Phytochemical investigation, isolation and structure elucidation of bioactive compounds of the roots of Alkanna methanaea Hausskn.

Alkanna methanaea Hausskn. is an endemic Greek species belonging to the Boraginaceae family. Although the genus Alkanna is mostly known for its lipophilic red pigments alkannins/shikonins and related isohexenylnaphthazarins found in the roots, it also contains a non-negligible amount of hepatotoxic pyrrolizidine alkaloids [1]. Thus, the aim of the present study was the extensive phytochemical investigation of A. methanaea cyclohexane and methanol root extracts. After the extraction, a qualitative investigation was performed using analytical techniques such as HPLC, UHPLC-ESI-HRMS/MS and GC-MS. Subsequent fractionation of the extracts with numerous preparative techniques such as FCPC, column chromatography, Sephadex gel chromatography and preparative HPLC led to the isolation of the secondary metabolites, for the final structure elucidation of which, 1 & 2D NMR were employed. Conclusively, the phytochemical study of the cyclohexane extract led to the identification of 22 non-polar compounds and isolation of 4 known alkannins’ mixture, whereas 3 phenolic compounds, 1 nucleoside, 6 lignans the 3 of which were isolated for the first time in Alkanna genus. Moreover, 5 pyrrolizidine alkaloids among which 2 new natural products and 1 derivative which was isolated for the first time in Boraginaceae family, were isolated and identified from the methanol extract. To our knowledge, this is the first time that Alkanna methanaea Hausskn. is being phytochemically investigated.

Funding ERDF, “RESEARCH–CREATE- INNOVATE”, CosmAGE (project code Τ2ΕΔΚ-02583)

 

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Conflict of Interest

The authors declare no conflict of interest.

• References

• 1 EA Abdel-Gelil O.. et al. Journal of Food Science and Nutrition Research 2019; 2: 309-315

Publikationsverlauf

Artikel online veröffentlicht:
16. November 2023