Anti-Neuroinflammatory Components from Clausena lenis Drake

Clausena lenis Drake (C. lenis) is a folk medicinal herb to treat influenza, colds, bronchitis, and malaria. The 95% and 50% ethanol extract of C. lenis showed significant nitric oxide (NO) inhibition activity in BV-2 microglial cells stimulated by lipopolysaccharide (LPS). Bio-guided isolation of the active extract afforded five new compounds, including a chlorine-containing furoquinoline racemate, (±)-claulenine A (1), an amide alkaloid, claulenine B (2), a prenylated coumarin, claulenin A (3), a furocoumarin glucoside, clauleside A (4), and a multi-prenylated p-hydroxybenzaldehyde, claulenin B (5), along with 33 known ones. Their structures were determined via spectroscopic methods, and the absolute configurations of new compounds were assigned via the electronic circular dichroism (ECD) calculations and single-crystal X-ray diffraction analysis. Compounds 2, 23, 27, 28, 33, and 34 showed potent anti-neuroinflammatory effects on LPS-induced NO production in BV-2 microglial cells, with IC₅₀ values in the range of 17.6–40.9 μM. The possible mechanism was deduced to interact with iNOS through molecular docking.     

Regioselective B—H/C—H Bond Activation at Azo-Substituted Carboranes Induced by Half-Sandwich Iridium(III)Complex

We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an azo directing group. Through this strategy, a series of mononuclear, trinuclear and tetranuclear cyclometalated iridium complexes containing Cp*Ir—B or Cp*Ir—C bonds were successfully isolated in a high yield. In this work, efficient routes are developed through one-pot reactions to prepare polynuclear organometallic complexes.     

二氧化硅-聚硅氧烷负载硫杂-15-冠-5铂、铑配合物的合成及其催化硅氧化性能

6－(ω'-十一碳烯氧甲基)-1-硫杂-4,7,1O,13-四氧杂环十五烷与三乙氧基硅烷进行硅氢加成,产物依次以气相法二氧化硅固载、氯亚铂酸钾或三氯化铑络合,合成了相应的二氧化硅-聚硅氧烷负载硫杂-15-冠-5-铂、铑配合物,并研究了它们在烯烃与三乙氧基硅烷的硅氢加成反应中的催化性能.结果表明,二者均为硅氢加成反应的高效催化剂.     

Synthesis of 6-aryl-3-cinchophenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles

In recent years, fused heterocycles have been found to possess many unique properties in synthesis and pharmacology. Especially, 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives have been attracting much attention of chemists and pharmacologists because of their broad-spectrum biological activities such as antibacterial¹, hypotensive and CNS depressant² activities. We have prepared some 3,6-substituted 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles and found that these compounds exhibited antimacrobial, insecticidal and promote plant growth.^3-5 Cinchophen had been used widely as medicine in clinic,but has been obsolete in recent years due to its by-effect. In order to seek for other uses of cinchophen, as a continuation of our preceeding studies, we used cinchophen as the starting material to synthesize ten new 6-aryl-3-cinchophenyl-l,2,4-triazolo[3,4-b]-l,3,4-thiadiazoles 5a-j. Compound 1 was prepared by the reaction of cinchophen and ethanol in the presence of sulfuric acid. 1 then reacted with hydrazine hydrate in absolute ethanol to give 2 which yielded 3 on treatment with CS₂ and KOH. On refluxing of 3 with excess hydrazine hydrate, 4 was obtained. 4 reacted with various substituted benzoic acids in the presence of POCl₃ to afifort 5a-j.     

