01984naa a2200253 a 450000100080000000500110000800800410001902400380006010000140009824501200011226000090023250005820024152006270082365000210145065300310147165300140150265300250151670000170154170000200155870000170157870000140159570000180160977301030162710539052020-06-02       2015    bl uuuu     u00u1 u    #d7 a10.1016/j.phytol.2015.10.0222DOI1 aREINA, L.  aIsolation and structural characterization of new piperidine alkaloids from Prosopis affinis.h[electronic resource]  c2015  aArticle history: Received 30 July 2015; Received in revised form 16 October 2015; Accepted 27 October 2015. Acknowledgments: Funding from the Instituto Nacional de Investigación Agropecuaria (award L4-FO-21-0-00), the Agencia Nacional de Investigación e Inovación (award POS_NAC_2014_1_102226), the Programa 720 from the Dirección General de Relaciones y Cooperación (UdelaR), and the Programa de Desarrollo de la Ciencias Básicas is greatly acknowledged. We also wish to thank Rafael Gonzáles and Alejandra Rodriguez for their assistance with the HR-ESIMS measurements.  aThe isolation of three new N-methylated piperidine-3-ol alkaloids from the bark of Prosopis affinis Spreng. (Ñandubay) is described. Together with MS and IR data, results from 1D and 2D NMR experiments allowed for the identification of N-methyl-2-isocassine, N-;methyl-6-isocassine, and N-methyl-6- isocarnavaline. Inspection of 1D-NOESY spectra and coupling constant data revealed that the heterocyclic moiety of the alkaloids is in fast conformational equilibrium in solution, and this behavior had to be taken into account in order to determine the relative configuration of the chiral centers of the piperidine rings.  aPROSOPIS AFFINIS  aCONFORMATIONAL EQUILIBRIUM  aÑANDUBAY  aPIPERIDINE ALKALOIDS1 aBENNADJI, Z.1 aVINCIGUERRA, V.1 aFERREIRA, F.1 aMOYNA, G.1 aMENÉNDEZ, P.  tPhytochemistry Letters, 2015gv. 14, p. 265-269. https://doi.org/10.1016/jDOI: .phytol.2015.10.022