区域选择性Michael/Aldol串联反应合成新型1′-茚醇拼接3-氧化吲哚类化合物

以3-烯烃氧化吲哚为起始原料,甲苯为溶剂,与丙二腈或腈基乙酸乙酯发生区域选择性Michael/Aldol串联反应,合成了6个新型的1′-茚醇拼接3-氧化吲哚类化合物,收率73%~90%, dr高达10/1,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI-TOF）表征。     

新型双螺环吡咯酮氧化吲哚并二氢色原酮类化合物的合成

以色酮3-羟甲基为原料,在4-二甲氨基吡啶(DMAP) 催化下与(Boc)₂O反应生成中间体A; A在三级胺DABCO催化下与3-异硫氰酸酯氧化吲哚发生Michael加成环化反应,合成了11个未见文献报道的双螺环吡咯酮氧化吲哚并二氢色原酮类化合物(3a~3k)，收率70%~87%， dr值为2/1~4/1,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI-TOF）表征。     

四苯乙烯基铂炔化合物的合成及发光性能

以4,4’-二溴二苯甲酮为原料,经缩合反应、Sonogashira偶联等反应合成了化合物3。以三联吡啶与四氯铂酸钾等为原料合成了化合物5,化合物5与化合物3通过Cu(I)催化的脱氯化氢反应得到目标化合物6,产率48%,其结构经¹H NMR,¹³C NMR和HR-MS（ESI）表征。吸收光谱和荧光光谱研究结果表明：化合物3在四氢呋喃/水体系中具有明显的AIE现象;而化合物6在二甲基亚砜/二氯甲烷体系中,随着二氯甲烷含量的增加荧光先增强后淬灭。      

新型螺环吡咯酮双氧化吲哚类化合物的无催化剂合成及其抗白血病活性

以3-异硫氰基氧化吲哚与3-丙二腈缩合的3-烯氧化吲哚为原料,乙腈为溶剂,在无催化剂存在的条件下于室温发生[3+2]环加成反应,合成了6个新型的螺环吡咯酮双氧化吲哚类化合物(3a~3f),产率91%~95%,dr 17/1~>20/1,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI-TOF）表征。采用MTT法研究了3a~3f对人白血病细胞(K562)的体外抗肿瘤活性。结果表明：化合物3c对K562具有明显的抑制活性（IC₅₀为36.3 μM）,与阳性对照药顺铂接近。     

异戊烯基查尔酮的合成与抗肿瘤活性

以2,4,6-三羟基苯乙酮为原料,依次经亲核取代、重排、羟醛缩合、水解等反应,合成了15个异戊烯基查尔酮类化合物（6a~6i和9a~9f）,其结构经¹H NMR,¹³C NMR和ESI-MS等表征。用MTT法评价了目标化合物对乳腺癌细胞（MDA-231）、前列腺癌细胞（LNCAP）、人肺癌细胞（A549）、肾癌细胞（A498）和宫颈癌细胞（Hela）增殖的抑制活性。结果表明：化合物6h、 6i和9a对肾癌细胞（A498）具有一定的抑制活性,在5 µmol/L浓度下抑制率分别达到了59.12%、 49.82%和50.95%;化合物6h和6i对宫颈癌细胞（Hela）的抑制率可达59.19%和41.87%;化合物6h和6i对人肺癌细胞（A549）抑制率可达62.65%和54.82%。      

4-(3-(4-羟基苯基) -3-氧代-1-芳基丙氨基)-N-(5-甲基异噁唑-3-基)苯磺酰胺的合成与抗糖尿病活性

由磺胺甲噁唑、对羟基苯乙酮和芳香醛反应直接合成了13个未见报道的β-氨基酮,反应选择性发生在羰基α位。产物结构通过¹H NMR、¹³C NMR、MS进行了表征。生物活性试验显示,低浓度范围,所得化合物不仅显示一定的蛋白质酪氨酸磷酸酶1B(PTP1B)和α-葡萄糖苷酶抑制活性,而且具有中等强度的过氧化物酶体增殖物激活受体反应元件(PPRE)的激动活性,8个化合物的激动活性超过40％,其中化合物11的活性达到72.7％。     

