Converting the molecular framework of medicinal plant constituents: a fermented Mercurialis extract with wound-healing activity

Aqueous fermentation of medicinal plants represents an interesting option to obtain microbiologically stable extracts. Fermented extracts from dog's mercury (M. perennis L.) have recently shown immunomodulating activity on the expression of cytokines like IL-1β, TNF-α, IL-8 and PGE-2 in vitro, results which may explain the woundhealing effect of Mercurialis remedies [1]. In the current study, a closer investigation on the conversion of plant constituents during the production of a fermented extract from M. perennis was performed. Profiling of dichloromethane extracts showed three novel alkaloid metabolites 2, 3, 4 which were fully characterized by GC/MS, NMR as well as by total synthesis. These compounds may be formed by scission of the molecular framework of the dimeric alkaloid structure 1, genuinely found in the fresh M. perennis extract. Furthermore, the biotransformation of the depsides phaselic and mercurialis acids were studied in the aqueous extract. Both constituents showed a second order degradation kinetics as monitored by HPLC. Several novel formed constituents like dihydrocinnamic acids, ethyl phenols and 2-hydroxy acids were also detected, the latter presumably representing degradation products from depsides and amino acids [2]. The results obtained may help to understand the complex chemistry proceeding during the fermentation of a medicinal plant extract.

References:

[1] P. Lorenz, C. Beckmann, J. Felenda, U. Meyer, F. C. Stintzing, Z. Phytother. 34: (2013).

[2] P. Lorenz, J. Conrad, F. C. Stintzing, Chem. Biodivers., DOI 10.1002/cbdv.201200424.