Spectroscopic, and thermal studies of some new binuclear transition metal(II) complexes with hydrazone ligands containing acetoacetanilide and isoxazole

A new chelating ligand, 2-(2-(5-tert-butylisoxazol-3-yl)hydrazono)-N-(2,4-dimethylphenyl)-3-oxobutanamide (HL), and its four binuclear transition metal complexes, M-2(L)(2) (mu-OCH3)(2) [M = Ni(II), Co(II), Cu(II), Zn(II)], were synthesized using the procedure of diazotization, coupling and metallization. Their structures were postulated based on elemental analysis, H-1 NMR, MALDI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films of these complexes on K9 glass substrates were prepared using the spin-coating method and their absorption properties were evaluated. The thermal properties of the metal(II) complexes were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC. Different thermodynamic and kinetic parameters namely activation energy (E

Synthesis, spectroscopic and thermal properties of nickel (II)-azo complexes with blue-violet light wavelength

A novel azo dye containing isoxazole ring and beta-diketone derivative (TIAD) and its two nickel (II) complexes (Ni (II)-ETIAD and Ni (II)-HTIAD) were synthesized in order to obtain a blue-violet light absorption and better thermal stability as a promising organic storage material for next generation of high density digital versatile disc-recordable (HD-DVD-R) systems that uses a high numerical aperture of 0.85 at 405 nm wavelength. Their structures were confirmed on the basis of elemental analysis, MS, FT-IR, UV-Vis and magnetic data. Their solubility in 2,2,3,3-tetrafluoro-1-propanol (TFP) and absorption properties of thin film were measured. The difference of absorption maximum from the complexes to their ligands was discussed. In addition, the TG analysis of the complexes was also determined, and their thermal stability was evaluated. (C) 2004 Elsevier Ltd. All rights reserved.

Efficient synthesis and utilization of phenyl-substituted heteroaromatic carboxylic acids as aryl diketo acid isosteres in the design of novel HIV-1 integrase inhibitors

Three new types of aryl diketo acid (ADK) isosteres were designed by conversion of the biologically labile 1,3-diketo unit into heteroaromatic motif such as isoxazole, isothiazole, or 1H-pyrazole to improve the physicochemical property of ADK-based HIV-1

N-methyl-D-aspartate receptor-dependent long-term potentiation in CA1 region affects synaptic expression of glutamate receptor subunits and associated proteins in the whole hippocampus

Long term potentiation in hippocampus, evoked by high-frequency stimulation, is mediated by two major glutamate receptor subtypes, alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionate receptors and N-methyl-D-aspartate receptors. Receptor subunit compos

特异性干扰肽对海马突触可塑性的影响及其功能研究

在哺乳动物复杂的神经网络中，突触是信息传递的枢纽，其突触传递效能的持续性变化被称为突触可塑性（synaptic plasticity）。长时程增强（long-term potentiation，LTP）和长时程抑制（long-term depression，LTD）现象是两种经典的突触可塑性形式，被视作学习和记忆可能的物质基础，得到了广泛地关注。其中，海马CA1区谷氨酸能突触处的LTP和LTD目前研究得最为广泛。 α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid（AMPA）受体作为介导兴奋性谷氨酸能突触基础传递的主要受体，是海马CA1区LTP和LTD正常表达的必要条件。近期的研究表明，AMPA受体通过胞吞、胞吐及侧向移动等方式在细胞膜和细胞内进行着持续地循环。因此，通过调节AMPA受体的上、下膜，进而影响突触后膜上AMPA受体的数量，便能对LTP和LTD产生影响。在本研究中，我们利用生物信息学的手段，以AMPA受体为靶点，设计出了旨在特异阻断LTP或LTD的多肽。运用离体脑片全细胞记录方式，在海马CA1区证明了干扰肽Pep-A2能够特异地阻断LTP而不影响LTD，Pep-A3能够特异地阻断LTD而不影响LTP。并初步探究了其关键的作用位点，为进一步理解LTP和LTD具体的分子机理打下了基础。成瘾作为异常的学习记忆过程，势必涉及到突触可塑性的变化。而特异性地阻断LTP和LTD，对药物成瘾效果的影响却鲜有报道（Wang YT，2007）。在另一部分工作中，我们采用穿膜肽Tat-A2和Tat-A3，在吗啡条件化位置偏爱（morphine conditioned place preference，morphine CPP）模型小鼠的测试前进行系统给药，结果发现两种干扰肽均能阻断或损伤其CPP的表达过程。这一现象，提示我们LTP和LTD在条件化位置偏爱的表达过程中都是不可或缺的，同时也为人们更好地理解成瘾过程的机理，及开发专一有效的治疗药物提供了新的思路。