Revision of the structure of escholidine.
The structure of the quaternary tetrahydroprotoberberine alkaloid escholidine is revised on the basis of 2D NMR spectroscopy and X-ray diffraction. In contrast to the originally reported constitution, escholidine bears an -OH group at C-9 and an -OCH3 group at C-10. The 1H and 13C NMR data and long-range 1H-13C and NOE interactions of escholidine are compared with those of thalifendine and tetrahydroberberrubine. The 15N NMR data of escholidine obtained by using long-range 1H-15N correlation experiments at natural abundance are also reported.
Chudík
Stanislav
S
Department of Natural Drugs, Pharmaceutical Faculty, University of Veterinary and Pharmaceutical Sciences, Palackého 1-3, CZ-612 42 Brno, Czech Republic.
Marek
Radek
R
Seckárová
Pavlína
P
Necas
Marek
M
Dostál
Jirí
J
Slavík
Jirí
J
D001600:Berberine Alkaloids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004149:Dioxoles / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular
D001600:Berberine Alkaloids; D004149:Dioxoles; C510124:escholtzine