羟乙基化牛膝多糖的合成及其活性研究

以环氧乙烷为羟乙基化试剂，在碱性水溶液中，对牛膝多糖进行羟乙基化，经 过丙酮沉淀、膜分离、Sephadex G-25柱层析等分离方法得到羟乙基化牛膝多糖纯 品，检测其理化性质，并通过甲基化、GC-MS分析，初步确证糖链中羟乙基主要取 代在葡萄糖6位和困糖的1位上。药理实验表明，羟乙基化牛膝多糖对荷Lewis肺癌 小鼠NK活性具有一定促进作用。     

Crystal Structures and Magnetic Studies of Naphthalene Derivatives Containing Nitronyl Nitroxides

Introduction　　Inrecentyears,greatattentionhasbeenpaidtoorganicferromagnetism ,1mainlystimulatedbythediscoveryofthefirstgenuineorganicferromagnet (p NPNN)in 1991.2 Infact,bynowtensoforganicferromagnetshavebeensynthe sizedandwellcharacterized ,3 5buttheirferromagnetictransi tiontemperaturesarestilllow .Mostofthestudiesinthisfieldareconcentratedonnitronylnitroxidederivatives.Ononehand ,variousmulti nitronylnitroxidecompoundshavebeenprepared6 withthehopetoincreasetheintermolecularspin spininte…     

Mott–Wannier excitons in the tetragonal BaTiO3 lattice

Structural and electronic properties of excitons in the tetragonal BaTiO₃ crystal is studied using a quantum chemical method developed for crystals. The obtained defect structure corresponds to the so‐called Mott–Wannier‐type exciton having a considerable distance between the hole and electronic parts of the defect. Performed crystalline lattice relaxation shows displacements of atoms in an extensive defective region of up to 12 atoms. However, the calculated magnitudes of atomic movements are not large, normally not exceeding 0.08 Å. It is also observed that the self‐trapped exciton polarizes the lattice around it. Using the so‐called ΔSCF method, the luminescence energy due to the exciton is found to be equal to 0.94 eV. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003     

A novel secondary metabolite of Chinese ted alga Laurencia karlae

A novel skeleton compound benkarlaol (1) was isolated from the red alga Laurencia karlae Zhang et Xia, collected from the Nansha Islands in the South China Sea. Its structure and relative stereochemistry were determined by spectroscopic data, especially extensive 1D and 2D NMR experiments.     

Synthesis and X‐Ray Single Crystal Structure of Two New Copper Complexes with the Redox Active Ligand 1,10‐Phenanthroline‐5,6‐dione

The synthesis and the crystal structures of the complexes [Cu(L^I)₂](ClO₄) ( 1 ) and [Cu(L^I)(CH₃CN)₂(ClO₄)₂] ( 2 ) are reported. 1 crystallizes in the monoclinic space group C2/c with the unit cell dimensions a = 13.169(4), b = 12.289(3), c = 14.732(3) Å, β = 109.03(2)° and Z = 4. Copper(I) is coordinated to four N atoms of the two 1,10‐Phenanthroline‐5,6‐dione (L^I) ligands with a two‐fold axis passing between the ligands. The copper(II) compound 2 crystallizes in the orthorhombic space group Pbn2₁ with unit cell dimensions of a = 7.498(5), b = 23.492(7), c = 12.363(4) Å and Z = 4. Copper(II) coordination can be described as a distorted octahedron with the N donor atoms of one L^I ligand and of two molecules of CH₃CN occupying the equatorial positions completed by two oxygen atoms of the two perchlorate molecules in the axial positions.     

Synthesis and X-ray structural study of 1-adamantylmethyl 2-cyanoacrylate and 1,10-decanediol bis-2-cyanoacrylate

I-Adamantylmethyl 2-cyanoacrylate (1) was prepared by the reaction of 2-cyanoacryloyl chloride with 1-adamantylmethanol . 1,10-Decanediol bis-2-cyanoacrylate (2) was synthesized by transesterification of methyl 2-cyanoacrylate with 1,10-decanediol. Esters1 and2 were studied by X-ray structural analysis.Deceased in 1995.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2288–2292, September, 1996.     

ELECTRONIC CONFIGURATIONS OF TRANSITION METAL SANDWICH COMPLEXES

In this paper the electronic configurations of n+1-decker transition metal sandwich com-plexes have been generally discussed by means of the structural rule of transition metalheterocarborans and the numbers of their valence bonding orbitals have been obtained as fol-lows: VBO = 6n + 3-6n + 5,which are not dependent on the properties of transition metal atoms and coordination rings.Then the results of EHMO quantum chemistry calculations of the model skeletons and cor-responding analyses on electronic configurations of actual molecules for double-, triple- andtetra-decker sandwich complexes have been discussed to verify the above formula.     

Thermodynamics and structure of the ordered amorphous phase in polymers

Experimental data are analysed to show that the activation enthalpy and the structural entropy appear to follow empirical relations for structural relaxation of polymeric systems. The relations indicate that melting temperature, glass transition temperature, relaxation time, coefficient of thermal expansion of free volume are interrelated in polymers. The parameters of structural relaxations, measured by mechanical and dielectric spectroscopies, are reviewed for polyethylene, poly(4-methyl-1-pentene) and a liquid-crystalline polynorbornene derivative. The thermodynamic parameters obtained from calorimetric measurements, are reported for zero heating rate extrapolation and they are used in the empirical relation, which combines the Arrhenius and the Vogel-Fulcher formulae.     

Synthesis and crystal structure of the deuterated organic conductor, (d8-ET)4[Hg2(SCN)4Cl2]

On the basis of completely deuterated bis(ethylenedithio)tetrathiafulvalene (d₈-ET), new organic conductors, (d₈-ET)₄[Hg₂(SCN)₄Cl₂] and (d₈-ET)₂[Hg(SCN)₂Br] have been synthesized and studied by X-ray structural analysis. Unlike nondeuterated organic metalsk-(ET)₂[Hg(SCN)_3–n X _n ] (X = Cl or Br;n=1 and 2), the crystal structure of (d₈-ET)₄[Hg₂(SCN)₄Cl₄] exhibits -type packing of the d₈-ET radical cations in the conducting layer and a polymeric structure of anions, in which both the SCN groups and the Cl atoms are involved in the bridging bonds. The crystals of (d₈-ET)₂[Hg(SCN)₂Br] and the nondeuterated form (ET)₂[Hg(SCN)₂Br] are isostructural.Translated fromIzvestiya Akademii Nauk. Seriya Khlmicheskaya, No. 5, pp. 905–909, May, 1995.This work was financially supported by the International Science Foundation (Grant RE1 000), the Scientific Council on the Problems of High-Temperature Superconductivity (Project No. 93030), and the Russian Foundation for Basic Research (Project No. 94-03-09950).