Schmidt Andreas, Mordhorst Thorsten, Nieger Martin
Clausthal University of Technology, Institute of Organic Chemistry, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld, Germany.
Nat Prod Res. 2005 Jul;19(5):541-6. doi: 10.1080/14786410500034949.
Spectroscopic investigations reveal that a hydroquinone pyridinium alkaloid isolated from the leaves of pomegranates Punica granatum L. (X-ray) exists as a mixture of a conjugated and a cross-conjugated heterocyclic mesomeric betaine in aqueous and DMSO-d6 solution. Twofold deprotonation yields an anionic tripole.
