Phytochemical study of Seriphidium khorassanicum (syn. Artemisia khorassanica) aerial parts: sesquiterpene lactones with anti-protozoal activity

Abstract

Two new eudesmane-type sesquiterpene lactones, 1β,3α,8α-trihydroxy-11β,13-dihydroeudesma-4(15)-en-12,6α-olide (1) and 1β,4α,8α-trihydroxy-11β,13-dihydroeudesma-12,6α-olide (2), and an unprecedented elemane-type sesquiterpene lactone, 1β,2β,8α-trihydroxy-11β,13-dihydroelema-12,6α-olide (3) along with a known eudesmanolide artapshin (4) were isolated from Seriphidium khorassanicum. Structures were elucidated by NMR, HR-ESI-MS, and ECD spectral data analysis. The anti-protozoal activity was evaluated against Leishmania major promastigotes and amastigote-infected macrophages. They showed dose- and time-dependent activity against L. major amastigotes with IC₅₀ values in the range of 4.9 to 25.3 μM being favourably far below their toxicity against normal murine macrophages with CC₅₀ values ranging from 432.5 to 620.7 μM after 48 h of treatment. Compound 3 exhibited the strongest activity and the highest selectivity index (SI) with IC₅₀ of 4.9 ± 0.6 μM and SI of 88.2 comparable with the standard drug, meglumine antimoniate (Glucantime), with IC₅₀ and SI values of 15.5 ± 2.1 μM and 40.0, respectively.

Graphical Abstract

Keywords:

• Amastigote
• Artemisia khorassanica
• asteraceae
• eudesmanolide
• glucantime
• Leishmania major
• Seriphidium khorassanicum
• sesquiterpene lactone

Disclosure statement

We declare no competing interests.

Additional information

Funding

The authors are grateful to the Vice-Chancellor of Research and Technology, Isfahan University of Medical Sciences, Isfahan, Iran, for its financial support by grant number: 198249.