排序方式: 共有35条查询结果,搜索用时 62 毫秒
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Lipase from Mucor miehei (MML) has been selected as the most suitable enzyme to catalyze the efficient monobenzoylation of 1,4-diols using vinyl benzoate as acyl transfer reagent in tert-butyl methyl ether. The regioselectivity of the monobenzoylation of 2-substituted-1,4-diols has been studied as well. 相似文献
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Silvana Casati Ada Manzocchi Roberta Ottria Pierangela Ciuffreda 《Magnetic resonance in chemistry : MRC》2010,48(9):745-748
The complete 1H, 13C and 15N NMR signals assignments of some new isopentenyladenosine analogues were achieved using one‐ and two‐dimensional experiments (gs‐NOESY, gs‐HMQC and gs‐HMBC). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Roberta Ottria Silvana Casati Pierangela Ciuffreda 《Magnetic resonance in chemistry : MRC》2012,50(12):823-828
The complete 1H, 13C and 15N NMR signal assignments of some N‐ and O‐acylethanolamines, important family of naturally occurring bioactive lipid mediators, were achieved using one‐dimensional and two‐dimensional experiments (gs‐HMQC and gs‐HMBC). Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Sandra Gemma Gagan Kukreja Pierangela Tripaldi Maria Altarelli Matteo Bernetti Silvia Franceschini Luisa Savini Giuseppe Campiani Caterina Fattorusso 《Tetrahedron letters》2008,49(13):2074-2077
Nickel(II) chloride/sodium borohydride combination was employed for the reduction of 4-hydrazinoquinoline derivatives to the corresponding anilines. This reductive protocol was efficiently applied for the reductive cleavage of monosubstituted hydrazines. We described herein the microwave-assisted synthesis of 4-hydrazinoquinolines, which furnished a high yielding and rapid two-step procedure for the synthesis, under mild conditions, of 4-aminoquinolines as antimalarial precursors. 相似文献
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Cappiello A Famiglini G Mangani F Palma P 《Journal of the American Society for Mass Spectrometry》2002,13(3):265-273
A miniaturized, aerosol based interface for directly coupling a liquid chromatograph with a mass spectrometer is presented. The interface is entirely within the electron ionization (EI) source of the mass spectrometer and no additional, external devices are needed. This simple and effective approach exploits micro-flow nebulization technology providing a new interface suitable for a variety of applications of environmental and biological interest. The new interface provides necessary linearity, ruggedness, sensitivity, and reproducibility of response for trace level analysis, and readily interpretable mass spectra for unambiguous identification of unknown compounds of small to medium molecular weight. 相似文献
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Palma P Cappiello A De Simonii E Mangani F Trufelli H Decesari S Facchini MC Fuzzi S 《Annali di chimica》2004,94(12):911-919
A conspicuous fraction of the water soluble organic compounds (WSOC) in fog and fine aerosol samples is composed by monosaccharide anhydrides, such as levoglucosan and its stereoisomers, galactosan and mannosan. Levoglucosan is produced exclusively during wood combustion processes, making it a very useful tracer for plant combustion emissions in the atmosphere. This paper describes a new experimental approach, based on electrospray-tandem mass spectrometry (ESI-MS/MS), for the identification of levoglucosan in fog water samples. The analytical method proposed allows to identify the specific sugar anhydrides directly in the liquid phase without the need of any derivatization process. 相似文献
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Enzo Santaniello Silvana Casati Pierangela Ciuffreda Giuseppe Meroni Alessandro Pedretti Giulio Vistoli 《Tetrahedron: Asymmetry》2009,20(16):1833-1836
The Burkholderia cepacia lipase-catalyzed transesterification of 2-methyl-3-phenyl-1-propanol with vinyl esters proceeds with high enantioselectivity independently of the acyl chain length and the low enantioselectivity of the same reaction with 2-phenyl-1-propanol is not affected by chain length of the vinyl esters. A molecular modelling approach has been developed in order to rationalize the enzymatic results. 相似文献
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A method to extract and analyze organic compounds from water is presented. A solid phase micro-trap (micro-SPE) directly connected to the micro-analytical column is used. Sensibility and specificity needed for trace analysis are guaranteed by mass spectrometric electron ionization (EI) detection. A new micro-HPLC/EI-MS interface called Capillary-EI (Cap-EI) is described. The ultimate evolution of this interface is also presented: in this extremely simplified interface the analytes are nebulized, vaporized and ionized in the small volume of the ion source. This interface, called Direct-EI, exploits nano- and micro-HPLC columns with a mobile phase flow rates ranging from 0.3 to 1.5 microL/min. Contemporary use of micro SPE, Cap-EI or Direct-EI gives us a powerful technique to identify and quantify organic pollutants at part per billion level (ppb). 相似文献