Analysis of the photochemical composition and biological activities of two Onosma species (O.sintenisii and O.mutabile)

This study was aimed to investigate the chemical compositions, in vitro antioxidant and enzyme inhibitory activities of methanol extracts from O. sintenisii and O. mutabile. Spectrophotometric analyzes showed that the total phenolic and flavonoid content of O. mutabile was higher than O. sintenisii. Findings from the chromatographic analyzes also confirmed the spectrophotometric analyses. It was determined that O. mutabile contains high levels of apigenin 7-glucoside and rosmarinic acid. O. mutabile extract exhibited higher activity in all of the antioxidant activity tests. O. sintenisii exhibited higher inhibitory activity on other enzymes except for α-amylase. It was understood that there was a close relationship between the antioxidant activities of the extracts and their chemical compositions. However, it was concluded that more detailed tests should be done to determine the phytochemicals responsible for the enzyme inhibitory activities of the extracts in question. Keywords:Onosma sintenisii,Onosma mutabile,Chemical composition,Antioxidant activity,Enzyme inhibitory activity