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Chemical Constituents of Two Endemic Sideritis Species fr

Sema Çarıkçı, Turgut Kılıç, Akın Azizoğlu and Gülaçtı Topçu

Balıkesir University, Faculty of Arts and Science, Department of Chemistry, 10145,Balıkesir, Türkiye

Bezmialem Vakıf University, Faculty of Pharmacy, Deparment of Pharmacognosy 34093, Fatih-Istanbul, Türkiye

Abstract: In this study, two Sideritis species, endemic to Turkey, S. niveotomentosa Huber – Morathii, S.brevidens P.H. Davis have been studied for their diterpenic compounds and the antioxidant properties. Eight known diterpenoids, which have ent-kaurene skeleton, were isolated from acetone and methanol extracts of these species. The structures of the isolated diterpenes were determined by using the NMR ( 1H-NMR, 13C-NMR, COSY, HMQC, and HMBC ) spectroscopy. The analysis of the phenolic compounds of the extracts was performed by high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Also the antioxidant capacity of the extracts was investigated namely by two methods; free radical scavenging and β-carotene bleaching activities.

Keywords: Lamiaceae; Sideritis niveotomentosa ; Sideritis brevidens ; diterpenoids; kaurane; antioxidant potential.