N-乙酰氨基葡萄糖化在信号转导中的作用

蛋白质磷酸化在生命活动及信号转导过程中的重要作用已经被研究证实,但不少研究发现在大多数核、胞液蛋白质上不仅存在磷酸化动态修饰,还存在广泛的动态N-乙酰氨基葡萄糖修饰。N-乙酰氨基葡萄糖基转移酶和N-乙酰氨基葡萄糖基酶以类似于蛋白激酶和磷酸酶的方式调节蛋白质是否发生N-乙酰氨基葡萄糖化。N-乙酰氨基葡萄糖化蛋白质主要分布在细胞核与胞液,其生理功能涉及细胞基本生命活动和调节信号传递。N-乙酰氨基葡萄糖的作用基础与阻断或影响蛋白质的磷酸化有关。

复方醋酸钠林格注射液中无水葡萄糖含量测定方法的建立及葡萄糖转化现象的探讨

目的建立复方醋酸钠林格注射液中无水葡萄糖含量测定方法,并针对方法建立中发现的葡萄糖转化问题开展研究。方法采用氨基硅烷键合硅胶为填充剂的色谱柱;以乙腈-水-氨水(体积比75∶25∶0.1)为流动相;示差折光检测器检测;流速为1.0 mL/min,柱温和检测池温度均为40℃。结果无水葡萄糖浓度在0.4125~8.249 mg/mL范围内线性关系良好(r=1.0000),定量限为101μg/L,平均回收率为100.5%,RSD为0.5%,采用该测定法发现样品中少量葡萄糖转化为果糖。结论建立的方法简单、准确、灵敏度高,不受葡萄糖转化现象的干扰,适用于复方醋酸钠林格注射液中无水葡萄糖的含量测定。

大米饮料制备工艺研究

利用糙米和精米经烘炒、生物酶解、过滤、罐装、包装等工序制造色泽清亮、香气宜人、保留糙米和精米原有成分的甘甜可口的大米饮料。对烘烤时间及水解条件等关键工序作了较为系统的研究,大米最佳烘烤条件:白米190℃、20min效果较好,糙米180℃、20min。最佳水解条件为蛋白水解酶2%,葡萄糖化酶125U/g,温度50℃,时间7h。

糖基化血红蛋白不同组分对冠心病的临床价值

目的探讨糖基化血红蛋白不同组分对冠心病发病的临床价值。方法217例患者分为冠心病组(Ⅰ组,60例),冠心病非急性冠脉综合征(ACS)合并糖尿病组(Ⅱ组,60例),ACS合并糖尿病组(Ⅲ组,97例)3组,同期58例健康体检者为对照组。检测果糖糖化血红蛋白(HbA1a)、乳糖糖化血红蛋白(HbA1b)、葡萄糖糖化血红蛋白(HbA1c)、血红蛋白P3组分(HbP3)、血红蛋白A0组分(HbA0)、不稳定糖化血红蛋白(LA1c/CHb1)和抗碱血红蛋白(HbF),并对各组参数进行比较。应用Logistic回归分析冠心病及冠心病合并糖尿病的影响因素,并采用ROC曲线分析比较各影响因素的诊断效能。结果Ⅰ组、Ⅱ组与Ⅲ组的HbA1b、HbA1c、HbP3和HbA0与对照组比较差异有统计学意义(P<0.01或P<0.05),Ⅱ组与Ⅲ组比较,糖基化血红蛋白各参数差异f无统计学意义(P>0.05)。Logistic逐步回归及ROC曲线分析显示,HbA1c、HbP3是冠心病的影响因素且具有一定的诊断效能。HbA1c、HbP3在Ⅱ组、Ⅲ组的ROC曲线效能基本一致。结论HbA1b、HbA1c、HbP3和HbA0与冠心病及冠心病合并糖尿病关系密切。HbA1c和HbP3是冠心病的影响因素且具有一定的诊断效能。