新型苯丙氨酸三肽衍生物的合成及其抗乙肝病毒活性

以具有抗HBV活性的苯丙氨酸二肽化合物马蹄金素(MTS)为先导化合物,设计并合成了23个新型的苯丙氨酸三肽衍生物（4a~4h, 5, 6a, 6b和8a~8k）,其结构经¹H NMR, ¹³C NMR和MS(ESI)表征。采用HepG2 2.2.15细胞为乙肝病毒载体,评价了目标化合物的抗HBV活性。结果表明：化合物5（IC₅₀=2.98 μM）、 6b（IC₅₀=0.62 μM）和8k（IC₅₀=5.07 μM）对HBV DNA复制的抑制活性优于MTS（IC₅₀=11.16 μM）。     

新型螺[二氢呋喃-2,3'-氧化吲哚]衍生物的合成及其对巨噬细胞RAW264.7的抑制作用

以20 mol%Et₃N作为催化剂,3-羟基氧化吲哚与β-芳基丙烯二腈为原料,经Michael加成/环化串联反应合成了13个新型螺[二氢呋喃-2,3′-氧化吲哚]衍生物(3a～3m),分离收率51%～99%, dr值1:1～4:1,产物结构经¹H NMR, ¹³C NMR和HR-MS(ESI-TOF)表征。考察了化合物对LPS激活巨噬细胞RAW264.7的抑制作用。结果表明：化合物3g的细胞抑制活性最强(IC₅₀: 18.59 μM),化合物3d对炎症因子NO释放的抑制活性最强(IC₅₀: 50.87 μM)。     

2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类化合物的合成、结构与体外抗癌活性

以天然产物没食子酸为原料经醚化、酯化、酰肼化、成盐、闭环、硫醚化六步反应合成了6个2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类衍生物, 釆用铟催化下水相合成目标化合物8, 具有反应条件温和, 合成收率高的特点; 用IR, ¹H NMR, ¹³C NMR和元素分析对各化合物进行了表征及结构确证, 并用X射线单晶衍射法测定了化合物8a [2-(2-氯-5-吡啶甲基)硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑]的晶体结构, 采用MTT法进行了新化合物抑制PC3和BGC-823癌细胞体外试验, 结果表明在5μmol•L^－1浓度下化合物8e对PC3的抑制活性为55.71%. 化合物8b对BGC-823细胞抑制活性为66.21%.     

铁(Ⅲ)催化氯代炔烃水化反应合成α-氯代甲基酮类化合物

研究了Fe(Ⅲ)催化氯代炔烃水化生成α-氯代甲基酮化合物的反应, 考察了催化剂的种类、 酸的种类、 反应温度以及溶剂对反应的影响.结果表明, 采用FeCl₃·6H₂O(摩尔分数5%)和甲基磺酸(摩尔分数20%), 在1,2-二氯乙烷溶剂中, 氯代炔烃于80 ℃进行水化反应3 h, 可以高产率得到α-氯代甲基酮产物. 所得化合物的结构采用IR, ¹H NMR, ¹³C NMR及MS等方法进行了表征. 该水化反应合成方法简单、 条件温和且收率良好, 为合成α-氯代甲基酮提供了一种简便途径.     

Liquid chromatographic/electrospray ionization mass spectrometric identification of the oxidation end-products of metformin in aqueous solutions

Metformin is an antihyperglycemic drug that exhibits some antioxidant properties. HO*-induced oxidation of metformin was studied in aqueous solution, in both aerated and deaerated conditions. Gamma radiolysis of water was used to generate HO* free radicals, capable of initiating one-electron oxidation of metformin. Oxidation end-products were identified by direct infusion mass spectrometry (MS) and high-performance liquid chromatography/mass spectrometry (HPLC/MSn): for every product, structure elucidation was based on its mass (simple mass spectra confirmed by HPLC/MS). In addition, fragmentation spectra (MS2, MS3 and MS4) and the determination of deuterium-hydrogen exchange sites provided valuable information allowing the complete identification of some of the end-products. At low radiation dose, four products were identified as primary ones, since they result from the direct attack of HO* radicals on metformin. These primary oxidation end-products were identified respectively as hydroperoxide of metformin, covalent dimer of metformin, methylbiguanide and 2-amino-4-imino-5-methyl-1,3,5-triazine. At high radiation dose, seven other products were identified as secondary ones, resulting from the HO*-induced oxidation of the primary end-products. A reaction scheme was postulated for the interpretation of the results.     

