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Food Science and Human Wellness 2024年第2期13卷 879-884页

作者： Xin Wang Chengyi Hong Zhengzhong Lin Zhiyong Huang College of Ocean Food and Biological Engineering Jimei UniversityXiamen 361021China

A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.

关键词： Co doped g-C_(3)N_(4) Ratiometric fluorescent probe hypoxanthine Freshness Aquatic products

On-line electrochemical measurements of cerebral hypoxanthine of freely moving rats

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Science China Chemistry 2009年第10期52卷 1677-1682页

作者： ZHANG ZiPin LIN YuQing MAO LanQun Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing 100190China

This study demonstrates an on-line method for continuous measurements of cerebral hypoxanthine in the freely moving rats with integration of selective electrochemical biosensing with in vivo microdialysis sampling. The selective electrochemical biosensing is achieved by using xanthine oxidase (XOD) as the specific sensing element and Prussian blue (PB) as the electrocatalyst for the reduction of H2O2 generated from the oxidase-catalyzed reaction. The method is virtually interference-free from the co-existing electroactive species in the brain and exhibits a good stability and reproducibility. Upon integrated with in vivo microdialysis, the on-line method is well suitable for continuous measurements of cerebral hypoxanthine of freely moving rats, which is illustrated by the measurements of the microdi-alysates after the hypoxanthine standard was externally infused into the rat brain. This study essentially offers a facile on-line electrochemical approach to continuous measurements of cerebral hypoxanthine and could find some interesting applications in physiological and pathological investigations associated with hypoxanthine.

关键词： on-line method electrochemical biosensor hypoxanthine rat brain

Fluorescent Copper Nanoclusters for Highly Sensitive Monitoring of hypoxanthine in Fish

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Journal of Analysis and Testing 2021年第1期5卷 76-83页

作者： Zi-Xuan Zhao Ya-Ping Guo Jie Wei Quan-Sheng Chen Xiao-Mei Chen College of Food and Biological Engineering Jimei UniversityXiamen 361021China School of Food and Biological Engineering Jiangsu UniversityZhenjiang 212013China

hypoxanthine(Hx)is an important freshness indicator reflecting the initial freshness of aquatic products.In this work,a novel fluorescence method was established based on cysteine functionalized copper nanoclusters(Cys-CuNCs)for monitoring Hx in fish.The as-synthesized Cys-CuNCs exhibit favorable fluorescent property.Importantly,the fluorescence can be quenched significantly when the solution contained a small amount of hydrogen peroxide(H_(2)O_(2)),which was due to both the oxidation of H_(2)O_(2) towards Cys-CuNCs and the resulting Cu(II).Owing to that Hx can generate H_(2)O_(2) under dissolved oxygen and xanthine oxidase(XOD),a fluorescent method for Hx was established.Under the optimal conditions,the Hx concentration in the range of 8–400μmol/L has a good linear relationship with the fluorescence quenching e fficiency,and the detection limit is 0.7μmol/L.Finally,the as-established sensor was applied to determine Hx content in carp.By comparing to the total volatile basic nitrogen(TVB-N)results,the proposed method was feasible in the evaluation of carp freshness.

关键词： Copper nanoclusters hypoxanthine Freshness Fluorescence Fish

Electrocatalytic Oxidation and Simultaneous Determination of Uric Acid,Xanthine,hypoxanthine and Dopamine Based on β-Cyclodextrin Modified Glassy Carbon Electrode

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Chemical Research in Chinese Universities 2012年第6期28卷 1047-1053页

作者： GONG Wei DOU Zhi-yu CUI Li-li LIU Da-jun HE Xing-quan Department of Chemistry and Chemical Engineering Changchun University of Science and Technology Changchun 130022 P. R. China

A novel covalently modified glassy carbon electrode with β-cyclodextrin was prepared via electropolymerization technique for the simultaneous determination of uric acid（UA）,xanthine（XA）,hypoxanthine（HX） and dopamine（DA）.This new electrode presented an excellent electrocatalytic activity towards the oxidation of UA,XA,HX and DA by cyclic voltammetry（CV） method.The oxidation peaks of the four compounds were well defined and had the enhanced peak currents.The separation potentials of the oxidation peaks for DA-UA,UA-XA and XA-HX were 150,390 and 360 mV in CV,respectively.By means of differential pulse voltammetry（DPV） method,the calibration curves in the ranges of 10―225,5―105,10―170 and 5―150 μmol/L were obtained for UA,XA,HX and DA,respectively.The lowest detection limits（S/N=3） were 5,1.25,5 and 1.5 μmol/L for UA,XA,HX and DA,respectively.The practical application of the modified electrode was demonstrated by the determination of DA in hydrochloride injection and UA,XA,HX in human urine samples.

