A new biomarker of protein oxidation degree and site using angiotensin as the target by MS

Hydroxyl radicals generated from Fenton reaction were used to damage the angiotensin. The oxidative damage degree and sites of peptides were measured by HPLC–MS and MS/MS. Experimental results proved that the oxidative damage degree increased with longer reaction time. The results also showed that the side chains of phenylalanine and tyrosine in angiotension can be attacked by hydroxyl radicals to form the oxidative products. A new strategy was established to monitor the oxidative degree and sites of peptides and laid the foundation for protein oxidation. This method can be used to investigate the mechanism of protein oxidative damage caused by oxidative stress which is induced by environmental pollutants and physiological activities. There will also be a wide application in the research of pathogenesis of some disease related to oxidative stress.     

实时直接分析质谱的原理及应用

新型常温常压离子化技术是近几年质谱学领域的一个研究热点。实时直接分析(direct analysis in real time,DART)作为该技术的一种,自2005年首次报道以来,已被应用于不同样品的分析。本文介绍了DART技术的发展过程、离子化机理以及影响DART离子化效率的参数,综述了其在活体果蝇费洛蒙检测、假药识别、墨水成分分析等方面的应用,并在结论部分对其应用前景进行了展望。     

实用型简易激光诱导荧光检测器的研制及性能测试

基于正交型结构,研制了一种简易实用的高效液相色谱激光诱导荧光检测器。以930荧光光度计为骨架,用岛津RF-535荧光检测池,配以自制可调稳压电源,分别以波长532am和405nm的自制激光器为激发光源,以罗丹明B和荧光素为荧光试剂评价体系的性能。罗丹明B的检出限为2．0×10^-8mol／L（S／N〉10）,荧光素的检出限为3．0×10^-10mol／L（S／N〉10）。测试结果表明该检测器达到了设计要求,具有足够的实用灵敏度和较宽的线性范围。     

1,3,5-三硝基-六氢化-1,3,5-三嗪-2(1H)-酮(Keto-RDX)新法合成、晶体结构和热性能研究

研究了1,3,5-三硝基-六氢化-1,3,5-三嗪-2(1H)-酮(Keto-RDX)的合成新方法,以乌洛托品和硝基胍为原料,通过Mannich反应得到2-硝亚胺基-六氢化-1,3,5-三嗪盐酸盐(NIHT·HCl),用HNO3/AC2O硝化可得Keto-RDX,并采用核磁共振、红外、质谱以及元素分析等进行了结构表征.培养了Keto-RDX单晶,晶体结构解析表明:晶体属于正交晶系,空间群Pnma,晶胞参数a=1.0057(17)nm,b=1.3483(2)nm,c=0.5982(10)nm,V=0.8112(2)nm3,Z=4,Dc=1.933 g/cm3,μ=0.188 mm-1,F(000)=480.差示扫描量热(DSC)法和热失重(TG/DTG)法分析表明,Keto-RDX分解峰温为211.4℃(DSC),在185.00～202.79℃为固相分解阶段,峰温为198.61℃,质量损失为21.45%,在202.79～230.00℃为液相分解阶段,质量损失为77.83%,峰温为213.78℃,热稳定性较RDX差.     

Controlled functionalization of gold nanoparticles through a solid phase synthesis approach

A novel solid phase synthetic strategy was developed in this work for controlled functionalization of gold nanoparticles.     

Doubly stereocontrolled asymmetric Michael addition of acetylacetone to nitroolefins promoted by an isosteviol-derived bifunctional thiourea

A novel class of chiral bifunctional thioureas bearing a chiral lipophilic beyerane scaffold and a tertiary amino group was designed and prepared. The thioureas were proven to be effective for catalyzing the doubly stereocontrolled asymmetric Michael addition between acetylacetone and nitroolefins. The corresponding adducts were obtained in high yields (up to 95%) and with good to excellent enantioselectivities (up to 97%). In addition, the reaction of tert-butyl acetoacetate and trans-β-nitrostyrene also proceeded smoothly with good enantioselectivity.     

Achillinin B and C,new sesquiterpene dimers isolated from Achillea millefolium

Two novel sesquiterpene dimers, achillinin B and C, were isolated from the flowers of Achillea millefolium. The structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of achillinin B and C by Diels–Alder reaction of the corresponding guaiane sesquiterpenoids is also discussed.     

Radical cation salt induced Povarov reaction between iminoethyl glyoxylate and N-vinylamides: synthesis of quinoline-2-carboxylate derivatives

A domino process between iminoethyl glyoxylate and N-vinylamides was achieved under the catalytic radical cation salt induced conditions, producing a series of quinoline-2-carboxylates. N-Vinylamides were involved as an acetylene equivalent. A possible mechanism was proposed to rationalize the formation of the products.     

Friedel–Crafts alkylation between chalcone epoxides and heteroarenes induced by triarylaminium salt

Triarylaminium salt was disclosed as a highly efficient nonmetallic initiator for the Friedel–Crafts reaction between chalcone epoxides and heteroarenes to construct a series of complex β-heteroaryl α-ketols in mild conditions and with good yields. Chalcone epoxides were presented as valuable halogen-free pre-electrophile in Friedel–Crafts alkylation through the formation of the stabilized benzylic cation intermediates. A plausible radical cation chain mechanism was also proposed.     

后处理对TiO_2纳米薄膜的表面结构和光催化活性的影响

半导体TiO2光催化材料对环境中各种污染物的明显去除效果已引起人们的广泛关注犤1～6犦。在普通钠钙玻璃表面涂制高光催化活性的TiO2纳米薄膜,制成环保建筑材料,不仅可以自洁玻璃表面,而且可以用于净化空气、处理废水等。但由于在热处理过程中玻璃基体内的Na+离子扩散到薄膜表面,形成光生电子和空穴的复合中心,使TiO2纳米薄膜的光催化活性大大降低犤7～10犦。为了减少玻璃中Na+离子对TiO2薄膜光催化活性的有害影响,Paz等犤8犦研究了将钠钙玻璃浸入酸溶液中,使玻璃表面的钠离子被酸中的氢离子置换出来;在玻璃表面形成SiO2凝胶层,以便阻…