Conversion of hydrophilic constituents from Mercurialis perennis L. by lactic acid fermentation

Fermented and hydroalcoholic extracts from dog's mercury (Mercurialis perennis L.) are used in anti-inflammatory phytomedical remedies. In continuation of our research on lipophilic constituents [1], the hydrophilic compounds from M. perennis were studied by HPLC/DAD and GC/MS techniques. Following extraction with aqueous acidified extracts, solvent partitioning with ethylacetate and n-butanol yielded two fractions mainly containing glucaric-cinnamic acid derivatives 1 (EtOAc) as well as mono- and oligo-glycosides of kaempferol and quercetin (BuOH) all of which being assigned by LC/MS-MS. In the course of lactic acid fermentation phenolics were converted into smaller molecular units. Since the latter were hardly accessible by LC/MS, identification was performed by GC/MS after extraction with EtOAc and silylation: Dihydrocaffeic- (2, R=OH), dihydroferulic- (2, R=OCH3), dihydrocoumaric- (2 R=H) and 3-phenyllactic acids (3) as well as small volatile phenolics like 4-ethylcatechol (4, R=OH), 4-ethylphenol (4, R=H)) and several glycols were found. The present study marks the first comprehensive report on the hydrophilic compounds from M. perennis and their bioconversion upon fermentation.

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References: 1. Lorenz P., Hradecky M., Berger M., Bertrams J., Meyer U., Stintzing FC. (2009) Phytochem. Anal. 21:234–245.