Analgesic compounds from Scorzonera latifolia (Fisch and Mey.) DC.

Ethnopharmacological relevance: A traditional mastic named yakı sakızı prepared from the roots of Scorzonera latifolia (Fisch. and Mey.) DC. is used as a folk remedy for treatment of pain in Turkish folk medicine. Aim of the study: To isolate and identify the compounds responsible for the antinociceptive activity of S. latifolia using bioassay-guided fractionation. Materials and methods: The methanolic extract of the S. latifolia roots was prepared and subjected to isolation procedures such as solvent–solvent partitioning and column chromatography. Writhing and tail-flick tests were used to determine the antinociceptive activity. Results: The n-hexane fraction of the S. latifolia root methanolic extract showed potent antinociceptive activity in both writhing and tail-flick tests. Three compounds were isolated from n-hexane fraction using bioassay-guided chromatographic purification. Isolated compounds were the triterpene taraxasteryl myristate, taraxasteryl acetate, and fern-7-en-3--one, structures were elucidated by means of MS and NMR techniques. Both taraxasterol derivatives showed promising antinociceptive activity when compared to reference compounds. Conclusion: Results of the present study support the usage of S. latifolia in Turkish folk medicine. Both plant root extract and the isolated compounds showed promising antinociceptive activities. Our results suggested that antinociceptive activity of the plant extract is probably caused by the synergistic interaction of the isolated compounds.