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Z. Naturforsch. 2012,
67b, 411 – 416
doi:10.5560/ZNB.2012-0030
Isolation of the Pyrrolizidine Alkaloid Intermedine-N-oxide from Cerinthe glabra and ab initio Calculation of its 13C NMR Shifts
1 Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians University of Munich, Butenandtstr. 5–13, 81377 Munich, Germany
2 Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
Reprint requests to Prof. Dr. Franz Bracher. Fax: +49-89-218077802. E-mail:
Franz.Bracher@cup.uni-muenchen.de
Received January 28, 2012 / published online May 31, 2012
The pyrrolizidine alkaloid intermedine-N-oxide was isolated from Cerinthe glabra for the first time. Due to the questionable assignments of NMR signals of this compound in previous literature reports ab initio calculations of the 13C NMR values based on the GIAO approach, using HF and B3LYP levels of theory and the four basis sets 6-31G(d), 6-311G(d), 6-31G(d,p), and 6-311G(d,p) were performed. The assignments obtained this way are in very good accordance with the experimental values.
Key words: Intermedine-N-oxide, Cerinthe glabra, Pyrrolizidine Alkaloids, NMR Data, ab initio Calculations
Supporting Material: