Nitrosonium(NO^+) catalyzed Michael addition of indoles to unsaturated enones

An efficient Michael addition of indoles to unsaturated enones, such as chalcones and β-nitrostyrenes, was achieved in the presence of a catalytic amount of nitrosonium tetrafluoroborate in ethyl ether. 2007 Long Min Wu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Reactivity of Indoles through the Eyes of a Charge-Transfer Partitioning Analysis

A global and local charge transfer partitioning model,based on the cornerstone theory developed by Robert G.Parr and Robert G.Pearson,which introduces two charge transfer channels(one for accepting electrons(electrophilic) and another for donating(nucleophilic)),is applied to the reaction of a set of indoles with 4,6-dinitrobenzofuroxan.The global analysis indicates that the prevalent electron transfer mechanism in the reaction is a nucleophilic one on the indoles,i.e.,the indoles under consideration transfer electrons to 4,6-dinitrobenzofuroxan.Evaluating the reactivity descriptorswith exchange-correlation functionals including exact exchange(global hybrids) yields slightly better correlations than those obtained with generalized gradient-approximated functionals;however,the trends are preserved.Comparing the trend obtained with the number of electrons donated by the indoles,and predicted by the partitioning model,with that observed experimentally based on the measured rate constants,we propose that the number of electrons transferred through this channel can be used as a nucleophilicity scale to order the reactivity of indoles towards 4,6-dinitrobenzofuroxan.This approach to obtain reactivity scales has the advantage of depending on the intrinsic properties of the two reacting species;therefore,it opens the possibility that the same group of molecules may show different reactivity trends depending on the species with which they are reacting.The local model allows systematic incorporation of the reactive atoms based on the their decreasing condensed Fukui functions,and the correlations obtained by increasing the number of reactive atoms participating in the local analysis of the transferred nucleophilic charge improve,reaching an optimal correlation,which in the present case indicates keeping three atoms from the indoles and two from 4,6-dinitrobenzofuroxan.The atoms selected by this procedure provide valuable information about the local reactivity of the indoles.We further show that this information about the most reactive atoms on each reactant,combined with the spatial distribution of the nucleophilic and electrophilic Fukui functions of both reactants,allows one to propose non-trivial candidates of starting geometries for the search of the transition state structures present in these reactions.

Design,synthesis and antiproliferative activities of novel 5H-pyridazino[4,5-b]indoles

A novel series of 5H-pyridazino[4,5-b]indoles were designed and synthesized in order to find novel potent anticancer compounds. The structures were confirmed by ^1H NMR and MS. Their antiproliferative activities against two cancer cell lines were tested by the MTT method in vitro. Three of compounds （1e, 1g, and 1h） exhibited potent antiproliferative activities, especially compound lh （with IC50 values of 5.2 μmol/L and 1.9 μmol/L against Bel-7402 and HT-1080, respectively）. The preliminary structure-activity relationships of 5H-pyridazino[4,5-b]indole derivatives were discussed.

New Greener Alternative for Biocondensation of Aldehydes and Indoles Using Lemon Juice: Formation of Bis-, Tris-, and Tetraindoles

This work presents a new greener alternative for biocondensation of aldehydes and indoles for the synthesis of bis- and tris(indolyl)methanes catalyzed by lemon juice (Citrus limon) in good yields under ultrasound irradiation in aqueous ethanol. Various substituted aldehydes with indoles under this reaction condition are elucidated. Also, tetraindolyl compounds were prepared using terephthaldialdehyde by following the same protocol. This method is an environmentally benign, efficient reaction, which requires shorter reaction time and simple experimental and work-up procedures.

Synthesis and preliminary cytotoxic evaluation of substituted indoles as potential anticancer agents

A variety of indole derivatives were designed, synthesized and preliminarily evaluated for their in vitro cytotoxic activity in the A431 and H460 cell lines. All the compounds examined conferred unusual potency in a tumor cell cytotoxicity assay. The findings showed the indole derivatives would be a promising candidate for the development of new anticancer agents.

Soluble Polymer-supported Synthesis of Indoles via Palladium-mediat-ed Heteroannulation of Terminal Alkynes with o-Iodoanilines

A soluble polymer-supported synthesis of indoles via palladium-mediated hetero- annulation of terminal alkynes with o-iodoanilines has been described. The protocol provides a useful tool for constructing combinatorial indole libraries.

