Serratula wolffii, as a source of new ecdysteroids

Ecdysteroids were discovered as steroid hormones of arthropods. They regulate moulting, metamorphosis, reproduction and diapause of insects. [1] The functional analogues of ecdysteroids were used as selective pest control agents. Phytoecdysteroids are structurally related to the main insect hormone ecdysone. The levels of ecdysteroids in plants are generally between 0.1–3% of the dry weight. Their easy availability in plants allowed pharmacological studies, which demonstrated that they influence many physiological functions in a positive way and they are not toxic to mammals. Their most pronounced effect on mammals is a stimulation of protein synthesis without adverse androgenic, antigonadotropic, thymolytic side effects. Ecdysteroid-inducible gene expression system is a new line of biomedical application of ecdysteroids [2]. We now report the isolation and structure determination of five new ecdysteroids from the roots of Serratula wolffii. The isolation of compounds from the methanol extract involves simple cleanup using precipitation and combined chromatographic procedures, including CC on polyamide and C₁₈, RPC and preparative HPLC. The newly discovered ecdysteroids are as follows: 14,15α-epoxy-(20R,22R,)-2β,3β,20,22,25-pentahydroxy-5β-cholesta-7,14-dien-6-one, (20R,22R)-2β,3α,20,22,25- pentahydroxy-5β-cholesta-7-en-6-one, 22-methylene-2β,3β,11α, 14α,25-pentahydroxy-5β-cholesta-7-en-6-one, 2β,3β,14α,25-tetrahydroxy-5β-cholesta-7,20(22)-dien-6-one, 1β,2β,3β,14α,25-pentahydroxy-5β-cholesta-7,20(22)-dien-6-one. The structures of compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.

References: [1] Dhadialla, T.S. et al. (1998) Annu. Rev. Entomol. 43: 545–569. [2] Lafont, R. et al. (2003)J. Insect Sci. 3: 7:1–30.