at low cost
研究领域:
生物技术
·
生物化学
·
化工工程
·
药学
✓ 已验证
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）