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81.
Cover Picture: Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem (Angew. Chem. Int. Ed. 19/2015)
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82.
Mass spectrometry detection of minor new meridianins from the antarctic colonial ascidians Aplidium falklandicum and Aplidium meridianum
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Laura Núñez‐Pons Rosa María Nieto Conxita Avila Carlos Jiménez Jaime Rodríguez 《Journal of mass spectrometry : JMS》2015,50(1):103-111
Taking into account the broad biological activities found in the meridianin indole alkaloids isolated to date, we have re‐examined the organic extracts of an Antarctic collection of the tunicates Aplidium meridianum and A. falklandicum (Chordata: Ascidiacea) by HPLC in conjunction with a high‐resolution mass spectrometer (HPLC‐MS). A new set of analogs of meridianins A–G has been detected, and their structures are proposed on the basis of the molecular formulae identified by LC‐HRMS analysis using a C18 column with a gradient of water/acetonitrile and an LTQ‐FT‐MS Orbitrap detector. Remarkably, dimers derived from meridianin A and from meridianin B or E were also detected. Our findings provide further evidence of the broad variability within the meridianin‐like derivatives of this highly bioactive alkaloid family. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
83.
Iodine‐Catalyzed Synthesis of Spiro[1,3,4‐benzotriazepine‐2,3′‐indole]‐2′,5(1H,1′H)‐diones under Mild Conditions
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The I2‐catalyzed preparation of spiro[1,3,4‐benzotriazepine‐2,3′‐indole]‐2′,5(1H,1′H)‐diones from 2‐aminobenzohydrazide and isatins in MeCN at room temperature in good‐to‐excellent yields is described. The structure of 3 was corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS data). A plausible mechanism for this type of reaction is proposed (Scheme 2). 相似文献
84.
Synthesis of a Benzannulated Pyrrolizidine by a Copper‐Catalyzed Intramolecular α‐Arylation Reaction
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Flavia Magalhaes Araujo Wellington Martins Ventura Jason Guy Taylor 《Helvetica chimica acta》2014,97(4):569-573
A synthetic route to the pyrrolo[1,2‐a]indole ring system (benzannulated pyrrolizidine) involving a base‐induced intramolecular aza‐Michael reaction as the key C? N bond‐forming penultimate step, followed by a Cu‐catalyzed intramolecular α‐arylation reaction, to provide the tricyclic framework over six steps is described. 相似文献
85.
86.
A.Vijender ReddyK. Ravinder T.Venkateshwar GoudP. Krishnaiah T.V. RajuY. Venkateswarlu 《Tetrahedron letters》2003,44(33):6257-6260
Reaction of indoles with electron deficient olefins under the influence of bismuth triflate has been studied at ambient temperature and affords the corresponding 3-alkylated indoles in excellent yields. 相似文献
87.
以β-萘胺为原料,经重氮化,还原,成环,N-烷基化,缩合5步反应得到目标化合物苯并吲哚三甲川花菁染料,并住部分中间体和目标化合物合成步骤中运用了微波辐射法合成技术.该类化合物通过红外光谱(IR)、核磁共振氢谱(^1H NMR)、紫外可见光谱(UV)进行了表征.结果表明,微波辐射法与传统方法相比,反应时间缩短7.4~47倍,产率提高了5.1%~50.4%. 相似文献
88.
Indole alkaloids from the African Strychnos species, their antiplasmodial and cytotoxic action, and structure -activity relationships are discussed in the review 相似文献
89.
90.
Two new monoterpenoid indole alkaloids, tabervarines A (1) and B (2), along with seven known monoterpenoid indole alkaloids, were isolated from the methanol extract of the twigs and leaves of Tabernaemontana divaricata. The structures including the absolute configurations of the new alkaloids were elucidated based on MS, NMR, and ECD calculation. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines were also evaluated. 相似文献