Studies on Semisynthesis and Antibacterial Activities of 7β-(l-aryl-5-methyl-l,2,3-triazol-4-acylamido)-3-(2-substituted-1,3,4-oxadizol-5-thiomethyl) Cephalosporin

Cephalosporin derivatives have been a subject in the field of β-lactam antibiotics due to their broad-spectrum biological activities in recent years. Chemical manipulation of the C-3 and 7β-position in the cephalosporin molecule has resulted in the discovery of numerous novel antibiotics. In general, the C-3 position of the cephalosporin were substituted with heterocyclyl sulfurs or nitrogens and the 7β-position were substituted with heterocycles or aryl¹. The side chain at 7β-position determined their antibacterial activities and antibacterial spectrum, moreover, the substituted groups at C-3 position not only affect pharmacokinetic properties, but antibacterial activities and antibacterial spectrum as well.² Roche Reiner company found that the activities of cephalosporin can be improved by changing the R of RCONH- at 7β-position of 7ACA and introducing various thioazoleheterocycles into C-3 position of it.³ It is no doubt that these heterocycles increased their activities and wided their antibacterial spectrum. In the course of our studies on the modification of cephalosporin, our efforts have been focused on introducing heterocycles into C-3 and 7β-position of 7ACA with the hope of achieving better antibiotics.     

核苷磷酸盐对含双芘侧链荧光敏感器化合物的荧光猝灭与分子识别

合成了一种在水溶液中对核苷磷酸盐ATP,ADP,AMP阴离子具有识别能力的荧光化学敏感器分子---化合物1。通过检测化合物1在水溶液中芘激基缔合物荧光发射强度随核苷磷酸盐、腺嘌呤等的加入而引起的变化,求出不同核苷磷酸盐及腺嘌呤对芘激基缔合物荧光发射的猝灭常数,并进行了比较研究。利用荧光发射强度随不同核苷磷酸盐引入而发生的变化计算出化合物1对不同核苷磷酸盐进行配位的配位稳定常数。结果表明所合成的化合物1对ATP有着良好的识别力选择功能。此外,还利用分子力学的计算方法对化合物1及其与核苷磷酸盐形成配合物后的分子构象及几何尺寸作了计算,并结合实验结果进行了初步讨论。     

金属调控的2，4，6-三(2-吡啶基)-1，3，5-三嗪基配合物的光致变色性能

在溶剂热条件下,将2,4,6?三(2?吡啶基)?1,3,5?三嗪(2?TPT)、2,5?呋喃二羧酸(2,5?H₂FCA)分别与不同类型的金属硝酸盐(Zn、Cd和Mn)进行组装,得到了3个2?TPT基配合物:[Zn(2?TPT)(2,5?FCA)](1)、[Cd(2?TPT)(2,5?FCA)]·1.5H₂O(2)和[Mn(2?TPT)(2,5?FCA)](3)。通过单晶X射线衍射、粉末X射线衍射、FT?IR、UV?Vis、差热-热重、电子顺磁共振和X射线光电子能谱对1~3的结构和光致变色性能进行了表征,并详细地探究了其光致变色机理。配合物1~3表现出明显差异的光诱导分子间电子转移和光致变色性能,主要体现在光响应速率和颜色对比度2个方面。其中,1的光致变色性能明显优于2,而3不具有光致变色行为。这种明显差异的光致变色行为,主要归因于不同类型的金属及其配位模式的差异所引起的不同晶体堆积模式和电子给体-受体间相对位置关系(界面关系),体现出了金属对于光致变色性能的调控作用。     

MXene在癌症精准诊疗中的应用

癌症是威胁人类健康的第二号杀手,精准的筛查诊断技术和高效的治疗手段是治愈癌症的关键。纳米技术的迅猛发展为癌症的诊疗带来了新的思路和希望。新型二维材料MXene,具有大的比表面积、高的导电性、良好的亲水性和优异的生物相容性,可以作为优良的基底材料构建生物传感平台,并通过兼容其他材料,形成具有高催化性能的MXene复合物,从而实现癌症生物标志物的精准检测。此外,MXene组分可调,且在可见光到红外区域具有强烈吸收和高光热转换效率,是理想的肿瘤光热治疗(PTT)试剂。迄今为止,关于 MXene在癌症诊疗领域的专题论述鲜有报道。鉴于此,本文根据癌症生物标志物进行分类,综述了近年来基于MXene的生物传感平台在癌症标志物检测中的应用,并归纳了不同的MXene材料在PTT领域的最新研究进展,进而提出MXene在癌症诊疗领域面临的挑战和未来发展趋势。