Analogs of Antifungal Indoles Isolated from Aporpium Caryae with Activity Against Sudden-Death Syndrome of Soybean

Based on the precedent discovery of a weak antifungal indole isolated from Aporpium caryae, which increased its activity when changing the N-alkyl chain, nineteen N-alkyl indoles, with alkyl chains from one to ten carbons and one or two hydroxyls, one amine or bromine functional groups, were prepared and fully characterized by spectroscopic methods. The aim of this study is the search for new synthetic agrochemical leads derived from natural products. The antifungal activity of the synthesized compounds against three fungal strains was measured in vitro. Six compounds presented good activity against Fusarium virguliforme, the causal agent of sudden-death syndrome (SDS) in soybean, in a bioautography assay. Four of them were tested in a germination test and in a greenhouse experiment. All tested compounds, applied as seed treatment, showed antifungal properties being effective to control SDS when there was low level of fungal contamination. Results indicate that some of the tested compounds are acting as growth inhibitors and represent new leads for the treatment of SDS for which no specific treatment has been previously reported.

Chemical Basis for the Phytotoxicity of Indoles in Relation to the Allelopathy of Cereals

Phytotoxic activity of an indole series substituted with electron-acceptor and electron-donor groups in the aromatic ring was determined. They are potential decomposition products, of natural indole alkaloids in cereals plants with allelopathic properties. Phytotoxic selectivity was evaluated from antialgal activity against the microalga Chlorella vulgaris, seed germination seeds and biomass weight of seedling of barley, rye, wheat, oat and maize species and the weed Lolium rigidum. Lipophilia character of the compounds was determined by RP-HPLC method. Both, the electronic character of the substituents, evaluated from σp parameter, and the lipophilia character of the molecules measured from logPHPLC parameter, are involved in the phytotoxic activity. The three bio indicators has shown that the compounds with the higher electron-acceptor groups showed the higher level of phytotoxicity and the molecules with electron-donor groups showed the lowest activity, although, in some cases, this behavior is modified by the lipophilic properties of the molecules. These results are rationalized in terms of polarization of N-H bond of heterocyclic ring. Compounds with the higher logPHPLC values showed the higher phytotoxic activity. Further evidence on the role of lipophilicity was obtained from linear regression between the average inhibitions percentages of biomass and logPHPLC values. The activity increased linearly by increasing the lipophilic character of the compounds. Therefore, quantitative effects in the phytotoxic activity of the electronic properties of the substituents in the aromatic ring and lipophilic character of the indoles can be inferred from σp and logPHPLC parameters, respectively. The results strongly suggest that the potential decomposition products of the natural indole alkaloids from cereals or other natural sources may be in connection with the allelopathic phenomenon of plants when are released into the soil.

Conjugate Addition of Indoles to <i>α,β</i>-Unsaturated Ketones Using Bismuth (III) Bromide

An efficient method for the conjugate addition of indoles to a variety of chalcones using BiBr3 in ethanol (190 proof) is reported. Products are isolated by a simple procedure that avoids an aqueous work up and extensive chromatography, thus minimizing waste. Bismuth (III) compounds are especially attractive from a green chemistry perspective because they are remarkably nontoxic, non-corrosive and relatively inexpensive.

Catalyst and Solvent-Free Microwave Assisted Expeditious Synthesis of 3-Indolyl-3-hydroxy Oxindoles and Unsymmetrical 3,3-Di(indolyl)indolin-2-ones

A simple and efficient method for the synthesis of 3-indolyl-3-hydroxy oxindoles and unsymmetrical 3,3-di(indolyl)indolin-2-ones using microwave irradiation without catalyst and solvent is described. A series of 3-indolyl-3-hydroxy oxindoles and unsymmetrical 3,3-di(indolyl)indolin-2-ones have been synthesized in very short reaction times of 5 and 10 minutes and in yields ranging from 31% to 98% and from 53% to 78% respectively. This method offers a significant advantage over the conventional methods in terms of simplicity and shorter reaction time. To the best of our knowledge compounds N-allyl-3-hydroxy-3-(1-methyl-indol-3-yl)indolin-2-one (6c), N-allyl-3-hydroxy-3-(5-methoxy-indol-3-yl)indolin-2-one (8c), N-benzyl-3-hydroxy-3-(1-methyl-indol-3-yl) indolin-2-one (10c), N-propargyl-3-hydroxy-3-(1-methyl-indol-3-yl)indolin-2-one (13c), N-propargyl-3-hydroxy-3-(5-methoxy-indol-3-yl)indolin-2-one (14c), 3-(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (1e), 3-1-methyl(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (2e), 3-1-allyl(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (3e), 3-1-benzyl(5-methoxy-1H-in- dol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (4e) and 3-1-(prop-2-ynyl)(5-methoxy-1H-indol-3-yl)-3(1H-indol-3-yl)indolin-2-one (5e) are reported here for the first time. All the compounds are characterized by IR, 1H, 13C NMR and HRMS.

