Synthesis,characterization, and biological activity of [2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate and its derivatives

A new type of methacrylate monomer, [2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate (APEMA), was synthesized. The oxime, 2,4‐dinitrophenylhydrazone, and thiosemicarbazone derivatives of poly{[2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate} [poly(APEMA)] were prepared with hydroxylamine hydrochloride, 2,4‐dinitrophenylhydrazine, and thiosemicarbazone hydrochloride, respectively. The radical homopolymerization of APEMA was performed at 65 °C in a 1,4‐dioxane solution with benzoyl peroxide as an initiator. The monomer and its homopolymer were characterized with Fourier transform infrared and NMR techniques. The thermal stabilities of poly(APEMA) and its derivatives were investigated with thermogravimetric analysis and differential scanning calorimetry. The ultraviolet stability of the polymers were compared. The solubility and inherent viscosity of the polymers were also determined. The number‐average and weight‐average molecular weights and polydispersity index of the polymers were determined with gel permeation chromatography. The antibacterial and antifungal effects of the monomer and the polymer and its derivatives were also investigated on various bacteria and fungi. The activation energies of the thermal degradation of the polymers were calculated with the Ozawa method. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3157–3169, 2004     

Synthesis of acetone oxime through acetone ammoximation over TS-1

The ammoximation of acetone to acetone oxime with 30 wt.% hydrogen peroxide over TS-1 has been studied. The conversion of acetone and the selectivity to acetone oxime can reach 99% and 94%, respectively. The by-products are the corresponding hydrazone, imine and small amounts of unidentified compounds. The influence of various parameters such as solvent, temperature, amounts of catalyst and the NH₃ to acetone molar ratio were investigated. This revised version was published online in August 2006 with corrections to the Cover Date.     

环己酮肟在改性氧化锆催化剂上的Beckmann重排反应Ⅱ．影响重排反应的若干因素

环己酮肟在改性氧化锆催化剂上的Ｂｅｃｋｍａｎｎ重排反应Ⅱ．影响重排反应的若干因素程时标徐柏庆唐守平蒋山蔡天锡王祥生（大连理工大学化工学院化学系，大连１１６０１２）关键词氧化硼，氧化锆，负载型催化剂，环己酮肟，Ｂｅｃｋｍａｎｎ重排反应，己内酰胺前文［１...     

含甲硫基和肟醚基的N-甲氧基氨基甲酸酯类化合物的合成及生物活性研究

为了寻找高效、低毒的农药, 设计合成了一系列新的含甲硫基和肟醚基的N-甲氧基氨基甲酸酯类化合物5a～5q, 其结构经IR, ¹H NMR, LC/MS和元素分析确认. 生物活性测定表明, 部分化合物在50 mg/L下对稻瘟病菌(Pyricularia oryzae)、灰霉病菌(Botrytis cinerea)、水稻纹枯病菌(Rhizoctonia solani)和小麦白粉病菌(Blumeria griminis)有很好的抑菌活性.     

Simultaneous Determination of Platinum and Rhodium with Hydroxylamine and Acetone Oxime by Catalytic Adsorptive Stripping Voltammetry (CAdSV)

This paper describes a very sensitive catalytic adsorptive stripping voltammetry (CAdSV) procedure for the simultaneous determination of traces of platinum and rhodium in new supporting electrolyte containing hydroxylamine or acetone oxime and formaldehyde in sulfuric acid medium. Platinum and rhodium were pre‐accumulated simultaneously and after 120 s of accumulation time at 0.0 V, the achieved detection limits were equal 0.1 ng L^?1 and 0.2 ng L^?1 for platinum and rhodium respectively in the presence of acetone oxime and 0.6 ng L^?1 and 0.2 ng L^?1 for platinum and rhodium respectively in the presence of hydroxylamine. Described reagents were successfully applied to the determination of platinum and rhodium in plant material. Inductively coupled plasma mass spectrometry (ICP MS) was used as a reference method to the CAdSV measurements.     

Synthesis of 3-amino-5-nitrobenzaldehyde oxime and its conversion into 3,4-bis(3-amino-5-nitrophenyl)furoxan and isomeric 3(4)-(3-amino-5-nitrophenyl)-4(3)-nitrofuroxans

The oxime of the hitherto unknown 3-amino-5-nitrobenzaldehyde was synthesized by the reaction of 3-amino-5-nitrobenzaldehyde phenylhydrazone with excess of (NH₂OH)₂·H₂SO₄. The oxime obtained was used as the starting compound for the synthesis of novel diaryl- and arylnitrofuroxans. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2232–2235, December, 1997.     

