Effect-directed profiling of aqueous, fermented plant preparations via high-performance thin-layer chromatography combined with in situ assays and high-resolution mass spectrometry

Abstract

Aqueous, fermented preparations from a vast range of medical plants are among the active pharmaceutical ingredients of homoeopathic medicinal products. In this study aqueous, fermented plant preparations from Chamomilla recutita L. (C.r.), Allium cepa L. (A.c.), Equisetum arvense L. (E.a.) and Hamamelis virginiana L. (H.v.) of different years of harvest were screened using a generic high-performance thin-layer chromatography (HPTLC) method hyphenated to effect-directed analysis (EDA) and high-resolution mass spectrometry (HRMS). Using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), Gram-positive Bacillus subtilis and α-/β-glucosidase assays, followed by recording of elution head-based HPTLC-ESI-HRMS spectra, a fast assignment of multi-potent compounds was possible. This was exemplified for herniarin identified in C.r. and gallic acid in H.v. preparations. Strong radical scavenging and β-glucosidase inhibiting effects were observed for E.a. and H.v. preparations, whereas the most pronounced antibiotic activity against Gram-positive bacteria was found in C.r. and E.a. preparations. Besides the successful screening for radical-scavenging, antibiotic and anti-diabetic components, HPTLC-UV/Vis/FLD-EDA-HRMS provided profound information on aqueous, fermented plant preparations. Batch-to-batch variations of the plant preparations were not necessarily obvious from their HPTLC chromatograms, but could be substantiated based on their respective (bio)autograms. It became clear that effect-directed fingerprints allow the visualization and control of the fermentation processes in a meaningful sense.