TsOH·H₂O-Catalyzed Friedel-Crafts of Indoles of 3-Hydroxyisobenzofuran-1(3<i>H</i>)-One with Indoles: Highly Synthesis of 3-Indolyl-Substituted Phthalides

An efficient and facile method for the synthesis of 3-indolyl-substituted phthalides by Friedel-Crafts alkylation of indoles with 3-hydroxyisobenzofuran-1(3H)-one has been developed. Using only 2 mol-% TsOH·H2O as the catalyst, various substituted indoles can react smoothly at room temperature to give the corresponding phthalides products in good to excellent yields (up to 96%).

Discovery of prenylated indole alkaloid and natural xanthone from cold-seep sediment derived fungus Talaromyces funiculosus SD-523

A new prenylated indole alkaloid 11,17-epi-mangrovamide A(1),a new natural occurring product,1,7-dihydroxy-6-methyl-8-hydroxymethyl-xanthone(2),two known alkaloids,mangrovamide A(3)and mangrovamide G(4),and four known polyketide derivatives(5–8)were isolated and identified from the cold-seep sediment derived fungal strain Talaromyces funiculosus SD-523.Their structures were elucidated by combination of nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),quantum chemical electronic circular dichroism(ECD),and DP4+probability analysis as well as by comparison of the data with literature reports.All isolated compounds were tested for antibacterial activities.

Two new bromoindoles from red alga Laurencia similis

Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods （including 1D and 2D NMR technique）, their structures have been elucidated as 2,2＇,5,5＇,6,6＇- sixibromo-3, 3＇-bi-lH-indole and 3, 5-dibromo-1-methylindole, respectively.

植物生长调节剂对‘小米’红花油茶苗木生长的影响

为探究植物生长调节剂对‘小米’红花油茶苗木生长的作用以及最佳施用量,采用赤霉素(GA3)和吲哚乙酸(IAA)二因素三水平3×3回归设计,选择不同浓度的GA3、IAA及其组合处理云南高山区‘小米’红花油茶嫁接苗,所得数据经过协方差排除初始值影响后进行方差分析和多重比较。结果显示:(1)9种不同组合中,对苗高有极显著促进效果的最佳浓度组合是5 mg/L GA3和5 mg/L IAA,其处理比对照高出34.4%。(2)对地径有极显著促进效果的浓度组合是10 mg/L GA3+5 mg/L IAA,比对照高出24.6%。(3)9种组合中,所有处理对冠幅都有极显著促进效果,其中最佳浓度组合是0 mg/L GA3+5 mg/L IAA组合,比对照高出26.1%。研究结果表明:采用GA3的浓度为10 mg/L,IAA的浓度为0 mg/L或者5 mg/L的植物生长调节剂组合对‘小米’红花油茶嫁接苗进行喷施,可以明显促进其苗高、地径及冠幅的综合增长。

晋西北酸粥源短乳杆菌(Levilactobacillus brevis)M-10安全性评估

从晋西北酸粥发酵液中分离到一株短乳杆菌M-10,发现其具有耐酸、耐胆盐、抗氧化、抗菌、降胆固醇等多种益生特性。为了更好地应用该菌株,该研究评价了其体外和体内的安全性,包括溶血活性检测、明胶液化能力测定、硝基还原酶活性测定、吲哚和生物胺生成能力测定、SD大鼠急性毒性和亚急性毒性实验。经检测发现,短乳杆菌M-10缺乏溶血活性,不能液化明胶,缺乏硝基还原酶活性,不会生成吲哚,不能产生生物胺,包括酪胺、组胺、尸胺、腐胺等;该菌对SD大鼠的一般体征和血常规指标均无明显不良影响。以上研究结果表明,短乳杆菌M-10具有很好的安全性。该研究可为后续短乳杆菌M-10作为发酵剂或益生菌的开发奠定基础。

