Structure elucidation of a new isoflavone by exclusive use of ¹H NMR measurements
Copyright © 2015 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 53(2015), 10 vom: 02. Okt., Seite 860-5 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Letter Research Support, Non-U.S. Gov't Isoflavones Hydrogen 7YNJ3PO35Z |
| Zusammenfassung: | Copyright © 2015 John Wiley & Sons, Ltd. The leaves of Piscidia carthagenensis provided new 7,2',5'-trimethoxy-3',4'-methylenedioxyisoflavone (1), admixed with known 6,7-dimethoxy-3',4'-methylenedioxyisoflavone (2), and 5,4'-dihydroxy-7,2',5'-trimethoxyisoflavone (3), which were separated by extensive fractional solubillization. Selective irradiation of the H-5 "singlet" of 2 allowed distinction of the two methoxy group signals, whose chemical shift difference is only 0.004 ppm (1.2 Hz at 300 MHz). The (1)H and (13)C NMR data of 3 were assigned with the aid of HETCOR and gHMBC measurements. Although 1 looked inhomogeneous in the solid state, its solution structure followed from (1)H NMR measurements, where it looked homogeneous. To clarify the solid state aspect and confirm the structure of 1, two types of crystals were mechanically separated and subjected to single crystal X-ray diffraction measurements. This study revealed polymorphism because of the concomitant presence of orthorhombic and triclinic crystals, but showed no atropisomerism. The structure of 3 was also verified by X-ray diffraction crystallography |
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| Beschreibung: | Date Completed 15.04.2016 Date Revised 19.09.2015 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.4278 |