STUDIES ON THE CRYSTAL STRUCTURE OF Al-(D-TRYPTOPHAN) INSULIN

We have determined the crystal structure of Al-(D-Trp) insulin and discovered that it belongs to the trigonal system with space group R3. The parameters of the unit cell are a=b=78.6, c=50.0. A set of data for half a sphere reciprocal space to a spacing of 2.2 were collected. The model was adjusted and refined by using a step-by-step approach and a stereochemically-restrained least squares program, assisted by manual revision based on the difference Fourier maps, to a final R-factor of 0.218. The main and side chains of both Al-D-Trp residues in the asymmetric unit are well ordered. The packing of Al-(D-Trp) insulin in the unit cell, the conformational differences with other insulin structures and its structure and function relationship bave also been discussed.     

CATIONIC CONDUCTIVITY FOR THE CROSSLINKED P [OLIGO (OXYETHYLENE) METHACRYLATE-COoMETHACRYLOYL ALKYLSULFONIC ACID LITHIUM]

Crosslinked copolymers with single Li~+-ionic conductivity were prepared from oligo (oxyethylene) methacrylate (MEO_n), methacryloyl alkylsulfonic acid lithium (SAMLi), and oligo (oxyethylene) dimethacrylate (DMEO_n). Li~+-ionic conductivity of the copolymer is improved by crosslinking and presented as a function of polymerization degree (n) in MEO_n, comonomeric salt concentration (O/Li), and crosslinking degree. The crosslinked copolymer P (0.7 MEO_(14)-0.3DMEO_(14)-SHMLi) without other small molecular additives exhibits an optimum Li~+-ionic conductivity of 1.2×10~(-6) S/cm at 25℃. Dc polarization test in the cell composed of Li/copolymer/Li shows a constant dc ionic conductivity which closes gradually to the ac one with decreasing dc polarization potential.     

新型含二茂铁有机配合物的合成及其电化学性质

以二茂铁为起始原料,经氯汞化反应、溴代反应、Suzuki偶联反应、水解反应和取代反应等5步反应合成了一种新型的含二茂铁结构单元的有机配合物(7),其结构经1H NMR、13C NMR、IR和HR-MS(ESI-TOF)表征。电化学研究结果表明:化合物6的E1/2小于化合物7,具有较高的氧化还原活性。     

Doublet Chirality Transfer and Reversible Helical Transition in Poly(3,5‐disubstituted phenylacetylene)s with Pyrene as a Probe Unit†

A novel doublet chirality transfer (DCT) model was demonstrated in cis poly(3,5‐disubstituted phenylacetylene)s, i.e., S‐I , R‐I , and S‐I‐NMe . The chiral message from the stereocenter of alkylamide substituent at 3‐position induced the polyene backbone to take cis‐transoid helical conformation with a predominant screw sense. And in turn the helical backbone acted as a scaffold to orient the pyrene probes, which was linked to phenyl rings through 5‐position, to array in an asymmetric manner. A combinatory analyses of ¹H NMR, Raman, FTIR, UV‐vis absorption, CD, and computer simulation suggested that the main‐chain stereostructure, solvent nature, and intramolecular hydrogen bonds played important and complex roles on DCT. High cis‐structure content and intramolecular hydrogen bonds were beneficial for the realization of DCT. Reversible helix‐helix transition was observed in S‐I by changing the nature of solvents. In DMF, S‐I adopted a relatively contracted helix, where the main chain exhibited strong optical activity, but that of pyrene was weak. In contrast, a relatively stretched helix formed in CHCl₃, in which the optical activity of pyrene was much larger, whereas that of the polyene backbone was the weakest. This helix‐helix transition was attributed to the intramolecular hydrogen bonds, which was confirmed by solution‐state FTIR spectra and computer calculations.     

α-(2-苯并噻唑氧基)烃基膦酸酯的合成性质和生物活性

为探索α-芳(杂 环)磷酸衍生物的生物活性,寻求含磷农药的新母体,合成了十六个未见文献报道的α-(苯并噻唑-2-氧代)烃基膦酸衍生物,所有化合物的结构均IR,HNMR, 元素分析等确证,并对生物活性进行了初步的研究.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER

Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl toquinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M_w ca. 750) as flexible segments, were synhesized. Thechemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by ~1H-NMR and MALDI-TOF mass spectromeny. The diblock oligomers showed good solubility in common organic solvents and aggregated in wateras characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescenceand formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant thatthis effort might lead to commercial important highly organized functional materials.     

