Chemistry of Hermidin: Insights from Extraction Experiments with the Main Alkaloid of Mercurialis perennis L. Tracked by GC/MS and LC/MS ⁿ.

Lorenz, Peter; Conrad, Jürgen; Duckstein, Sarina; Kammerer, Dietmar R.; Stintzing, Florian C.

Hermidin ( 1), a piperidine-2,3-dione alkaloid, has been previously detected as a lipophilic constituent in Mercurialis perennis L. and other Mercurialis species. Because of strong electron-withdrawing effects of its carbonyl groups, an acidic H-atom is easily subtracted from 1, whereas the latter shows high reactivity towards oxidation reactions or the attack of C-nucleophilic agents. To obtain a better understanding of possible chemical pathways upon extraction of root parts of M. perennis, the products obtained with different solvents from 1 were investigated. Extraction of M. perennis with aqueous MeOH or EtOH yielded a mixture of hermidin quinone ( 3), 5-hydroxy-4-methoxy-5-(alkoxycarbonyl)-1-methyl-3-pyrrolin-2-ones, 7 and 8, and d, l- and meso-isochrysohermidins, 5 and 6, all of them being investigated by GC/MS and LC/MS n. The latter compounds were supposedly formed by free-radical reactions, followed by spontaneous benzilic acid rearrangement and esterification. Furthermore, extraction of M. perennis with aqueous Me2CO produced an aldol condensation product, the known alkaloid speranskatine A ( 9a), which was identified by NMR after chromatographic purification. In a similar manner, a CH2 homolog of speranskatine A ( 10a) was obtained as a novel compound when ethyl methyl ketone (=butan-2-one; EtCOMe) instead of Me2CO was used for extraction. Consequently, 1 easily undergoes artefact formation upon extraction of plant material with polar or slightly polar solvents.

CHEMICAL research; EXTRACTION (Chemistry); ALKALOIDS; MICROBIAL metabolites; FOREST plants

Helvetica Chimica Acta, 2014, Vol 97, Issue 12, p1606

0018-019X

Academic Journal

10.1002/hlca.201400046