A biochemometric approach for the identification of anti-inflammatory coumarines from Peucedanum ostruthium

Peucedanum ostruthium (L.) Koch has a longstanding history as herbal remedy in the Alpine region of Austria, where the rhizomes (= Radix Imperatoriae) are traditionally used to treat disorders of the gastro-intestinal and respiratory tract as well as the cardiovascular system [1]. A recent ethnopharmacological study on 71 Austrian traditional herbal drugs revealed a distinct anti-inflammatory activity by Radix Imperatoriae [2]. In the present work, the aim was to unravel the constituents responsible for the observed anti-inflammatory activity of a dichloromethane-methanol extract prior to isolation. Therefore, a recently developed biochemometric approach named ELINA (Eliciting Nature’s Activities) [3] was applied. Here, the objective was to simplify the crude extract by generating micro-fractions with quantitative variances of constituents over several consecutive fractions. This was achieved via an optimized high-performance counter-current chromatographic (HPCCC) fractionation. After this single fractionation step, ¹H-NMR data and bioactivity data from an in vitro assay on the cell adhesion molecules E-selectin and VCAM-1 were collected for all 31 micro-fractions. In parallel to a quantitative variance of ¹H-NMR signals over consecutive fractions, bioactivity patterns relating to this variation were obtained. To reveal chemical features crucial for the observed activities, statistical heterocovariance analyses (HetCA) [4] were performed. In addition, LC-MS-CAD data were used to facilitate the identification of the bioactive constituents. As a result, we identified two coumarins (Imperatorin and Ostruthol) and one chromone (Peucenin) responsible for the anti-inflammatory activities. The applied HetCA approach enables an early identification and dereplication of even minor bioactives prior to any isolation without wasting resources.

• References

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• 2 Vogl S, Picker P, Mihaly-Bison J, Fakhrudin N, Atanasov AG, Heiss EH. et al. Ethnopharmacological in vitro studies on Austria’s folk medicine - an unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs. J Ethnopharmacol 2013; 149: 750-771
• 3 Grienke U, Foster PA, Zwirchmayr J, Tahir A, Rollinger JM, Mikros E. 1H NMR-MS-based heterocovariance as a drug discovery tool for fishing bioactive compounds out of a complex mixture of structural analogues. Sci Rep. 2019 doi:10.1038/s41598-019-47434–8
• 4 Aligiannis N, Halabalaki M, Chaita E, Kouloura E, Argyropoulou A, Benaki D. et al. Heterocovariance based metabolomics as a powerful tool accelerating bioactive natural product identification. ChemistrySelect 2016; 1: 2531-2535