A New Anthraquinone from Clinopodium polycephalum Glyceroyl-1,6,8-trihydroxy-3-methyl-9,10-dioxo-2-anthracene Carboxylate

ClnOPodiumpoIycePhalum(VantjCYWhetHsuancalled'DuanXielin'inChineseisusedinfolkmedicineforthetreatInentofhaemorrhagiadisease.lInordertofmdtheactivecomPounds,studiesonthechedricalconstituentsofthewholeplan,collectedatHuoShanofAnhuiprovince,werecarriedout.Fromthealcoholicextracts,wehaveisolatedanewanthraquinone,Glyceroyl-l,6,8-trihydroxy-3-methyl-9)lO-dioxo-2-anthrcenecarboxylateI(Figurel).Iwasobtainedasredneedles,mP:ll9-l2l"C.TheHR-MSdareaffordedthefor-mulaasCl9Hl6O9(Found388.O791;…     

液晶性芳香酰胺化合物的合成

合成了一系列炖粹以酰胺基为中心桥键的刚性芳香酰胺小分子化合物，并对其作了表征，发现其中有些化合物具有液晶性。酰胺键之间能形成很强的分子间氢键，使芳香酰胺小分子化合物的熔点很高，难于形成液成液晶态。研究发现，如果在这类化合物的中心苯环上引入合适的取代基以减弱分子间氢键，同时引入合适的末端基时，则可使芳香酰胺化合物生成液晶相的能力增强。     

STUDIES ON ENHANCED CONDUCTIVITY OF STRETCHED CONDUCTING POLYMERS

A physical model of series of the conductivity on chain and the interchain conductivitybetween chains is proposed to explain enhanced conductivity of stretched conducting polymers.This model suggests that the enhanced conductivity for stretched conducting polymers might bedue to increasing of the interchain conductivity between chains along the elongation direction afterdrawing processes if the conductivity on chain is assumed much larger than that of the interchainconductivity between chains. According to this model, it is expected that the temperaturedependence of conductivity measured by four-probe method for stretched conducting polymers iscontrolled by a variation of the interchain conductivity between chains with temperature, whichcan be used to explain that a metallic temperature dependence of conductivity for stretchedconducting polymers is not observed although the conductivity along the elongation direction isenhanced by two or three orders of magnitude.     

Electrochemical study of bergenin on a poly(4-(2-pyridylazo)-resorcinol) modified glassy carbon electrode and its determination in tablets and urine

A very sensitive electroanalytical method was employed to determine bergenin in phosphate buffer with a pH of 6.0, bergenin was accumulated at a 4-(2-pyridylazo)-resorcinol (PAR) polymer film modified glassy carbon electrode (GCE) surface under the condition of open-circuit. In the following anodic sweep from −0.4 to 0.8 V, bergenin adsorbed at the PAR polymer film modified electrode surface, was oxidized and yielded a sensitive oxidation peak at 0.595 V. Due to its unique structure and extraordinary properties, the PAR polymer film shows higher accumulation efficiency toward bergenin compared with a bare GCE. Hence, the amount of bergenin at the PAR polymer film modified GCE surface increases significantly, and finally the oxidation peak current improves greatly. The experimental conditions, such as supporting electrolyte, pH value, accumulation time and scan rate, were optimized for the measurement of bergenin, and a sensitive electroanalytical method was proposed for bergenin determination. The oxidation peak current varies linearly with the concentration of bergenin over the range of 2.0 × 10⁻⁷ to 1.2 × 10⁻⁵ mol/L, and the detection limit is 2.0 × 10⁻⁸ mol/L after 3 min open-circuit accumulation. The relative standard deviation of the same electrode in 10 successive scans is 1.8% for 1.0 × 10⁻⁶ mol/L bergenin and 2.1% for interelectrodes, indicating excellent reproducibility. This new method was successfully demonstrated with bergenin tablets and diluted urine.