Synthesis and structure of O-(arylcarbamoyl)butyrhydroximoyl chlorides

The O-(arylcarbamoyl)butyrhydroximoyl chlorides were synthesized, and the x-ray structural analysis (XSA) of one of them — O-(o-tolylcarbamoyl)butyrhydroximoyl chloride — was performed. It was established from the data of the XSA and the PMR spectra that all synthesized compounds are the Z isomers.Institute of Physiologically Active Substances, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 315–319, February, 1992.     

Studies on O-,N-Acylation of 3-Hydroxyisoxazole and Their Regioselective Synthesis(Ⅰ)——O-,N-acylation of 5-Methyl-3-hydroxyisoxazole with 2,2-Dimethyl 3-Substituted Cyclopropanecarboxylic Chlorides

The reactions of 5-methyl-3-hydroxyisoxazole with 2, 2-dimethyl, 3-substituted cyclopropanecarboxylic chlorides give O-acyl-5-methyl-3-hydroxyisoxazole and N-acyl-5-methylisoxazolin-3-one derivatives. The ratio of O-acyl to N-acyl product depends upon the acylation reagents. O-acyl derivatives can be converted to the N-acyl compounds by isomerization under acidic conditions or heating.     

Ba(Zr0.3Ti0.7)O3 铁电薄膜的制备

介绍了用溶胶-凝胶法(sol-gel)在Pt/Ti/SiO2/Si衬底和石英衬底上制备Ba(Zr0.3Ti0.7)O3铁电薄膜的基本原理、工艺过程及工艺特点;Sol-gel制备的Ba(Zr0.3Ti0.7)O3铁电薄膜表面平整、厚度均匀.     

Selective Oxidation of Methane to Methanol Using Molecular Oxygen on MoOx／（LaCoO3＋Co3O4） Catalysts

Comparatively high CH3OH selectivity (60.0%) and yield (6.7%) were obtained on MoOx/(LaCoO3 Co3O4) catalysts in selective oxidation of methane to methanol using molecular oxygen as oxidant. The interaction between MoOx and La-Co-oxide modified the molecular structure of molybdenum oxide and the ratio of O^-/O^2- on the catalyst surface, which controlled the catalytic performance of MoOx/(LaCoO3 Co3O4) catalysts.     

Sulfur Ligands. from β-Lactam Antibiotics to Contrast Agents for MRI

Abstract

NMR, IR and semi empirical Molecular Orbital PM3 studies on selected β-lactam antibiotics are reported. The role of sulfur in β-lactam antibiotics is discussed.     

Open tubular capillary electrochromatography: A useful microreactor for collagen I glycation and interaction studies with low-density lipoprotein particles

Diabetes, a multifunctional disease and a major cause of morbidity and mortality in the industrialized countries, strongly associates with the development and progression of atherosclerosis. One of the consequences of high level of glucose in the blood circulation is glycation of long-lived proteins, such as collagen I, the most abundant component of the extracellular matrix (ECM) in the arterial wall. Glycation is a long-lasting process that involves the reaction between a carbonyl group of the sugar and an amino group of the protein, usually a lysine residue. This reaction generates an Amadori product that may evolve in advanced glycation end products (AGEs). AGEs, as reactive molecules, can provoke cross-linking of collagen I fibrils. Since binding of low-density lipoproteins (LDLs) to the ECM of the inner layer of the arterial wall, the intima, has been implicated to be involved in the onset of the development of an atherosclerotic plaque, collagen modifications, which can affect the affinity of native and oxidized LDL for collagen I, can promote the entrapment of LDLs in the intima and accelerate the progression of atherosclerosis.In this study, open tubular capillary electrochromatography is proposed as a new microreactor to study in situ glycation of collagen I. The kinetics of glycation was first investigated in a fused silica collagen I-coated capillary. Dimethyl sulphoxide, injected as an electroosmotic flow marker, gave information about the charge of coating. Native and oxidized LDL, and selected peptide fragments from apolipoprotein B-100, the protein covering LDL particles, were injected as marker compounds to clarify the interactions between LDLs and the glycated collagen I coating. The method proposed is simple and inexpensive, since only small amounts of collagen and LDL are required. Atomic force microscopy images complemented our studies, highlighting the difference between unmodified and glycated collagen I surfaces.     

γ辐照掺杂SiO2的ESR研究

分别掺有磷和硼的二氧化硅经γ辐照后产生多种顺磁性中心,ESR研究指出氧空穴O^-主要稳定在杂质离子附近.O₂^-自由基稳定在Si离子上.F心的研究认为氧缺位俘获电子存在一个动态平衡过程.     

正电子发射显像剂O-(2-[18F]氟乙基)-L-酪氨酸的新型前体的合成

设计合成了5种新型正电子发射断层显像剂[O-(2-[¹⁸F]氟乙基)-L-酪氨酸的前体化合物：N-叔丁氧羰基-O-(2-甲磺酰/对硝基苯磺酰)-氧乙基-L-酪氨酸甲酯(9a,11a)和N-叔丁氧羰基-O-(2-甲磺酰/对甲苯磺酰/对硝基苯磺酰)-氧乙基-L-酪氨酸叔丁酯(9b,10b,11b)。 这些化合物以L-酪氨酸为原料,先与甲醇发生酯化反应或与乙酸叔丁酯进行酯交换,再用叔丁氧羰基保护氨基,最后以碳酸钾为碱、18-冠-6为相转移催化剂与乙二醇的磺酸酯在丙酮溶液中加热回流形成目标化合物,总收率为30%～67%。     

N,N-二(邻硝基苯氨基乙基)甘氨酸糖酯的合成

在筛选抗植物病毒剂的研究中发现N,N-二(邻硝基苯氨基乙基)甘氨酸具有较好的抑制烟草花叶病毒(TMV)的活性,为提高其抗病毒活性,根据一些糖酯具有生理活性,而且它们的活性和药理性质都比同系物非糖酯要好,因此决定合成标题酸的酯基葡萄糖、乳糖、半乳糖和木糖酯,这些酯均为新化合物。