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Updated: Aug 7, 2026

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Revision of the structure of escholidine
Stanislav Chudík1, Radek Marek, Pavlína Seckárová
1Department of Natural Drugs, Pharmaceutical Faculty, University of Veterinary and Pharmaceutical Sciences, Palackého 1-3, CZ-612 42 Brno, Czech Republic.
Abstract:
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.
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