关键词： β-Cyclodextrin Uric acid Xanthine hypoxanthine Dopamine

Utility of cardiac biomarkers in sports medicine:Focusing on troponin,natriuretic peptides,and hypoxanthine

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Sports Medicine and Health Science 2020年第2期2卷 65-71页

作者： Anirban Mahanty Lei Xi Pauley Heart Center Department of Internal MedicineVirginia Commonwealth UniversityRichmondVAUSA

Evidence-based consensus suggests that physical activity and regular exercise training can reduce modifiable risk factors as well as rate of mortality and morbidity in patients with chronic diseases,such as cardiovascular disease(CVD),diabetes,obesity and cancer.Conversely,long-term exercise training and drastic increase in vigorous physical activity may also cause acute cardiovascular events(e.***.acute myocardial infarction)and deleterious cardiac remodeling,particularly when exercise is performed by unfit or susceptible individuals.There is a reversed J-shaped hormesis-like curve between the duration and intensity of exercise and level of CVD risks.Therefore,it is important for an early detection of cardiac injuries in professional and amateur athletes.Under this context,this article focuses on the use of biomarker testing,an indispensable component in the current clinical practices especially in Cardiology and Oncology.We attempt to justify the importance of using circulating biomarkers in routine practices of Sports Medicine for an objective assessment of CVD events following exercise.Special attentions are dedicated to three established or emerging cardiac biomarkers(i.***.cardiac troponins,natriuretic peptides,hypoxanthine)for myocardial tissue hypoxia/ischemia events,muscle stress,and the consequent cellular necrotic injury.Based on these focused analyses,we propose use of circulating biomarker testing in both laboratory and point-of-care settings with an increasingly broader involvement or participation of team physicians,trainers,coaches,primary care doctors,as well as educated athlete community.This diagnostic approach may improve the quality of medical surveillance and preventive measures on exercise-related CVD risks/outcomes.

关键词： Biomarker Cardiac troponin Exercise hypoxanthine Natriuretic peptide Overtraining syndrome Tissue ischemia Risk factors

A Novel Flow Injection Optical Fiber Biosensor for hypoxanthine Based on Luminol Electrochemiluminescence

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Chemical Research in Chinese Universities 2003年第2期19卷 240-244页

作者： LI Ying xiu ZHU Lian de ZHU Guo yi State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022P.R.China

IntroductionIn the food industry,the determination of hy-poxanthine in fish meat can be regarded as a simple method for evaluating fish freshness.……

关键词： Electrochemiluminescence Flow injection Optical fiber biosensor Sol-gel Ceramic-carbon composite electrode hypoxanthine Fish freshness

CAPILLARY　ELECTROPHORESIS　DETERMINATION　OF　INOSINE　IN　SOMEDRUG　FORMULAE　USING　hypoxanthine　AS　INTERNAL　STANDARD

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Chinese Chemical Letters 1995年第8期

ＣＡＰＩＬＬＡＲＹＥＬＥＣＴＲＯＰＨＯＲＥＳＩＳＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＩＮＯＳＩＮＥＩＮＳＯＭＥＤＲＵＧＦＯＲＭＵＬＡＥＵＳＩＮＧＨＹＰＯＸＡＮＴＨＩＮＥＡＳＩＮＴＥＲＮＡＬＳＴＡＮＤＡＲＤ￥ＹｏｎｇＣＨＥＮ... 详细信息

ＣＡＰＩＬＬＡＲＹＥＬＥＣＴＲＯＰＨＯＲＥＳＩＳＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＩＮＯＳＩＮＥＩＮＳＯＭＥＤＲＵＧＦＯＲＭＵＬＡＥＵＳＩＮＧＨＹＰＯＸＡＮＴＨＩＮＥＡＳＩＮＴＥＲＮＡＬＳＴＡＮＤＡＲＤ￥ＹｏｎｇＣＨＥＮ；ＺｈｕｏＢｉｎＹＵＡＮ（Ｇｒａｄ...

关键词： AS hypoxanthine INTERNAL STANDARD USING CAPILLARY DETERMINATION

Disposable amperometric biosensors based on xanthine oxidase immobilized in the Prussian blue modified screen-printed three-electrode system

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Science China Chemistry 2010年第12期53卷 2581-2586页

作者： TENG YuanJie,CHEN Chen,ZHOU ChangXiang,ZHAO HongLi & LAN MinBo Shanghai key Laboratory of Functional Materials Chemistry Research Center of Analysis Test,East China University of Science and Technology,Shanghai 200237,China Shanghai key Laboratory of Functional Materials Chemistry Research Center of Analysis Test East China University of Science and Technology Shanghai China

The screen-printed three-electrode system was applied to fabricate a new type of disposable amperometric xanthine oxidase biosensor.Carbon-working,carbon-counter and Ag/AgCl reference electrodes were all manually printed on the polyethylene terephthalate substrate forming the screen-printed three-electrode system by the conventional screen-printing process.As a mediator,Prussian blue could not only catalyze the electrochemical reduction of hydrogen peroxide produced from the enzyme reaction,but also keep the favorable potential around 0 V.The optimum operational conditions,including pH,potential and temperature,were investigated.The sensitivities of xanthine and hypoxanthine detections were 13.83 mA/M and 25.56 mA/M,respectively.A linear relationship was obtained in the concentration range between 0.10μM and 4.98μM for xanthine and between 0.50μM and 3.98μM for hypoxanthine.The small Michaelis-menten constant value of the xanthine oxidase biosensor was calculated to be 3.90 μM.The results indicate that the fabricated xanthine oxidase biosensor is effective and sensitive for the detection of xanthine and hypoxanthine.