金丝桃素在大鼠体内的代谢产物

分离鉴定金丝桃素在大鼠胆汁中的代谢产物以及在坏死肝脏组织中的存在形式。正常大鼠和肝脏缺血再灌注损伤模型大鼠经静脉注射10 mg/kg金丝桃素后,收集正常大鼠0～12 h胆汁以及坏死模型大鼠24 h坏死肝脏组织,对生物样品预处理后,采用高效液相色谱-高分辨飞行时间质谱（HPLC-TOF/MS）联用技术进行分析。在大鼠胆汁中鉴定出金丝桃素原形（M0）和3个葡萄糖化代谢产物（M1、M2、M3）,而在坏死肝脏组织中仅鉴定出金丝桃素原形。结果表明,金丝桃素在大鼠胆汁中主要以原形和葡萄糖化形式存在,在坏死组织中主要以原形存在。

Efficient production of 5-hydroxymethylfurfural from hexoses using solid acid SO_4^(2-)/In_2O_3-ATP in a biphasic system

A natural attapulgite （ATP）‐based catalyst, sulfated In2O3‐ATP （SO42-/In2O3‐ATP）, was obtained by an impregnation‐calcination method and was used to efficiently and selectively produce the useful platform chemical 5‐hydroxymethylfurfural （HMF） from hexoses. Some important reaction param‐eters were studied, revealing that Lewis and Br-nsted acid sites on SO42-/In2O3‐ATP catalyze glu‐cose isomerization and fructose dehydration. The yields of HMF from glucose and fructose were 40.2%and 46.2%, respectively, using the optimal conditions of 180℃ for 60 min with 10 wt%of solid acid catalyst in a mixture of γ‐valerolactone‐water （9：1）.

用电子束辐射法制备固定化乳酸脱氢酶

前言固定化酶的制备,近年来已有许多进展.固定化技术之一的凝胶格子包埋法,尤其受到重视,因为它与其它方法不同,酶分子本身在固定化过程中几乎完全不发生结合或偶联反应,而是被包埋在凝胶的微细格子里.这样,它可能对酶蛋白的构象。

Genome-wide Analysis of Glucose-6-phosphate Dehydrogenase(G6PDH) and Its Evolution in Eucalyptus grandsis

[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phylogenetic tree of G6PDH gene were analyzed by BLAST and other bioinformatics software within Eucalyptus grandsis whole genome database.[Result] Six G6PDH genes,including one cytomic type and five plastids,were detected in the E.grandsis genome.All the G6PDHs have conserved motifs of motif 1,motif 2,motif 3,motif 7,motif 9 and motif 11.Furthermore,promoter sequences of all E.grandsis G6PDH contain TATA box,enhancer,light-responsive,hormone-responsive and stress-responsive regulatory elements.[Conclusion] This study provided reference for the further revealing molecular function of E.grandsis G6PDH gene family

Use of Glucosyl 3,5-Dinitrobenzoate in Synthesis of Glucosides and Related Oligosaccharides

To investigate a new glycosylation method. Methods In the presence of TMSOTfas catalyst, 1-O-(3, 5-dinitrobenzoyl)-2, 3, 4, 6-tetra-O-benzyl-α-D-glucopyranose 1 reacted with aseries of carboxylic acid, phenols, alcohols and saccharides respectively to give the correspondingglycosylation products. The compounds were determined by ~1H NMR and ^(13)C NMR spectra. ResultsThe α-glu-co-pyranosides and related oligosaccharides were prepared in high yields. Conclusion The3, 5-dinitro-benzoyl group was found to be a good leaving group at the anomeric position andO-glucopyranosides and oligosaccharides were stereoselectively synthesized in good yield.

Antitumor activities of D-glucosamine and its derivatives

The growth inhibitory effects of D-glucosamine hydrochloride （GlcNH2-HCl）, D-glucosamine （GlcNH2） and N-acetyl glucosamine （NAG） on human hepatoma SMMC-7721 cells in vitro were investigated. The results showed that GlcNH2.HCl and GlcNH2 resulted in a concentration-dependent reduction in hepatoma cell growth as measured by MTT （3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide） assay. This effect was accompanied by a marked increase in the proportion of S cells as analyzed by flow cytometry. In addition, human hepatoma SMMC-7721 cells treated with GlcNH2-HCl resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis. NAG could not inhibit the proliferation of SMMC-7721 cells. GlcNH2-HCl exhibited antitumor activity against Sarcoma 180 in Kunming mice at dosage of 125-500 mg/kg, dose of 250 mg/kg being the best. GlcNH2-HCl at dose of 250 mg/kg could enhance significantly the thymus index, and spleen index and could promote T lymphocyte proliferation induced by ConA. The antitumor effect of GlcNH2-HCl is probably host-mediated and cytocidal.

