Lipophilic constituents from aerial and root parts of Mercurialis perennis L.

BACKGROUND

Dog's mercury (Mercurialis perennis L.) is a perennial herb used in remedies for medicinal purposes. The plant is supposed to contain potentially active substances but its constituents have only been rarely studied.

OBJECTIVE

Detailed studies on the phytochemical composition are of great interest to broaden the knowledge on the chemotaxonomy and pharmacognosy of M. perennis.

METHODS

Chloroform and hexane extracts from roots and aerial parts were investigated using GC/MS and LC/MS.

RESULTS

The whole plant exhihited a broad spectrum of structurally diverse constituents, mainly alkaloids, terpenes, sterols and simple aromatic compounds. Closer inspection of the piperidine alkaloid hermidin revealed its inherent instability towards air oxygen. To obtain quantitative data on these alkaloids the synthesis of the more stable reference compound 4-methoxy-1-methylpyridine-2,6(1H,3H)-dione (MMPD) was required. In this study, MMPD was detected for the first time as a genuine compound in Mercurialis. Hermidine quinone and hermidin dimers originating from hermidin via a free anionic radical reaction were also confirmed by GC/MS. Moreover, volatile compounds such as benzylalcohol, 2-phenylethanol, 4-methoxy- and 3,4-dimethoxyphenol, (-)-cis- and (+)-trans-myrtanol, (-)-cis-myrtanal as well as squalene were predominantely present in Mercurialis roots. In contrast, aerial parts mainly contained phytol derivatives, sterols and tocopherols. By changing solvent polarity, lipid and wax-containing fractions were obtained. LC/MS-studies on hexane extracts showed the presence of several mixed triglycerides constituted by linolenic, linoleic, oleic, stearic and palmitic acids, as well as lutein, carotenes and pheophytins.

CONCLUSIONS

The phytochemical data presented complement our knowledge on the rarely studied plant M. perennis and may broaden its use in future phytotherapy.