尿液中蛋白结合毒素水平与上尿路结石的相关性研究

目的·探讨尿液中蛋白结合毒素(protein-bound uremic toxin,PBUT)水平与上尿路结石形成的关系。方法·以海南省儋州市海头镇社区18~80岁居民为研究对象。记录研究对象基本信息和近3 d饮食情况,收集空腹血清和24 h尿液标本,所有对象接受肾脏和输尿管B超检查。将B超检查发现有上尿路结石或有明确上尿路结石病史的对象作为结石组,其他作为非结石组。检测血、尿中结石形成相关的生化指标,通过高效液相色谱检测血、尿中的PBUT(硫酸吲哚酚、3-吲哚乙酸和硫酸对甲酚),以及尿草酸和尿枸橼酸水平。通过多因素Logistic回归分析上尿路结石形成的相关因素。采用Spearman相关性检验分析尿PBUT与尿尿酸、草酸和枸橼酸的相关性。结果·经筛选,共纳入117例研究对象,其中结石组54例,非结石组63例。2组的性别、年龄、血清指标,以及高血压、糖尿病、高尿酸血症/痛风等合并症比例方面差异均无统计学意义。结石组的24 h尿液pH值、钙、尿酸和氯均显著高于非结石组(均P<0.05),而硫酸吲哚酚显著低于非结石组(P<0.05)。多因素Logistic回归分析结果显示,除尿钙外,尿硫酸吲哚酚水平(OR=0.929,95%CI 0.875~0.986,P=0.016)也是上尿路结石形成的独立相关因素。Spearman相关性分析结果显示,24 h尿液中3-吲哚乙酸(r=0.420,P=0.000)和硫酸对甲酚(r=0.307,P=0.001)水平均与草酸呈正相关,硫酸对甲酚水平与尿酸呈正相关(r=0.297,P=0.002),硫酸吲哚酚水平与枸橼酸呈正相关(r=0.289,P=0.002)。结论·在该研究人群中,尿硫酸吲哚酚水平降低可能是上尿路结石形成的独立危险因素,且尿液中PBUT水平与尿酸、草酸、枸橼酸的水平相关。

阳离子-π动态交联高性能聚芳吲哚醚酮的构筑

玻璃化转变温度(Tg)和热稳定性是聚合物重要的物理性能,影响了材料的应用领域。交联被认为是提高Tg和热稳定性的重要方法之一。本文以4,4-二氟二苯酮和4-羟基吲哚为单体,通过亲核取代反应成功制备了线型聚芳吲哚醚酮(PINEK),并通过简易的浸泡碱性水溶液的方式实现了PINEK的阳离子-π动态交联。与传统的线型聚醚醚酮(PEEK)和PINEK相比,交联型聚芳吲哚醚酮(C-PINEK)表现出较高的Tg(Tg=251℃)和优异的热分解温度(Td=501℃)。

钯催化N-磺酰基吲哚衍生物碳氢键芳基化反应

以碘代芳烃为芳基化试剂,探讨了N-对甲苯磺酰基吲哚通过磺酰基团导向的钯催化C—H键选择性芳基化反应过程。结果表明,以醋酸钯为催化剂、三苯基膦为配体、碳酸钠为碱、碳酸银为添加剂的条件下,N-对甲苯磺酰基吲哚在1,4-二氧六环溶剂中于120℃下反应24 h可获得2位和2,7位芳基化的产物,反应总产率可达93%。在该条件下,通过改变底物和碘代芳烃的结构测试了该法的适用范围与局限性,共制备得到28种芳基化吲哚衍生物,总产率为22%~93%,产物经~1HNMR、^(13)CNMR和HRMS表征确定了其化学结构。

外源IBA对无花果扦插苗抗氧化特性及IAA生物合成途径的影响

【目的】探讨适宜浓度吲哚丁酸(IBA)对无花果插穗生根萌芽、抗氧化性及生长素生物合成途径相关基因表达的影响,为其应用于无花果的育种、繁殖、推广和种植提供理论依据。【方法】以‘波姬红’无花果品种硬枝为插穗,观测不同质量浓度IBA(0,30,45,60,90 mg/L)处理下插穗生根性状、抗氧化特性,并对45 mg/L IBA处理及对照组的扦插枝条中段的腋芽进行转录组分析。【结果】(1)无花果插穗萌芽率和生根率在45 mg/L IBA处理时达到最大值,并与其他处理和对照差异显著。(2)随IBA浓度增加,插穗SOD和CAT活性先下降后上升,并均在45,60 mg/L IBA处理下显著低于对照,而POD活性无显著变化;各浓度IBA处理插穗中MDA和H2O2含量均显著高于对照,且45 mg/L IBA处理MDA显著低于其余处理。(3)45 mg/L IBA处理及对照组中共存在6 879个差异表达基因,KEGG富集显示有10个差异途径,GO富集分析表明生物学过程和分子功能为主要的生物学途径;与CAT、SOD相关的基因集中富集在过氧化物酶体通路上,POD相关基因则富集在苯丙烷生物合成通路中;IAA生物合成途径中代谢相关基因FcGH3显著上调表达,与信号转导相关基因FcAUX1、FcARG7和FcARF等显著下调表达。【结论】外源IBA处理会导致无花果插穗抗氧化酶和IAA生物合成途径中相关基因表达的差异变化,增强插穗抗逆性,促进插穗生根、萌芽、成苗,并以外源45 mg/L IBA促进效果最好。