Qualitative and quantitative analysis of Potentilla fulgens roots by NMR, matrix-assisted laser desorption/ionisation with time-of-flight MS, electrospray ionisation MS/MS and HPLC/UV.

Introduction: Potentilla fulgens is a commonly used folk medicine by natives of northeast India, Nepal and Bhutan and is rich in polyphenolic and triterpene constituents.

Objective: To identify chemomarkers in the roots of P. fulgens by an interplay of (13)C-NMR, matrix-assisted laser desorption/ionisation with time-of-flight (MALDI/TOF) MS, electrospray ionisation (ESI) MS/MS and HPLC/UV.

Material And Methods: The (13)C-NMR spectrum of crude methanolic extract was recorded in deuterated dimethyl sulphoxide. For MALDI/TOF/MS analysis, 2,5-dihydroxybenzoic acid was used as the matrix. For determination of chemical constituents, two independent simple isocratic HPLC/UV methods for monomeric/oligomeric flavanols and triterpene acids were developed and validated.

Results: The (13)C-NMR spectrum of the methanolic extract indicated the presence of B-type oligomeric polyphenolics containing mainly epicatechin/catechin (epicat/cat) and epiafzelechin/afzelechin (epiafz/afz) as the monomeric units. Several isobaric monomeric and oligomeric flavanols and triterpenoids were tentatively identified by MALDI/TOF/MS and ESI/MS/MS. Fourteen compounds (four monomeric and five dimeric flavanols and five triterpene acids) were isolated using repeated column chromatography and semi-preparative HPLC, and were quantitated using HPLC/UV.

Conclusion: It is evident from these analyses that roots of P. fulgens contain flavans, including oligomeric flavanols, as major constituents followed by triterpene acids. The methods described can be applied to other Potentilla species to identify their constituents.