Browsing by Author "Sahinler S.S."

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    Nutraceutical extracts from some endemic Onosma (O. circinnata, O. bornmuelleri, and O. angustissima) species: LC–ESI-MS/MS–based polyphenol profile, antioxidant and enzyme inhibition activities
    (John Wiley and Sons Inc, 2021) Sarikurkcu C.; Sahinler S.S.; Ozer M.S.; Sihoglu Tepe A.
    This study aimed to determine the chemical composition of methanol extracts from Onosma circinnata, Onosma bornmuelleri, and Onosma angustissima and to investigate their antioxidant and enzyme inhibitory activities. Spectrophotometric analysis showed that the extracts were found to be rich in chlorogenic acid, luteolin 7-glucoside, rosmarinic acid, and apigenin 7-glucoside. While O. bornmuelleri showed the highest activity in DPPH, ABTS, and FRAP tests, O. circinnata was more effective in CUPRAC, phosphomolybdenum, and ferrous ion chelating tests. While O. angustissima showed significant inhibitory activities on AChE, BChE, and tyrosinase, O. bornmuelleri and O. circinnata showed the highest inhibitory activities on α-amylase and α-glucosidase. It was concluded that O. circinnata and O. bornmuelleri are effective antioxidant agents and O. angustissima can be considered as an alternative agent in the medical and cosmetic industries due to its ChE and tyrosinase inhibitory activities. Novelty impact statement: Biological activities of Onosma species were brought to the literature for the first time with this study. O. circinnata showed remarkable antioxidant activity. O. angustissima exhibited the highest AChE, BChE and tyrosinase inhibitory activity. © 2021 Wiley Periodicals LLC.
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    Chromatographic profile and antioxidant and enzyme inhibitory activity of Sideritis leptoclada: An endemic plant from Turkey
    (Elsevier B.V., 2021) Sarikurkcu C.; Ozer M.S.; Istifli E.S.; Sahinler S.S.; Tepe B.
    Sideritis species have been used for centuries for their antimicrobial, digestive, anti-ulcerogenic and anti-inflammatory properties. Therefore, in this study, it was aimed to evaluate the chemical composition, antioxidant and enzyme inhibitory activities of solvent extracts of S. leptoclada O. Schwarz & P.H. Davis, an endemic species. It was determined that methanol (MeOH) and water extracts contained high amounts of chlorogenic acid and verbascoside, while the ethyl acetate (EtOAc) extract contained high amounts of 4-hydroxybenzoic and vanilic acids. The water extract showed the highest antioxidant activity in almost all parameters. Inhibitory activity of the MeOH extract on tyrosinase was 1.04 mg/ml, which was the highest value in this experiment. On the other hand, in α-amylase inhibitory assay, the EtOAc extract showed an activity of 2.21 mg/ml. Docking analysis showed that verbascoside can be an effective tyrosinase and α-amylase inhibitory agent. © 2021 SAAB