基于硝基咪唑衍生物的Cu(Ⅱ)、Ag(Ⅰ)配合物的合成、晶体结构及生物活性

设计、合成了硝基咪唑衍生物N,N'-二甲基-5-硝基-2,2'-联咪唑(L)的过渡金属配合物[Cu(L)(Ac)2]2(1)和[Ag(L)(NO3)]·H2O(2).X射线单晶衍射分析表明配合物1是一个醋酸根桥联的五配位双核Cu(Ⅱ)浆轮笼型配合物.通过元素分析、紫外光谱、红外光谱、固体荧光光谱、电喷雾质谱、摩尔电导率...     

含喹唑啉硫醚的杨梅素衍生物的设计、合成及生物活性研究

以杨梅苷为原料,通过活性拼接,设计并合成一系列含喹唑啉硫醚的杨梅素衍生物,其结构通过1H NMR、13CNMR、19F NMR和HRMS进行确证.生物活性测试结果表明,该类化合物对水稻白叶枯病菌(X.Oryzae)、柑橘溃疡病菌(X.Citri)和烟草青枯病菌(R.Solanacearum)表现出一定的抑制活性.其中,...     

Antibacterial Activity of a Promising Antibacterial Agent: 22-(4-(2-(4-Nitrophenyl-piperazin-1-yl)-acetyl)-piperazin-1-yl)-22-deoxypleuromutilin

A novel pleuromutilin derivative, 22-(4-(2-(4-nitrophenyl-piperazin-1-yl)-acetyl)-piperazin-1-yl)-22-deoxypleuromutilin (NPDM), was synthesized in our laboratory and proved excellent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). In this study, more methods were used to further study its preliminary pharmacological effect. The antibacterial efficacy and toxicity of NPDM were evaluated using tiamulin as the reference drug. The in vitro antibacterial activity study showed that NPDM is a potent bactericidal agent against MRSA that induced time-dependent growth inhibition and a concentration-dependent post-antibiotic effect (PAE). Toxicity determination showed that the cytotoxicity of NPDM was slightly higher than that of tiamulin, but the acute oral toxicity study proved that NPDM was a low-toxic compound. In an in vivo antibacterial effect study, NPDM exhibited a better therapeutic effect than tiamulin against MRSA in a mouse thigh infection model as well as a mouse systemic infection model with neutropenia. The 50% effective dose (ED₅₀) of NPDM in a Galleria mellonella infection model was 50.53 mg/kg. The pharmacokinetic properties of NPDM were also measured, which showed that NPDM was a rapid elimination drug in mice.     

Expanding the Chemical Space of Tetracyanobuta-1,3-diene (TCBD) through a Cyano-Diels-Alder Reaction: Synthesis,Structure, and Physicochemical Properties of an Anthryl-fused-TCBD Derivative

Tetracyanobuta-1,3-diene (TCBD) is a powerful and versatile electron-acceptor moiety widely used for the preparation of electroactive conjugates. While many reports addressing its electron-accepting capability have appeared in the literature, significantly scarcer are those dealing with its chemical modification, a relevant topic which allows to broaden the chemical space of this interesting functional unit. Here, we report on the first example of a high-yielding cyano-Diels-Alder (CDA) reaction between TCBD, that is, where a nitrile group acts as a dienophile, and an anthryl moiety, that is, acting as a diene. The resulting anthryl-fused-TCBD derivative, which structure was unambiguously identified by X-ray diffraction, shows high thermal stability, remarkable electron-accepting capability, and interesting electronic ground- and excited-state features, as characterized by a thorough theoretical, electrochemical, and photophysical investigation. Moreover, a detailed kinetic analysis of the intramolecular CDA reaction transforming the anthryl-TCBD-based reactant into the anthryl-fused-TCBD product was carried out at different temperatures.     

Fractional Dynamics of HIV with Source Term for the Supply of New CD4+ T-Cells Depending on the Viral Load via Caputo–Fabrizio Derivative

Human immunodeficiency virus (HIV) is a life life-threatening and serious infection caused by a virus that attacks CD4+ T-cells, which fight against infections and make a person susceptible to other diseases. It is a global public health problem with no cure; therefore, it is highly important to study and understand the intricate phenomena of HIV. In this article, we focus on the numerical study of the path-tracking damped oscillatory behavior of a model for the HIV infection of CD4+ T-cells. We formulate fractional dynamics of HIV with a source term for the supply of new CD4⁺ T-cells depending on the viral load via the Caputo–Fabrizio derivative. In the formulation of fractional HIV dynamics, we replaced the constant source term for the supply of new CD4+ T-cells from the thymus with a variable source term depending on the concentration of the viral load, and introduced a term that describes the incidence of the HIV infection of CD4+ T-cells. We present a novel numerical scheme for fractional view analysis of the proposed model to highlight the solution pathway of HIV. We inspect the periodic and chaotic behavior of HIV for the given values of input factors using numerical simulations.     

