D-Psicose,a Sweet Monosaccharide,Ameliorate Hyperglycemia,and Dyslipidemia in C57BL/6J db/db Mice

ABSTRACT: D-psicose has been implicated in glycemic control in recent animal and human studies. In this study, the effects of D-psicose on glycemic responses, insulin release, and lipid profiles were compared with those of D-glucose and D-fructose in a genetic diabetes model. C57BL/6J db/db mice were orally supplemented with 200 mg/kg BW of D-psicose, D-glucose, or D-fructose, respectively, while diabetes control or wild type mice were supplemented with water instead. D-psicose sustained weight gain by about 10% compared to other groups. The initial blood glucose level maintained from 276 to 305 mg/dL during 28 d in the D-psicose group, whereas a 2-fold increase was found in other groups (P < 0.05) among diabetic mice. D-psicose significantly improved glucose tolerance and the areas under the curve (AUC) for glucose among diabetes (P < 0.05), but had no effect on serum insulin concentration. The plasma lipid profile was not changed by supplemental monosacchrides, although the ratio of LDL-cholesterol/HDL-cholesterol was ameliorated by D-psicose. The administration of D-psicose reversed hepatic concentrations of triglyceride (TG) and total cholesterol (TC) by 37.88% and 62.89%, respectively, compared to the diabetes control (P < 0.05). The current findings suggest that D-psicose shows promise as an antidiabetic and may have antidyslipidemic effects in type 2 diabetes.     

苯酚—淀粉胶的研制

本文介绍了以淀粉代替甲醛和部分苯酚制备类似于酚－醛胶的苯酚－淀粉胶，从而改善生产及施工环境，降低生产成本。     

2-脱氧-D-葡萄糖的合成

以无水葡萄糖为原料,通过乙酸酐保护、HBr溴代、锌粉还原、脱保护和酸水解5步反应合成了2-脱氧-D-葡萄糖,总收率为30%,其结构经过核磁共振谱图分析验证。该合成新方法与传统方法相比,避免了催化加氢步骤,缩短了总反应时间,提高了总产率,减少生产成本,简化工艺操作,适宜工业化规模生产。     

Quick identification of a simple enzyme deactivation model for an extended-Michaelis-Menten reaction type. Exemplification for the D-glucose oxidation with a complex enzyme deactivation kinetics

One essential engineering problem when developing an industrial enzymatic process concerns the model-based design and optimal operation of the enzymatic reactor based on the process and enzyme inactivation kinetics. For a complex enzymatic system, the “default” used first-order enzyme deactivation model has been proved to lead to inadequate process design or sub-optimal operating policies. The present study investigates if a complex enzyme deactivation can be approximated with simple 1st, 2nd, or a novel proposed model with variable deactivation constant. The approached complex enzymatic system is those of the oxidation of D-glucose to 2-keto-D-glucose in the presence of pyranose 2-oxidase. The necessary “simulated experimental data” have been generated by means of an extended kinetic model from literature used to simulate a batch reactor under well-defined nominal conditions. The proposed enzyme deactivation model has been found to be the best lumping alternative, presenting several advantages: simplicity, flexibility, and a very good adequacy.     

催化氧化葡萄糖制葡萄糖酸的动力学

以Au/C为催化剂,在间歇反应釜中考察了搅拌速率、催化剂粒径和反应温度对催化氧化葡萄糖制备葡萄糖酸的影响,并利用Aspen Plus软件中内置的LHHW动力学方程对实验数据进行拟合.结果表明,Au/C催化葡萄糖合成葡萄糖酸反应的活化能和指前因子分别为8.5× 104 J/mol和3.2× 1011 mol/(g·s)....     