B2O3/TiO2-ZrO2催化环己酮肟气相Beckmann重排反应研究 Ⅰ.B2O3含量的影响

 制备了不同B2O3含量（0～20％）的B2O3／TiO2－ZrO2固体酸催\r\n化剂，用XRD，FT－IR，N2吸附及NH3－TPD等方法测定了其结构、比表\r\n面积、孔分布和表面酸性．结果表明，当B2O3含量较低（≤5％）时，\r\n催化剂呈无定形态，样品中的B2O3主要以BO4结构存在．当B2O3含量较\r\n高（≥8％）时，催化剂中的TiO2－ZrO2以ZrTiO4晶相存在，分散于Ti\r\nO2－ZrO2表面的B2O3主要以玻璃体形式和BO3结构存在．随着B2O3含量\r\n的增加，催化剂的比表面积减小，孔径增大．300℃下的环己酮肟气相\r\nBeck－mann重排反应结果表明，随着B2O3含量的增加，己内酰胺的选择\r\n性逐渐增大，而己内酰胺的收率在B2O3含量为12％时达到最大值．讨论\r\n了B2O3／TiO2－ZrO2的催化性能与其表面酸性及孔径大小的关系．     

α-单取代环十二酮肟及缩氨基硫脲的合成及晶体结构

单晶X射线衍射分析表明, α-单取代环十二酮与氨衍生物羟胺和氨基硫脲发生缩合反应得到两种母体构象均为[3333], 而取代基为边外向或角反向的α-单取代环十二酮肟或缩氨基硫脲. 利用底物的“角位羰基参与反应”原理, “记忆效应”及进攻试剂与底物是否形成氢键解释了这一实验结果. 通常情况下, 试剂从空间障碍小的一面进攻羰基而生成α-角反取代环十二酮肟或缩氨基硫脲. 当试剂与底物的取代基之间能够形成分子间氢键时, 则生成α-边外取代环十二酮肟或缩氨基硫脲.     

Synthesis of branched oxime-linked peptide mimetics of the MUC1 containing a universal T-helper epitope

Our goal was to develop mimics of MUC1, highly immunogenic to induce an efficient immune response against the tumor-associated form of MUC1, and sufficiently different from the natural antigen to bypass the tolerance barrier in humans. With the aim of obtaining a well-defined peptide construct as a means of evoking the precise immune responses required in immunotherapy, we synthesized artificial mimics of the MUC1 protein composed of two MUC1 repeat units of inverse orientation and a universal T-helper epitope. To synthesize these heteromeric peptide constructs, we followed a convergent approach using chemoselective ligation based on oxime chemistry. A stem peptide was first synthesized bearing two orthogonally masked aldehydes. After successive deprotection, two oxime bonds can be specifically generated. The proposed strategy proved to be concise and robust, and allowed the synthesis of the tri-branched protein in a very satisfactory yield. The different constructs were tested for their ability to generate antibodies able to recognize the MUC1 protein.     

Electrospray tandem mass spectrometric analysis of zeaxanthin and its oxidation products

Carotenoids have been implicated in protection of the eye from light-mediated photo-toxicity caused by free radicals. Under conditions of normal oxidative stress the carotenoids serve as protective antioxidants; however, when the oxidative stress exceeds the antioxidant capacity, carotenoids can be oxidized into numerous cleavage products. The determination and identification of oxidized carotenoids in biological samples remains a major challenge due to the small sample size and low stability of these compounds. We investigated the reaction of various zeaxanthin cleavage products with O-ethyl hydroxylamine to evaluate their levels in a biological sample. For this, a sensitive and specific electrospray tandem mass spectrometry (ESI-MS/MS) was developed, avoiding the classical lower sensitive and specific HPLC-UV and fluorescence absorption methods. Protonated molecules [M + H](+) of carotenoids upon collision-induced dissociation produced a number of structurally characteristic product ions. A series of complicated clusters of product ions differing in 14 (CH(2))and 26 (C(2)H(2))Da was characteristic of the polyene chain of intact carotenoids. All carotenoid ethyl oximes of zeaxanthin cleavage products were characterized by the losses of 60 and 61 Da in their MS/MS spectra. Through the application of the LC/MS/MS method, we identified two oxime derivatives of 3-hydroxy-beta-ionone and 3-hydroxy-14'-apocarotenal with protonated molecules at m/z 252 and m/z 370 respectively, in a human eye sample.