Controlling Metallophilic Interactions in Chiral Gold(I) Double Salts towards Excitation Wavelength‐Tunable Circularly Polarized Luminescence

Materials exhibiting excitation wavelength‐dependent photoluminescence (Ex‐De PL) in the visible region have potential applications in bioimaging, optoelectronics and anti‐counterfeiting. Two multifunctional, chiral [Au(NHC)₂][Au(CN)₂] (NHC=(4R,5R)/(4S,5S)‐1,3‐dimethyl‐4,5‐diphenyl‐4,5‐dihydro‐imidazolin‐2‐ylidene) complex double salts display Ex‐De circularly polarized luminescence (CPL) in doped polymer films and in ground powder. Emission maxima can be dynamically tuned from 440 to 530 nm by changing the excitation wavelength. The continuously tunable photoluminescence is proposed to originate from multiple emissive excited states as a result of the existence of varied Au^I???Au^I distances in ground state. The steric properties of the NHC ligand are crucial to the tuning of Au^I???Au^I distances. An anti‐counterfeiting application using these two salts is demonstrated.     

An Exceptional Peroxide Birefringent Material Resulting from d–π Interactions

Birefringent materials, which can modulate the polarization of light, are almost exclusively limited to oxides. Peroxides have long been overlooked as birefringent materials, because they are usually not stable in air. Now, the first peroxide birefringent material Rb₂VO(O₂)₂F is reported, the single crystals of which keep transparency after being exposed in the air for two weeks. Interestingly, Rb₂VO(O₂)₂F does not feature an optimal anisotropic structure, but its birefringence (Δn=0.189 at 546 nm) exceeds those of the majority of oxides. According to the first‐principles calculations, this exceptional birefringence should be attributed to the strong electronic interactions between localized π orbital of O₂^2? anions and V⁵⁺ 3d orbitals, which may be also favorable to the stability in the air for Rb₂VO(O₂)₂F. These findings distinguish peroxides as a brand‐new class of birefringent materials that may possess birefringence superior to the traditional oxides.     

手性配体在钯催化不对称碳氢键活化反应中的应用

目前,手性配体辅助钯催化的区域和对映选择性碳氢键活化是过渡金属催化的前沿领域.在过去的十年中,它作为一种越来越重要的合成工具,用于合成含有各种不对称元素(中心手性、轴手性和平面手性)的手性分子,也是快速构建各种碳碳键和碳杂原子键的最有效方法之一.本文介绍了一些典型手性配体在钯催化不对称sp2和sp3碳氢键活化/官能团化...     

Cryptotympana pustulata Extract and Its Main Active Component,Oleic Acid,Inhibit Ovalbumin-Induced Allergic Airway Inflammation through Inhibition of Th2/GATA-3 and Interleukin-17/RORγt Signaling Pathways in Asthmatic Mice

Cicadae Periostracum (CP), derived from the slough of Cryptotympana pustulata, has been used as traditional medicine in Korea and China because of its diaphoretic, antipyretic, anti-inflammatory, antioxidant, and antianaphylactic activities. The major bioactive compounds include oleic acid (OA), palmitic acid, and linoleic acid. However, the precise therapeutic mechanisms underlying its action in asthma remain unclear. The objective of this study was to determine the antiasthmatic effects of CP in an ovalbumin (OVA)-induced asthmatic mouse model. CP and OA inhibited the inflammatory cell infiltration, airway hyperresponsiveness (AHR), and production of interleukin (IL)7 and Th2 cytokines (IL-5) in the bronchoalveolar lavage fluid and OVA-specific imunoglobin E (IgE) in the serum. The gene expression of IL-5, IL-13, CCR3, MUC5AC, and COX-2 was attenuated in lung tissues. CP and OA might inhibit the nuclear translocation of GATA-binding protein 3 (GATA-3) and retinoic acid receptor-related orphan receptor γt (RORγt) via the upregulation of forkhead box p3 (Foxp3), thereby preventing the activation of GATA-3 and RORγt. In the in vitro experiment, a similar result was observed for Th2 and GATA-3. These results suggest that CP has the potential for the treatment of asthma via the inhibition of the GATA-3/Th2 and IL-17/RORγt signaling pathways.     