Several Rules for Treating Phenol Wastewater via Oxidation by O3/UV-formed Radicals

IntroductionA large amount of phenol wastewater comes fromdifferent sources with potential severe impact to life andenvironment.Phenol is a prototype poison,which istoxic to all living creatures.Phenol can coagulate pro-tein and devitalize cells,especiall…     

氯丙嗪用于面粉中过氧化苯甲酰的快速测定

在磷酸介质中,以盐酸氯丙嗪为光谱探针,分光光度法测定面粉中过氧化苯甲酰(BPO)。结果表明:室温下氯丙嗪-BPO体系在530nm波长处有最大吸收,表观摩尔吸光系数ε530=1.6×104L.mol-1.cm-1,BPO含量在1.0×10-4～4.0×10-3mg.mL-1范围内符合Beer定律。检出限为5.0×10-5mg.mL-1,加标回收率为96.5%～101%,RSD为1.8%～3.2%,该法简便易行,适用于测定面粉中微量BPO。     

电子受体H2O2和O2对TiO2光催化甘油氧化反应中活性氧物种1O2和OH?的影响

在室温条件下研究了电子受体H2O2和O2对TiO2光催化甘油氧化反应中的活性氧物种、甘油转化率和产物分布的影响。当在紫外光辐射和TiO2的体系中不存在电子受体时,只产生HO?自由基。而当在此体系中有电子受体存在时,则产生了HO?自由基和1O2,但它们的浓度不同,这取决于电子受体的浓度。以H2O2为电子受体时甘油转化率的提高大于以O2为电子受体时。甘油转化生成有价值产物的类型则与体系中的活性氧物种浓度有关。     

Effect of pH on lipid oxidation of red onion skin extracts treated with washed tilapia (Oreochromis niloticus) muscle model systems

The aim of the study was to investigate the effect of pH on the lipid oxidation of red onion skin extracts (ROSEs) treated with washed tilapia muscle model systems (WTMS). Minced and buffered washed samples were prepared at pH 6.3 and 6.8. The WTMS were treated with2 different concentrations of red onion skin prior to storage for 5 days. Lipid oxidation was investigated via peroxide values (PVs), thiobarbituric acid reactive substances (TBARS), and the formation of volatile compounds. Fatty acid profiles of the samples were also identified. The ROSEs were able to significantly suppress the PV (~71%) and TBARS (~42%) formation. Hexanal and octanal formations in the WTMS were relatively less in the ROSE-treated samples. The WTMS samples prepared at pH 6.3 were more vulnerable to lipid oxidation than those prepared at pH 6.8. Red onion skin polyphenols may increase the lag phase of lipid oxidation, depending on pH levels, resulting in the shelf life extension of raw fish.     

Probing hydroxyl radicals and their imaging in living cells by use of FAM-DNA-Au nanoparticles

The incorporation of gold nanoparticles (Au NPs) as quencher modules in fluorescent probes for DNA damage caused by intracellular hydroxyl radicals (HO*) is reported. Au NPs of 15 nm diameter were decorated with DNA oligomers terminating in thiol functions in their 3' positions and possessing 5' fluorophore modifications. The Au NPs, which have high extinction coefficients, functioned as excellent fluorescent quenchers in the fluorophore-Au NP composites. FRET is switched off as a factor of HO*-induced strand breakage in the single-stranded DNAs, restoring the fluorescence of the quenched fluorophores, which can be followed by spectrofluorimetry. In vitro assays with HO*-generating Fenton reagent demonstrated increases in fluorescence intensity with a linear range from 8.0 nM to 1.0 microM and a detection limit as low as 2.4 nM. Confocal microscopic imaging of macrophages and HepG2 revealed that the probe is cell-permeable and intracellular HO*-responsive. The unique combination of good selectivity and high sensitivity establishes the potential value of the probe for facilitating investigations of HO*-mediated cellular homeostasis and injury.     

Role of the somersault rearrangement in the oxidation step for flavin monooxygenases (FMO). A comparison between FMO and conventional xenobiotic oxidation with hydroperoxides

