First synthesis of a malarial prototype: a fully lipidated and phosphorylated GPI membrane anchor

A strategy is described for syntheses of a fully lipidated and phosphorylated prototype of the GPI of Plasmodium falciparum, the causative agent of lethal cerebral, drug-resistant malaria. Orthoesters, prepared in four steps from d-mannose, and methyl α-d-glucopyranoside are the key starting materials. The latter furnishes the inositol moiety using Bender’s procedure, while the former gives the other four units of the pseudo-pentasaccharide. The strategy for installing the three biologically important acyl units of the phosphoinositide has been worked out. The critical, biosynthetically important C2-O-acyl group of the inositol is exceptionally stable, showing no tendency to migrate to the cis-related C3-OH in several test substrates.     

S-甘油醛缩丙酮的合成及其Wittig反应

以L-抗坏血酸为原料合成了S-甘油醛缩丙酮;研究了S-甘油醛缩丙酮的Wittig反应立体选择性.     

Effects of dipole moment, linkers, and chromophores at side chains on long-range electron transfer through helical peptides

Octadecapeptides carrying a ferrocene moiety at the molecular terminal were self-assembled on gold, and long-range electron transfer from the ferrocene moiety to gold was investigated by electrochemical methods. Effects on electron transfer of dipole moment of helical peptides, linkers connecting the peptide to gold, and chromophores introduced into the side chains were discussed. Cyclic voltammetry of the monolayers in an aqueous solution revealed that long-range electron transfer over 40 A occurred along the peptide molecule. Chronoamperometry showed that the long-range electron transfer should be ascribed to a hopping mechanism with use of amide groups as hopping sites. Electron transfer through the long peptide was not significantly accelerated by the dipole moment. However, the linker remarkably affected electron transfer depending on whether it was a methylene chain or a phenylene group, suggesting that local electron transfer between gold and the peptides should be the slowest step to determine the overall rate. Pyrenyl groups introduced into the side chains in the middle of the peptide molecule did not noticeably change electron transfer, probably because pyrenyl groups were too distant to allow direct electron transfer between them. Electrostatic potential profiles across the peptide monolayers were also calculated to explain reasonably the several interesting features in the present peptide systems.     

Template-synthesized LiCoO2, LiMn2O4, and LiNi0.8 Co0.2 O2 nanotubes as the cathode materials of lithium ion batteries

The first point of this work is to synthesize LiCoO2, LiNi0.8 Co0.2 O2, and LiMn2O4 nanotubes with the template of porous anodic aluminum oxide by thermal decomposition of sol-gel precursors. The as-synthesized materials were open-ended nanotubes with uniform shape and size based on the analysis of scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. An "in situ reaction from nanoparticle to nanotube" mechanism was discussed for the formation process of the nanotubes. The second point of this paper is to investigate the electrochemical properties of the as-synthesized nanotubes for the cathode materials of lithium ion batteries. It was found that the nanotube electrodes exhibited better reversibility and higher discharge capacities than that of their nanocrystalline counterparts. The reason for the improved electrochemical performance of the nanotube electrodes was also interpreted.     

多氟烷基取代的环丙烷衍生物的合成

以连二亚硫酸钠为引发剂, 烯丙基丙二酸二乙酯与多氟烷基碘代烷在温和反应条件下反应, 方便地得到一系列多氟烷基取代的环丙烷衍生物, 产率45%～55%. 在相同条件下, 烯丙基乙酰乙酸乙酯与多氟烷基碘代烷反应得到相应的加成物, 加成物随后用碱处理也得到环合的产物.     

The Purification of Glucose Type Glycosyl Nitrate and the Synthesis of Spacer—armed N—Acetyllactosamines and Their Dimers

Our previous paper1,2reported the results of selective synthesis of mannose type glycosides and their dimers in our attempt to synthesize derivatives of N-acetyllacto- samine, which could have potential activity of anti-metastasis3. Further studies on the glycosylation of the accepters exploiting glycosyl nitrate instead of the acetate as donor showed interesting chemoselectivity between the two kinds of donor, namely, the glucose type and the mannose type. The reactivity difference of the t…     

PP/LDPE共混体系的辐射效应

研究了在多官能团单体—三烯丙基异氰脲酸酯存在下ＰＰ／ＬＤＰＥ共混体系接受γ－辐射的效果。用溶解度参数和ＴＥＭ技术评估了共混体系的相容性与多官能团单体在共混体系中的分布，并用ＳＥＭ、ＤＳＣ、动态力学等方法对共混体系相容性进行了表征。结果表明，ＰＰ／ＬＤＰＥ是不相容的共混体系，三烯丙基异氰脲酸酯主要分布在共混体系的相界面区域，辐照强化了共混体系的相间结合，增加了界面厚度，改善了共混体系的相容性。     

醇脱氢酶结构和作用机理研究进展

介绍了醇脱氢酶的种类, 酵母醇脱氢酶和肝醇脱氢酶等两类常用的醇脱氢酶的物理化学性质和活性位点结构. 归纳了对肝醇脱氢酶和酵母醇脱氢酶作用机理的研究, 重点评述了醇脱氢酶催化反应中的两个关键步骤质子转移和氢化物转移过程机理的研究进展.     

Building addressable libraries: the use of electrochemistry for spatially isolating a heck reaction on a chip

Pd(0) was generated at preselected sites on an electrochemically addressable chip and then utilized to effect a Heck reaction. The Pd(0) was confined to the preselected electrodes with the use of allylmethyl carbonate. Unlike most mediated electrochemical reactions, the electrolysis in this case was not used to convert a stoichiometric process into a catalytic one by recycling the metal. Instead, the unique environment of the chip was used to interfere with a catalytic process to make it stoichiometric. This was done to gain spatial control over the reaction. The development of a strategy for conducting Pd(0)-catalyzed reactions on the chips should greatly expand the synthetic chemistry available for building chip-based libraries.