Structural Elucidation of an Atropisomeric Entcassiflavan-(4β→8)-Epicatechin Isolated from Dalbergia monetaria L.f. Based on NMR and ECD Calculations in Comparison to Experimental Data |
| |
| Authors: | Patrícia Homobono Brito de Moura Wolfgang Brandt Andrea Porzel Roberto Carlos Campos Martins Ivana Correa Ramos Leal Ludger A Wessjohann |
| |
| Institution: | 1.Natural Products Research Institute (IPPN), Center of Health Sciences, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil; (P.H.B.d.M.); (R.C.C.M.);2.Natural Products and Food Department, Pharmacy Faculty, Center of Health Sciences, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil;3.Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry (IPB), Weinberg 3, 06114 Halle, Germany; (W.B.); (A.P.) |
| |
| Abstract: | A rare dihydoxyflavan-epicatechin proanthocyanidin, entcassiflavan-(4β→8)-epicatechin, was isolated from Dalbergia monetaria, a plant widely used by traditional people from the Amazon to treat urinary tract infections. The constitution and relative configuration of the compound were elucidated by HR-MS and detailed 1D- and 2D-NMR measurements. By comparing the experimental electronic circular dichroism (ECD) spectrum with the calculated ECD spectra of all 16 possible isomers, the absolute configuration, the interflavan linkage, and the atropisomers could be determined. |
| |
| Keywords: | Dalbergia monetaria proanthocyanidin procassidin dimer electronic circular dichroism (ECD) quantum chemical calculation NMR |
|
|