新型吡唑肟衍生物的设计、合成与杀虫活性研究

为寻找高效与低毒的吡唑肟活性物质,设计合成了9个未见文献报道的新型吡唑肟化合物,通过¹H NMR、¹³C NMR及元素分析等方法确证了其目标物的结构。初步生物活性测试数据显示,在500µg/mL浓度下,目标化合物6a~6i对粘虫均有较好的杀虫效果,其杀死率均为100%,与对照药啶虫丙醚的防效相当,值得进一步深入研究。     

基于铜金属有机配合物的热活化延迟荧光材料

具有热活化延迟荧光(thermally activated delayed fluorescence, TADF)特性的配合物可以同时利用单重态和三重态激子,因此发光量子效率较高,近年来受到广大科研工作者的关注。特别是铜金属有机配合物,最低单重态和最低三重态的能量差较小,又可以通过不同配体或取代基进行调节,所以具有较好TADF性能。本文根据配位原子的类型,汇总和分析了近5年具有TADF性质的铜配合物的结构特点和发光性能,并简要讨论了其在有机发光二极管(organic light-emitting diodes,OLEDs)中的潜在应用。     

气相色谱-负化学源质谱法测定禽蛋及蛋制品中氟虫腈及其代谢物

建立了气相色谱-负化学源质谱联用技术(GC-NCI-MS)测定禽蛋及蛋制品中氟虫腈及其3种代谢物残留量的方法。样品经乙腈提取,分散固相萃取技术QuEChERS净化,采用基质校正曲线外标法定量。在0.005~0.10mg/L范围内氟虫腈及其3种代谢物均呈现良好的线性关系,所有目标物的定量限均在0.025~0.10μg/kg范围内,均能满足国内外的限量要求。在0.1、2.0、4.0、20.0μg/kg 4个添加水平下,氟虫腈及其3种代谢物的平均回收率均处于87.0%~99.3%,RSD均≤12.7%,说明该法有较高的准确度和较好的稳定性。综上所述,该法灵敏度、准确度较高,精密度较好,可用于禽蛋及蛋制品中氟虫腈及其代谢物残留量的测定。     

A Novel Method for the Detection of Chlorpyrifos by Combining Quantum Dot-labeled Molecularly Imprinted Polymer with Flow Cytometry

Uniform-sized fluorescent molecularly imprinted polymers were prepared by one-step swelling and suspension polymerization, while chlorpyrifos, methacrylic acid, ethylene glycol dimethacrylate, and oil-soluble CdSe/ZnS quantum dots were used as the carrier, template molecule, functional monomer, cross-linker, and fluorophor, respectively. The morphology, adsorption dynamics, binding ability, and selectivity of quantum dot-labeled molecularly imprinted polymers were evaluated. The dosage of quantum dots for labeling the molecularly imprinted polymers was optimized. The results showed that the optimized dose of quantum dots was 200?µL using a concentration of 8.0?µM. The microsphere size was approximately 10?µm with a honeycombed surface. The quantum dot-labeled molecularly imprinted polymers had an even brightness and a high selectivity. In the presence of different concentrations of chlorpyrifos, a decrease in the fluorescence intensity of the quantum dot-labeled molecularly imprinted polymer was clearly identified by flow cytometry. The whole detection process was accomplished within 2?h including pretreatment. This method was used for the determination of chlorpyrifos in tap water samples.     

唾液酸衍生物的合成进展

唾液酸是一类九碳糖,主要以糖脂或者糖蛋白的形式广泛分布于哺乳动物组织中,是脊椎动物细胞表面最重要的单糖.唾液酸可修饰的位点较多,目前已发展出成千上万的非天然唾液酸衍生物用于分子成像.尽管如此,非天然糖代谢工程方法还处于发展的初期,很多方面亟待发展和完善.结合本课题组的研究成果,着重介绍了唾液酸衍生物的合成进展.     

4-二甲氨基黄酮衍生物的合成及其活性评价

设计合成了10个4-二甲氨基黄酮衍生物,产物结构均经1H NMR,ESI-MS和元素分析确认.采用噻唑蓝(MTT)法测试了化合物对HepG2(人肝癌细胞)的抑制作用,结果表明目标化合物在30μmol/L浓度下对HepG2细胞损伤均有一定的抑制作用,大部分化合物优于对照药物槲皮素,其中化合物5c,5e,5f和5j活性最强,抑制率分别为91.0%,90.1%,95.7%和92.1%,而且化合物5f在10μmol/L浓度下对HepG2的抑制率为93.1%,具有深入研究的价值.