稀土穴状荧光配合物的合成与光谱性质

以2,6-二甲基吡啶-3,5-二甲酸二乙酯为起始原料,经N-溴代丁二酰亚胺(NBS)溴代、亲电取代反应合成了时间分辨荧光免疫分析双功能螯合剂2,6-{N,N′,N,N′-[二(2,2′-联吡啶-6,6′-二甲基)]二(氨甲基)}-吡啶-3,5-二羧酸二乙酯。经差热分析仪(DTA)、傅里叶变换红外光谱仪(FTIR)、核磁共振波谱仪(1 H NMR)、质谱仪(MS)等技术手段表征确认了化合物结构和性能。对该化合物与铕离子形成螯合物的荧光性质研究表明:激发光谱波长范围较宽,激发峰值为322nm;荧光发射峰为597nm(~5D_0-~7F_1)、618nm(~5D_0-~7F_2);荧光寿命为918μs;量子产率Φ=0.249。     

二茂铁衍生物L—B膜修饰SnO2电极的性能

用外层单电子快速转移的氧化还原剂二茂铁及其衍生物修饰电极,在电极/溶液界面作为电子传递的中介物,可使电极上进行的慢反应得到加速、起中介催化作用。目前研究较多的是共价键合和高分子膜的修饰,其他方式的修饰报道不多。用能实现分子有序化排列的L-B膜技术进行氧化还原电活性分子的修饰电极还未见报道。我们用L-B膜技术在SnO_2电极上修饰了二茂铁的衍生物-硬脂酸二茂铁酯(FcOCOC_(17)H_(35))双亲化合物,曾研究了修饰膜的电化学可逆行为和稳定性。本文研究硬脂酸二茂铁酯L-B膜修饰的SnO_2电极     

Construction of β-Phenylalanine Derivatives through Pd-Catalyzed,C(sp2)−H (ortho) Functionalization

This paper describes the Pd(II)-catalyzed, picolinamide-directing-group-aided C(sp²)−H (ortho) functionalization of racemic and enantiopure β-phenylalanines and 3-amino-3-phenylpropanols (1,3-amino alcohols). The C(sp²)−H (ortho) functionalizations including arylation, bromination, iodination, and alkoxylation were attempted. The C(sp²)−H (ortho) arylation reactions gave biaryl or terphenyl-type β-phenylalanine scaffolds, halogenation and methoxylation reactions gave ortho C−H halogenated or methoxylated β-phenylalanines. Additionally, the C−H arylation of an ortho-methyl substituted β-phenylalanine containing both C(sp²)−H and remote C(sp³)−H bonds was investigated. β-Phenylalanine is an arylated β-amino acid motif present in various natural products, bioactive molecules, and β-peptides and it is a precursor to medicinally active compounds. Accordingly, this work contributes to the expansion of the library of unnatural β-phenylalanine (β-amino acid) derivatives through site-selective C−H functionalization.     

一种罗丹明6G类“Off-On”型Fe3+比色荧光探针

设计合成了一种基于罗丹明6G的新型比色荧光探针(RG),并通过核磁共振氢谱、碳谱和质谱进行了表征。该探针在pH=6的Tris-HCl缓冲溶液中可与Fe³⁺作用,溶液由无色变为粉红色,在530nm处产生强吸收,同时在557nm处发射强荧光。通过金属离子选择性实验,发现探针RG对Fe³⁺有高选择性;此外,探针溶液530nm的吸光度和557nm的荧光强度与Fe³⁺浓度呈良好的线性关系,检出限分别为1.26和3.87μmol/L。Job’s曲线分析表明探针分子与Fe³⁺的反应摩尔比为1∶1。此外,以乙二胺四乙酸为络合剂实现了探针分子的重复使用。该探针可用于实际水样中Fe³⁺的精准检测。     

Development of a Novel Silver-based Sensing Platform for Detecting Superoxide Anion Released from HeLa Cells Directly

Reactive oxygen species (ROS) have become the focus of research in recent years because they are closely related to many diseases, including cancer. Therefore, detection of ROS released from cells is of particular importance. In this work, the nanocomposites with uniform dispersion of silver nanoparticles were obtained through pyrolyzing a novel silver-based metal-organic framework. As the main active component of the composition, AgNPs can effectively catalyze the decomposition of hydrogen peroxide produced by superoxide anion (O₂ ⋅ ⁻) disproportionation. Then, we designed a superoxide anion sensor (AgNPs@C/GCE) using the above nanocomposite for the first time. The prepared sensor presented excellent catalytic ability and satisfactory detection performance towards O₂ ⋅ ⁻ with a detection range as wide as eight orders of magnitude and a lower detection limit of 1.011×10⁻¹³ M (S/N=3). Furthermore, the sensor can directly measure O₂ ⋅ ⁻ released by human cervical cancer cells (HeLa) under both the normal condition and the inducement by malonic acid. In addition, we explored the effects of different concentrations of stimuli on cells. The results illustrated the high dose malonic acid can cause oxidative stress on cells. Thus, this work has the tremendous potential applications to diagnosis of diseases related to ROS.