Effect of maltodextrins on the surface activity of small-molecule surfactants

We report on the effect of commercially important polysaccharides (maltodextrins with variable dextrose equivalent (Paselli SA-2, MD-6 and MD-10) on the surface activity at the air–water interface of small-molecule surfactants (sms), possessing different hydrophobic–lipophilic balance ((SSL (Na⁺), the main component is a sodium salt of stearol–lactoyl lactic acid, and PGE (080), polyglycerol ester of C18 fatty acid), and widely used in food products. A marked change of the surface activity of sms was found in the presence of maltodextrins by tensiometry. The combined data of laser multiangle light scattering and mixing calorimetry have suggested that this result is governed by specific complex formation between maltodextrins and sms in aqueous medium. Measurements have been made of the molar mass, the second virial coefficient and the enthalpy of intermolecular interactions in aqueous solutions. The implication of a degree of polymerization of maltodextrins in this phenomenon was shown. The interrelation between the molecular parameters of the formed complexes and their surface activity at the air–water interface has been revealed and discussed.     

Studies on the syntheses of heterocyclic compounds. CLXXIV. An approach to the synthesis of oxyacanthine and berbamine

Schotten-Baumann reaction of the amine (X) with 4-benzyloxy-3,4′-oxydiphenylacetyl chloride (XI) gave two amides, (XIIa) and (XIIb), which were cyclized to give the corresponding 3,4-dihydroisoquinolines, respectively. Methylation of the above 3,4-dihydro-isoquinolines, followed by hydrolysis, afforded the compounds having the same composition as berbamine (Ia) and oxyacanthine (Ib), whose structures are under examination.     

Indirect Determination of Sulfide by Cold Vapor Atomic Absorption Spectrometry

A method for the determination of sulfide based on its interference with the determination of Hg by cold vapor atomic absorption spectrometry is described. The decrease in mercury absorbance at 253.7nm is proportional to the concentration of sulfide over the range of 10–320ngmL^–1. The limit of detection was found to be 7ngmL^–1 and the relative standard deviation (R.S.D.) for the determination of different concentrations of sulfide was in the range of 1.8–2.2%. This method was applied to the determination of sulfide in whole human blood after gas-phase separation.     

含硫液体烃燃料水蒸气重整制氢I．Pt／Ce0．8Gd0．2O1．9催化剂的制备、表征和抗硫性能

以柠檬酸溶胶-凝胶法合成的具有萤石结构的Ce0.8Gd0.2O1.9（CGO）复合氧化物为载体，用初湿浸润法制备了负载型Pt催化剂．纯异辛烷的重整反应结果显示，600和800℃焙烧的催化剂达到了热力学平衡转化，1000℃焙烧会导致Pt的聚集和氧化物的严重烧结，因而催化剂活性较差．抗硫测试表明，800℃焙烧的催化剂抗硫性能最好，在300μg／g硫存在下，100h内异辛烷均接近完全转化；在500μg／g硫存在下催化剂仍表现出良好抗硫性能．程序升温还原和X射线分析结果显示．800℃焙烧时Pt与CGO载体间的相互作用最强，同时催化剂具有良好的热稳定性，这是催化剂具有抗硫性能并且抗硫作用持久的根本原因．反应条件下噻吩硫完全转化成H2S，硫的转化可能是通过氧化-还原机理进行的．     

An arbitrary Lagrangian–Eulerian model for studying the influences of corrosion product deposition on bimetallic corrosion

In this paper, a model is established to simulate the time-dependent deposition of corrosion product on the metal surface by considering mass transfer, electrochemical reactions and precipitation reaction. The model is also capable of tacking the movement of metal corrosion interface and the growing interface of the corrosion product deposits via arbitrary Lagrangian–Eulerian finite element method. The current model not only can be used to predict the time-dependent metal corrosion but also for investigating the influences of the deposits’ nature on metal corrosion. The numerical results of current density and corrosion rate are in good agreement with experiments. The presented model predicts that an exponential relationship exists between the maximum corrosion depth and the porosity of corrosion product deposits, and it is also predicted that the growth of the corrosion product layer is linear relative with the root of time, which is consistent with the existing theories.     

Total Synthesis of α-Elvucitabine

Total synthesis of α-elvucitabine was achieved in 26% overall yield by a concise nine-step procedure starting from L-lyxose, with trimethylsilyl trifluoromethaneoulfonate (TMSOTf)–mediated stereocontrolled α-N-glycosidation and olefination through Barton–McCombie deoxygenation being the key steps, and the stereochemistry of the product was determined by nuclear Overhauser effect spectroscopy.     

Synthesis of Isobenzofuran-1(3H)-ones with the Aid of Silica-Supported Preyssler Nanoparticles

Silica-supported Preyssler nanoparticles appear to be a new and efficient solid acid catalyst for an economical, and environmentally benign one-pot synthesis of 3-substituted phthalides.     

3-Oxodapagliflozin as a Potent and Highly Selective SGLT2 Inhibitor for the Treatment of Type 2 Diabetes

Structural modifications of 3-OH in the glucose moiety of dapagliflozin（1）, an approved potent sodium-dependent glucose transporter 2（SGLT2） inhibitor, led to 3-oxodapagliflozin（16）, a highly potent and more selective SGLT2 inhibitor[IC50（hSGLT1）/IC50（hSGLT2）=2851 for compound 16 vs. 843 for compound 1]. 3-Oxodapagliflozin（16） exhibited in vitro（IC50=1.0nmol/L against hSGLT2 for compound 16 vs. 1.3 nmol/L for compound 1） and in vivo activities comparable to those of dapagliflozin（1）. The bioactivities of 3-oxodapagliflozin （16） warrant its further evaluation as a promising SGLT2 inhibitor for the treatment of type 2 diabetes.     

The Synthesis of 5,11,17-Trihalotetracyclo [13.3.1.13,7.19,13]henicosa-1 (19),3,5,7 (20),9,11,13 (21), 15,17-nonaene-19,20,21-triols and 5,11,17-trihalo-19,20,21-trihydroxytetracyclo [13.3.1.13,7. 19,13]henicosa-1 (19),3,5,7 (20),9,11,13(21), 15,17-nonaene-8,14-dione [1]. Cyclo-derivatives of Phloroglucide Analogues

The synthesis of the title compounds ( 1 and 3 ) is described. Some of the compounds prepared were found to be active against a number of pathogenic microorganisms in vitro. Structure-activity relationship is briefly discussed.     

Erratum to: The catalytic effect of Al-KIT-5 and KIT-5-SO3H on the conversion of fructose to 5-hydroxymethylfurfural

Research on Chemical Intermediates -