Model quantum mechanical calculations presented for C-4a-flavin hydroperoxide (FlHOOH) at the B3LYP/6-311+G(d,p) level suggest a new mechanism for flavoprotein monooxygenase (FMO) oxidation involving a concerted homolytic O-O bond cleavage in concert with hydroxyl radical transfer from the flavin hydroperoxide rather than an S(N)2-like displacement by the substrate on the C-4a-hydroperoxide OOH group. Homolytic O-O bond cleavage in a somersault-like rearrangement of hydroperoxide C-4a-flavinhydroperoxide (1) (FLHO-OH → FLHO···HO) produces an internally hydrogen-bonded HO(?) radical intermediate with a classical activation barrier of 27.0 kcal/mol. Model hydroperoxide 1 is used to describe the transition state for the key oxidation step in the paradigm aromatic hydroxylase, p-hydroxybenzoate hydroxylase (PHBH). A comparison of the electron distribution in the transition structures for the PHBH hydroxylation of p-hydroxybenzoic acid (ΔE(?) = 23.0 kcal/mol) with that of oxidation of trimethylamine (ΔE(?) = 22.3 kcal/mol) and dimethyl sulfide (ΔE? = 14.1 kcal/mol) also suggests a mechanism involving a somersault mechanism in concert with transfer of an HO(?) radical to the nucleophilic heteroatom center with a hydrogen transfer back to the FLH-O residue after the barrier is crossed to produce the final product, FLH-OH. In each case the hydroxylation barrier was less than that of the O-O rearrangement barrier in the absence of a substrate supporting an overall concerted process. All three transition structures bear a resemblance to the TS for the comparable hydroxylation of isobutane (ΔE(?) = 29.2 kcal/mol) and for simple Fenton oxidation by aqueous iron(III) hydroperoxides. To our surprise the oxidation of N- and S-nucleophiles with conventional oxidants such as alkyl hydroperoxides and peracids also proceeds by HO(?) radical transfer in a manner quite similar to that for tricyclic hydroperoxide 1. Stabilization of the developing oxyradical produced by somersault rearrangement for concerted enzymatic oxidation with tricyclic hydroperoxide 1 results in a reduced overall activation barrier.     

Rate constants for hydrogen abstraction reactions by the hydroperoxyl radical from methanol, ethenol, acetaldehyde, toluene, and phenol

An important step in the initial oxidation of hydrocarbons at low to intermediate temperatures is the abstraction of H by hydroperoxyl radical (HO(2)). In this study, we calculate energy profiles for the sequence: reactant + HO(2) → [complex of reactants] → transition state → [complex of products] → product + H(2)O(2) for methanol, ethenol (i.e., C(2)H(3)OH), acetaldehyde, toluene, and phenol. Rate constants are provided in the simple Arrhenius form. Reasonable agreement was obtained with the limited literature data available for acetaldehyde and toluene. Addition of HO(2) to the various distinct sites in phenol is investigated. Direct abstraction of the hydroxyl H was found to dominate over HO(2) addition to the ring. The results presented herein should be useful in modeling the lower temperature oxidation of the five compounds considered, especially at low temperature where the HO(2) is expected to exist at reactive levels.     

氧氟沙星在乙炔黑修饰电极上的电化学行为及测定

本文制备了一种乙炔黑修饰电极,研究了氧氟沙星(OFL)在该修饰电极上的循环伏安行为。结果表明,在pH=5的PBS缓冲液中,氧氟沙星在该修饰电极上出现一不可逆的氧化峰,在40～360 mV/s扫速范围内,氧化峰电流与扫速呈线性关系,表明该电极过程受吸附控制。计算了电极过程的部分动力学参数:反应电子数为2,电极有效面积为0.067 cm2。讨论了修饰剂用量、缓冲液种类、溶液pH值对测定的影响。用方波溶出伏安法对OFL进行测定,在2.5×10-6～2.5×10-4mol.L-1的浓度范围内与氧化峰电流(Ipa)呈线性关系,Ipa(μA)=-1.6148+0.2169c(10-6 mol.L-1),相关系数为0.9951,检出限为1.332×10-7 mol.L-1,回收率为90.40%～101.06%。     

A mixed valence manganese triangle in a trigonal lattice: structure and magnetism

The synthesis, structural and magnetic characterisation of trinuclear manganese cluster, [Mn(3)O(O(2)C-anth)(6)(HOCH(3))(3)] 1 (where O(2)C-anth = 9-anthracenecarboxylate), with crystallographic three-fold (C(3)) symmetry, are described. The cluster was prepared by a carboxylate exchange reaction between HO(2)C-anth and [Mn(12)O(12)(O(2)CMe)(16)(H(2)O)(4)] with concomitant fragmentation of the dodecanuclear Mn core of the starting material to form a trinuclear Mn(3)(μ(3)-O) cluster capped by six carboxylate ligands. Bond valence sum calculations and SQUID magnetometric measurements establish the oxidation states of the metal ions as Mn(II)·2 Mn(III) which are antiferromagnetically coupled.