Preparation of Sn-β-zeolite via immobilization of Sn/choline chloride complex for glucose-fructose isomerization reaction

Well dispersion of tin species in an isolated form is a quite challenge since tin salts are easily hydrolyzed into（hydr）oxides during aqueous stannation of β-zeolite.In this study,immobilization of tin species on high silica commercial β-zeolite by using SnCl_2/Choline chloride（ChCl） complex followed with calcination provided a convenient way to get well dispersed Sn in β-zeolite in the aqueous condition,which was observed based on electron microscopy images,UV visible spectra and X-ray diffraction pattern.The existence of ChCl facilitated tin species to incorporate into zeolite.（1-2）wt%of Sn loaded β-zeolites exhibited good catalytic activity and high selectivity for glucose-fructose isomerization reaction.

A clean process of lead recovery from spent lead paste based on hydrothermal reduction

An innovative process was proposed for recovering lead from spent lead paste, and it produced less pollution and used lessenergy than the traditional process. First, lead dioxide in lead paste was reduced by glucose under hydrothermal conditions. Theeffects of the reaction time, glucose excess coefficient, temperature and pH on the hydrothermal reduction were systematicallyinvestigated. Under the optimized reduction conditions （i.e., temperature of 175 ℃, time of 120 min, glucose excess coefficient of3.0 and pH of 5.5）, 99.9% reduction ratio of lead dioxide is achieved, and only the PbO·PbSO4 and PbSO4 phases are observed in thereducing residue. Subsequently, the reducing residue is desulfurized in a NaOH solution, and approximately 99.40% of the sulfur isremoved. The main lead phase in the desulfurization residue is 3PbO·H2O.

Genetic improvement of Trichoderma ability to induce systemic resistance

The beneficial applications of Trichoderma spp. in agriculture include not only the control of plant pathogens, but also the improvement of plant growth, micronutrient availability, and plant tolerance to abiotic stress. In addition, it has been suggested that these fungi are able to increase plant disease resistance by activating induced systemic resistance (ISR) . The mode of action of these beneficial fungi in the Trichoderma -plant-pathogen interaction are many, complex and not completely understood. Numerous lytic enzymes have been characterized, the encoding genes (ech42 gluc78, nag1 from T. atroviride strain P1) cloned, and their role in biocontrol demonstrated. The corresponding biocontrol-related inducible promoters have been used in a reporter system based on the Aspergillus niger glucose oxidase gene (goxA) to monitor biocontrol activity. Glucose oxidase catalyzes the oxygen-dependent oxidation of D-glucose to D-glucono-1,5-lactone and hydrogen peroxide; this latter compound is known to have an antifungal effect and activate the plant defence cascade, thus increasing resistance to pathogen attack. T. atroviride P1 transformants with various promoters gox were tested as seed coating treatments on bean seeds planted in soil infested with a soilborne fungal pathogen. Successively, the emergent leaves were inoculated with a foliar pathogen to determine the effect of the GOX transformants on biocontrol and resistance to pathogen attack. Inoculations with the P1-GOX transformants not only reduced disease symptoms caused by a soil pathogen, but also the lesions of various foliar pathogens applied far from the Trichoderma colonization, thus activating ISR. A similar approach is being use to genetically improve T. harzianum T22, a rhizosphere competent and commercially marketed strain not transformed yet, by using four different gox gene constructs under the control of constitutive and inducible promoters. Plasmids have been introduced in Trichoderma by protoplasts co-transformation. hygromicin resistant progeny selected, and mitotically stable transformants analysed to confirm the presence of the novel enzyme activity. Progenies are being tested for biocontrol ISR inducing activity.

