NMR characterization of new 10-membered-ring macrolactones and dihydrobenzophenazine-5-one, oxidized derivatives of benzo[a]phenazines

Peroxidation of the phenazine of beta-lapachone using m-ClC6H4CO3H-CH2Cl2 furnished a macrolactone with a rigid 10-membered ring, and the corresponding N-oxide, along with a dihydrobenzophenazine-5-one. All of the new compounds were fully characterized by spectroscopic methods, with the unambiguous assignment of the hydrogens and carbon NMR signals for the N-oxide, with the aid of 2-D NMR, mainly COSY, HMQC, HSQC and HMBC. For the other two compounds some signals could not be assigned owing to their own intrinsic features.     

气相色谱-质谱联用法检测保健品中的违禁药物

近年来,随着社会消费水平的不断提高,保健品市场日益兴旺,但暴露出来的问题也十分严重。假冒配方、虚假广告、任意夸大其功效作用的宣传已为社会与公众所关注,而添加违禁合成药物、假化学成分达到或增加其功效作用的行为更具隐蔽性、欺骗性和危害性,为一般消费者所难以识别。因     

Chemiluminometric determination of carvedilol in a multi-pumping flow system

In this work a simple, fast, sensitive and selective flow-based procedure for the chemiluminometric determination of carvedilol, a recent non-cardioselective β-blocker with noteworthy antioxidant activity, is proposed. The developed methodology takes advantage of the antioxidant capacity of carvedilol to inhibit the chemiluminescence response resulting from the oxidation of luminol by hypochlorite, by acting as a hypochlorite scavenger. The analytical process was implemented in a multi-pumping flow system that employs multiple solenoid actuated micro-pumps as the only active components. These acted as solution insertion, propelling and commuting units assuring an easily controlled, low cost, compact and reliable analytical system.A linear working range for carvedilol concentrations ranging from 1.2 × 10⁻⁷ to 3.0 × 10⁻⁶ mol l⁻¹ (r > 0.999, n = 6), was obtained, with a detection limit of 8.7 × 10⁻⁹ mol l⁻¹. The system handles about 65 samples per hour yielding precise results (R.S.D. < 1.3%, n = 10). Recoveries within 95 and 104% were obtained.     

3-乙氧基-4-羟基苯乙醇酸在聚邻甲苯胺-Cu2+膜电极上的电氧化

采用循环伏安法制备了聚邻甲苯胺(POT)膜电极,再以浸泡吸附法在此膜中嵌入Cu2+,制成POT-Cu2+膜电极.研究了POT-Cu2+膜电极对3-乙氧基-4-羟基苯乙醇酸的电氧化行为,并讨论了影响电氧化活性的主要因素.结果表明,50℃下,在含有0.5mol.L-13-乙氧基-4-羟基苯乙醇酸的1.5mol.L-1氢氧化钠溶液中,POT-Cu2+膜电极具有高的电氧化活性和良好的稳定性.将该电极用于3-乙氧基-4-羟基苯乙醇酸电解氧化脱羧制备乙基香兰素,在0.55V(vsSCE)下恒电位电解1h,乙基香兰素的产率可达89%以上,电流效率达97%以上.     

单活泼氢手性配体生成的原位镁催化剂及其在不对称合成中的应用

本文对原位镁催化剂近年的工作进行了总结,对由单活泼氢手性配体生成的原位镁催化剂在不对称合成中的应用进行了系统归纳和分类。介绍了由单氮氢键、单酚羟基和单醇羟基构成的手性配体的设计和发展及其在原位镁催化剂中的应用,实现了多种类型的不对称催化反应过程和化学键的形成方式。对于原位镁催化策略的进一步探索,将有助于研究和推广更多类型廉价环保金属资源催化的化学转化过程。     

异核双金属探针在活细胞细胞核和线粒体中选择性定位DNA

用于实时成像活细胞DNA的细胞核探针是非常罕见的。通过Ru(N^N)₃、Ir(C^N)₂(N^N)、Re(CO)₃Cl(N^N)和Pt(C^N)(N^N)的结合,生成了4种异核双金属配合物：2种不同的功能金属位点被锚定在线性双齿螯和配体(N^N)-(N^N)的尾端,形成不对称哑铃状的双金属分子M₁-M₂,即Ru-Re、Ru-Pt、Ir-Re和Ir-Pt。Ru-Re和Ru-Pt的红色发射探针具有较大的斯托克斯位移、优异的核膜穿透能力、良好光稳定性的DNA结合能力。此外,Ru-Re和Ru-Pt探针的DNA成像可与专门用于活细胞细胞核DNA染色的Hoechst 33342商用染料相媲美,而Ir-Re和Ir-Pt探针直接靶向线粒体。不同探针的发光特性和选择性胞内定位高度依赖于在异核双金属配合物中的金属物种。