关键词： xanthine oxidase xanthine hypoxanthine screen-printed three-electrode system Prussian blue

Determination of gouty arthritis' biomarkers in human urine using reversed-phase high-performance liquid chromatography

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Journal of Pharmaceutical Analysis 2014年第2期4卷 153-158页

作者： Lei-Wen Xiang Jing Li Jin-Ming Lin Hai-Fang Li Beijing Key Laboratory of Microanalysis Methods and Instrumentation Department of ChemistryTsinghua University Institute of Food and Fermentation Industries Fuqing Branch of Fujian Normal University

Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in urine based on reversed-phase high-performance liquid chromatography （RP-HPLC） with ultraviolet （UV） detector was proposed. After pretreatment by dilution, centrifugation and filtration, the biomarkers in urine samples were separated by ODS-BP column by elution with methanol/50 mM NaH2PO4 buffer solution at pH 5.26 （5：95）. Good linearity between peak areas and concentrations of standards was obtained for the biomarkers with correlation coefficients in the range of 0.9957-0.9993. The proposed analytical method has satisfactory repeatability （the recovery of data in a range of creatinine, uric acid, hypoxanthine and xanthine was 93.49-97.90%, 95.38-96.45%, 112.46-115.78%and 90.82-97.13%with standard deviation of o5%, respectively） and the limits of detection （LODs, S/N Z 3） for creatinine, uric acid, hypoxanthine, and xanthine were 0.010, 0.025, 0.050 and 0.025 mg/L, respectively. The established method was proved to be simple, accurate, sensitive and reliable for the quantitation of gouty arthritis＇ biomarkers in human urine samples. The ratio of creatinine to uric acid was found to be a possible factor for assessment of gouty arthritis.

关键词： Gouty arthritis Creatinine Uric acid hypoxanthine Xanthine High-performance liquid chromatography

X-Ray Induced Mutation Frequency at the <i>hypoxanthine Phosphoribosyltransferase</i>Locus in Clinically Relevant Radioresistant Cells

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2017年第4期6卷 377-391页

作者： Yoshikazu Kuwahara Mehryar Habibi Roudkenar Yusuke Urushihara Yohei Saito Kazuo Tomita Amaneh Mohammadi Roushandeh Tomoaki Sato Akihiro Kurimasa Manabu Fukumoto Division of Radiation Biology and Medicine Faculty of Medicine Tohoku Medical and Pharmaceutical University Sendai Japan Department of Applied Pharmacology Graduate School of Medical and Dental Sciences Kagoshima University Kagoshima Japan Medical Biotechnology Research Center Paramedicine Faculty Guilan University of Medical Science Rasht Iran Fukushima Project Headquarters National Institute for Quantum and Radiological Science and Technology Fukushima Japan Department of Radiopharmacy Faculty of Pharmaceutical Science Tohoku Medical and Pharmaceutical University Sendai Japan Department of Anatomical Sciences School of Medicine Hamadan University of Medical Sciences Hamadan Iran Department of Molecular Pathology Tokyo Medical University Tokyo Japan

To elucidate the molecular mechanisms underlying cellular radioresistance, clinically relevant radioresistant cell lines were established via long-term exposure to X-rays with stepwise dose escalation. Established cells continue to proliferate despite exposure to 2 Gy X-rays/day for more than 30 days, a standard protocol in cancer radiotherapy. DNA repair fidelity in radioresistant and the parental cells by evaluating the mutation frequency at the hypoxanthine phosphoribosyltransferase (HPRT) locus after exposure to X-rays was determined. Mutation spectrum at the HPRT locus was examined by multiplex polymerase chain reaction. Rejoining kinetics of X-ray-induced DNA double strand breaks (dsbs) was evaluated by the detection of phosphorylated histone H2AX (γH2AX) after X-irradiation. The fold increase in the HPRT mutation frequency due to acute radiation was similar between radioresistant and the parental cell lines. However, fractionated radiation (FR) consisting of 2 Gy X-rays/day increased the mutation frequency at the HPRT locus in parental but not in radioresistant cells. Analysis of the FR-induced mutations at the HPRT locus revealed a high frequency of deletion mutations (>70%) in parental but not in radioresistant cells. As assessed by γH2AX immunostaining, DNA dsbs induced by acute exposure to 10 Gy of X-rays were repaired to the control level within 7 days in radioresistant but not in the parental cells. Moreover, 2 Gy × 5 FR increased the number of γH2AX-positive cells in parental cultures but not in radioresistant cultures. DNA dsbs induced by 2 Gy/day FR are repaired with fidelity in radioresistant but not in parental cells.

关键词： Clinically Relevant Radioresistant (CRR) Cell hypoxanthine Phosphoribosyltransferase (HPRT) Mutation Frequency Phosphorylated Histone H2AX (γH2AX) X-Rays