Glucose Isomerization into Fructose Catalyzed by MgO/NaY Catalyst

The MgO/NaY catalysts prepared by impregnation method were used for the conversion of glucose to fructose in water medium. The effects of MgO loading, reaction temperature, glucose concentration and reaction time on the catalytic performance for the reaction were studied. The activity testing results indicated that fructose could be generated effectively by controlling the components of the catalyst and reaction conditions. The maximal fructose yield of 33.8% with the selectivity of 67.3% was achieved over the 10%MgO/NaY catalyst at 100 ℃ for 2 h. Moreover, the catalysts were characterized by XRD, BET, and CO2-TPD techniques. The structural property of NaY with higher surface area facilitated glucose conversion, and the modulated basicity of the catalyst with MgO addition contributed to the formation of fructose in the tautornerization of aldose to ketose.

Conversion of Glucose to Valuable Platform Chemicals over Graphene Solid Acid Catalyst

Biomass-derived hexose sugars, the most abundant renewable resources in the world, have potential to be the sustainable resources for production of platform chemicals. Here, con- version of glucose is investigated by using sulfonated graphene （rGO-SOaH） as solid acid catalyst in water without any organic solvent. At first, graphene functionalized with sulfonic acid groups is prepared by using Nail and propane sultone, and then it is characterized by means of XPS, FT-IR, and TEM to confirm the existence of the sulfonic acid groups. The catalytic activity of rGO-SOaH in the conversion of glucose to valuable chemicals is studied under different reaction conditions. The maximum yield of 5-hydroxymethylfurfural （HMF） is 28.8%, and the total yield of formic acid, lactic acid and HMF is 51.94% when the reaction is conducted at the optimized reaction condition. In addition, the rGO-SOaH gives a rela- tively high total yield of the three kinds of products after five run experiments, indicating that the catalyst shows good thermal stability.

Structural sensitivity of heterogeneous catalysts for sustainable chemical synthesis of gluconic acid from glucose

Gluconic acid and its derivatives have been widely used in the food and pharmaceutical industries. Conventional processes that involve the conversion of glucose into gluconic acid via fermentation present several technological shortcomings as they involve energy-intensive wastewater treatment and complex enzyme separation. Greener oxidation processes over heterogeneous metal catalysts have attracted increasing attention worldwide. Au-, Pt-and Pd-based heterogeneous catalysts have been extensively used for the chemical oxidation of glucose to gluconic acid. Bimetallic catalysts synthesized by adding either noble or inexpensive metals have also presented excellent performance for the oxidations of glucose. In particular, particle size, which has been recognized as the most important factor that affect catalytic performances, could be rationally tuned by changing the types of support and ligand as well as the synthesis conditions. In this perspective review, we summarize and critically discuss the recent advances in the structural design of mono-and bimetallic catalysts for the oxidation of glucose in aqueous media. Furthermore, the challenges of developing catalysts for the green synthesis of gluconic acid have been highlighted. This review provides alternative insights for designing effective catalytic materials for the catalytic oxidation of bio-derived oxygenates over heterogeneous catalysts.

Comparative analysis of hydrogen-producing bacteria and its immobilized cells for characteristics of hydrogen production

A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively. In continuous cultures at medium retention time of 2.0 h, the yield and the evolution rate of hydrogen production by the immobilized cells were 2.31 mol/mol glucose and 1 435.4 ml/（L·h） respectively. However, at medium retention time of 6.0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9 ml/（L·h）, respectively.

Polyaniline-graphite composite film glucose oxidase electrode

A novel polyaniline-graphite composite film glucose oxidase （PGCF GOD） electrode was developed. The PGCF was synthesized by cyclic voitammetry method in 0.5 mol/L H2SO4 solution containing 1 g/L graphite powder and 0.2 mol/L aniline. The PGCF GOD electrode was prepared by doping GOD into the composite film. The morphology of the PGCF and the response property of the PGCF GOD electrode were investigated by scanning electron microscopy and electrochemical measurement, respectively. The results show that the PGCF has a porous and netty structure and the PGCF GOD electrode has excellent response property such as high sensitivity and short response time. Influences of pH value, temperature, glucose concentration and potential on the response current of the electrode were also discussed. The sensor has a maximum steady-state current density of 357.17μA/cm2 and an apparent Michaelis-Menten constant of 16.57 mmol/L. The maximum current response of the enzyme electrode occurs under the condition ofpH 5.5, 0.8 V and 65℃.