Synthesis of α-S-galactosylceramides with a truncated sphingoid chain

We present here a convenient synthesis of the truncated sphingoid iodide 15 from d-galactose, in which Mitsunobu reaction was utilized to retrieve successfully an unwanted intermediate, thereby increasing greatly the synthetic efficiency. Subsequent reaction of 15 with the pre-prepared α-galactosyl thiol 16 led smoothly to the desired thioglycoside 17 in good yield, from which the catabolically stable thioglycoside analogs of OCH 4 and 22 were synthesized.     

Benzylic-acetoxylation of alkylbenzenes with PhI(OAc)2 in the presence of catalytic amounts of TsNH2 and I2

Treatment of alkylbenzenes with (diacetoxyiodo)benzene in the presence of catalytic amounts of p-toluenesulfonamide or p-nitrobenzenesulfonamide, and molecular iodine in 1,2-dichloroethane at 60 °C gave the corresponding (α-acetoxy)alkylbenzenes in good to moderate yields. The present reaction is a simple method for the introduction of an acetoxy group to the benzylic position of alkylbenzenes.     

Tandem oxidation/bromination of ethyl aromatics to α,α-dibromoacetophenones with molecular oxygen under visible light irradiation

The facile synthesis of α,α-dibromoacetophenones from ethyl-substituted aromatics by aerobic photooxidation has been developed. This synthetic method achieves oxidative dibromination of aromatic ethyl groups by using inexpensive and easily handled bromine sources, harmless visible light and molecular oxygen.     

From four to five and six coordinated sparteine and α-isosparteine mononuclear Cu(II) complexes through the carboxylate donors

Cu[(C₁₅H₂₆N₂)(OCOR)₂] complexes, where OCO is a fragment of either formato or acetato group and C₁₅H₂₆N₂ is sparteine or α-isosparteine have been synthesized and structurally characterized. The bis-formato complexes (1 and 2) display a distorted 4 + 1 coordination resulting from variable metal binding stereochemistry and function of the two formato units. The syn formato group acts as a pseudochelating bidentate while the anti conformer as a monodentate ligand. This inequivalence of the two formate ligands seems deliberate for it allows formation of the stabilizing intramolecular hydrogen bond between the CH donor belonging to the monodentate formate ligand and equatorially coordinated oxygen atom belonging to the pseudo-chelating formate ligand. At variance, the C₂ symmetrical bis-acetato complex (3) displays tetragonally elongated octahedral geometry of the CuN₂O₂O′O′ with long off-axis coordination of the second O atom from each acetate ligand in the axial position.Complexes 1-3 have been also characterized by elemental analysis, IR, UV-Vis and MS spectroscopy.     

片状微形貌聚吡咯的合成及影响因素研究

以α-环糊精和酸性红G包合物为掺杂剂,三氯化铁为氧化剂,采用无模板自组装法合成了一种新颖的片状微结构聚吡咯.用场发射扫描电镜(FESEM)、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)和X射线荧光光谱仪(XRF)对合成的片状聚吡咯的结构形貌进行了表征.结果表明,静置聚合条件下,以α-环糊精和酸性红G包合物为...     

蛋白质二硫键异构酶与α-突触核蛋白的相互作用及对其聚集的影响

α-突触核蛋白（α-synuclein,αsyn）的错误折叠和聚集是帕金森症的疾病特征.分子伴侣蛋白质二硫键异构酶（PDI）可在体外结合αsyn的N端并抑制其聚集,但PDI的识别机制至今仍不明确.我们通过液体核磁共振（NMR）实验,发现人源PDI b'xa'可结合αsyn的N端区域.此外,硫黄素T（ThT）荧光实验结果表明PDI b'xa'会显著抑制αsyn的聚集.我们进一步利用NMR滴定实验确定了PDI主要通过b'结构域的疏水空腔结合αsyn.最后,我们以此构建了PDI结合αsyn的对接模型,并提出了PDI抑制αsyn聚集的作用机理.这一工作为理解PDI抑制αsyn聚集提供了实验依据.     

Measurement of(n,α)and(n,2n)reaction cross sections at a neutron energy of 14.92±0.02 MeV for potassium and copper with uncertainty propagation

Experimentally measured neutron activation cross sections are presented for the ⁶⁵Cu(n,0)^62mCu,⁴¹ K(n,a)^38Cl,and ⁶⁵Cu(n.2n)⁶⁴Cu reactions with detailed uncertainty propagation.The neutron cross secions were measured at an incident energy of 14.92±0.02 MeV,and the neutrons were based on the(d,n)a fusion reaction.The ²⁷ Al(n,a)²⁴Na reaction was used as a reference reaction for the normalization of the neutron flux.The pre-calib-rated lead-shielded HPGe detector was used to detect the residues'γ-ray spetra.The data from the measured cross sections are compared to the previously measured cross sections from the EXFOR database,theoretically calculated cross sections using the TALYS and EMPIRE codes,and evaluated nuclear data.     

基于纳米银与有机多孔材料/纳米金修饰的甲胎蛋白免疫传感器研究

在金电极表面电沉积银为氧化还原探针,利用有机多孔材料(PTC-NH2)、纳米金(nano-Au)固载甲胎蛋白抗体(anti-AFP),制备出用于检测甲胎蛋白(AFP)的安培型免疫传感器。通过交流阻抗技术、循环伏安法研究了电极的电化学特性,考察了孵育时间、测试液pH值等实验条件对传感器性能的影响,并利用扫描电子显微镜(SEM)对电极的修饰过程进行了表征。该传感器对AFP有良好的电流响应,线性范围分别为1.0～20.0ng/mL和20.0～60.0 ng/mL,检测限为0.6 ng/mL。     

Catalytic conjugate addition of indole toα,β-unsaturated ketones by Co（ClO4）-2·6H2O/bis-Schiff base complexes

Co（ClO₄）)₂·6H₂O/bis-Schiff base complexes promoted the conjugate addition of indole toα,β-unsaturated ketones under mild conditions,giving the corresponding addition products with high yields.And the complex has been characterized with XRD and IR.     

由α-萘乙酸构筑的一维铜(Ⅱ)配位聚合物的合成、结构和性质研究

合成了一维聚合物[Cu(NAA)2]n(HNAA=α-萘乙酸),采用单晶X-射线、FTIR和元素分析对生成的晶体进行了结构表征。该聚合物属于正交晶系,Pbcn空间群,a=3.077 2(3)nm,b=1.272 56(11)nm,c=1.023 51(9)nm,V=4.008 0(6)nm3,Z=8。Cu髤的配位几何构型是五配位的扭曲四方锥,配体的羧基采用μ2-η1∶η1和μ3-η2∶η1两种不同的桥联配位模式,连结Cu髤离子形成1D链,1D链又被C-H-π作用力进一步连结形成2D层和3D固态超分子结构。磁性研究表明:在该聚合物中,相邻铜离子间存在反铁磁偶合作用。还对其热稳定性进行了研究。