Sugar-based bicyclic monomers for aliphatic polyesters: a comparative appraisal of acetalized alditols and isosorbide

Three series of polyalkanoates (adipates, suberates and sebacates) were synthesized using as monomers three sugar-based bicyclic diols derived from D-glucose (Glux-diol and isosorbide) and D-mannose (Manx-diol). Polycondensations were conducted in the melt applying similar reaction conditions for all cases. The aim was to compare the three bicyclic diols regarding their suitability to render aliphatic polyesters with enhanced thermal and mechanical properties. The ensuing polyesters had molecular weights (M_w) in the 25,000–50,000 g mol^?1 range with highest values being attained for Glux-diol. All the polyesters started to decompose above 300 °C and most of them did not display perceivable crystallinity. On the contrary, they had glass transition temperatures much higher than usually found in homologous polyesters made of alkanediols, and showed a stress–strain behavior consistent with their T_g values. Glux-diol was particularly effective in increasing the T_g and to render therefore polyesters with high elastic modulus and considerable mechanical strength.     

2-氯乙基-2，3，4，6-四-O-乙酰基-β-D-吡喃葡萄糖苷的合成

2-氯乙基-2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖苷是重要的药物合成中间体．以D-葡萄糖为原料,一锅法合成2,3,4,6-四-O-乙酰基-α-D-1-溴代吡喃葡萄糖供体．该供体在促进剂碳酸银的作用下与2-氯乙醇偶联,立体专一性地得到了1,2-反式结构的2-氯乙基-2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖苷．目标化合物的结构经氢谱分析得到了确证,方法简便,实用．     

298.15K时甘露醇-山梨醇-葡萄糖-水四元系及其二元系的密度和黏度

To check the applicabilities of the simple density equation and viscosity equation in the semi-ideal solution theory to nonelectrolyte solutions, the densities and viscosities were measured for the quaternary system mannitol-sorbitol-D-glucose-H2O and its ternary subsystems mannitol-D-glucose-H2O and sorbitol-D-glucose-H2O at 298.15K. The results were used to test the applicability of the simple equations for the density and viscosity of the multicomponent nonelectrolyte solution. The agreements between the predicted and measured results are good.     

Photophysical Properties of BADAN Revealed in the Study of GGBP Structural Transitions

The fluorescent dye BADAN (6-bromoacetyl-2-dimetylaminonaphtalene) is widely used in various fields of life sciences, however, the photophysical properties of BADAN are not fully understood. The study of the spectral properties of BADAN attached to a number of mutant forms of GGBP, as well as changes in its spectral characteristics during structural changes in proteins, allowed to shed light on the photophysical properties of BADAN. It was shown that spectral properties of BADAN are determined by at least one non-fluorescent and two fluorescent isomers with overlapping absorbing bands. It was found that BADAN fluorescence is determined by the unsolvated “PICT” (planar intramolecular charge transfer state) and solvated “TICT” (twisted intramolecular charge transfer state) excited states. While “TICT” state can be formed both as a result of the “PICT” state solvation and as a result of light absorption by the solvated ground state of the dye. BADAN fluorescence linked to GGBP/H152C apoform is quenched by Trp 183, but this effect is inhibited by glucose intercalation. New details of the changes in the spectral characteristics of BADAN during the unfolding of the protein apo and holoforms have been obtained.     

基于GGBP蛋白绑定的表面等离子共振葡萄糖浓度测量

人体糖尿病的微创检测是通过测量人体表皮组织液中的葡萄糖浓度,来预测人体血液中的葡萄糖浓度.采用表面等离子共振（SPR）技术,并使用对葡萄糖有特异性吸附的D-半乳糖/D-葡萄糖结合蛋白（GGBP）,研究组织液测试的方法.实验中针对不同的GGBP蛋白配置了不同浓度的葡萄糖溶液.将突变蛋白（E149C）,（E149C,A213S）和（E149C,A213S,L238S）分别绑定在传感器上.实验结果表明,使用不同蛋白质修饰过的表面等离子共振传感器,能够测量不同浓度范围的葡萄糖溶液,其中GGBPE149（E149C为突变位点）有最高的灵敏度,在测量葡萄糖水溶液浓度0.5mg/L～5mg/L时有较好的线性.实验结果显示了GGBP蛋白在糖尿病检测及其他人体组织成分检测领域的良好应用前景.