Antioxidant and enzyme inhibitory activities of disodium rabdosiin isolated from Alkanna sfikasiana Tan, Vold and Strid

Alkanna sfikasiana Tan, Vold and Strid is an endemic Greek species of Boraginaceae family. From the roots, the new natural product disodium rabdosiin (1) along with rosmarinic acid (2) were isolated from the methanolic extract and lanosta-7,24-dien-3β-ol (3) and linoleic acid (4) from the cyclohexane extract. From the methanolic extract of the aerial parts two flavonoids quercetin 3-Ο-β-D-glucoside (5) and quercetin 3-Ο-β-D-rutinoside (6) were isolated. The antioxidant properties exhibited good radical scavenging activity (96.00 mgTE/g for DPPH; 441.97 mgTE/g for ABTS) and reducing power ability (720.81 mgTE/g for CUPRAC and 413.94 mgTE/g for FRAP) for the new compound 1. Enzyme inhibitory activity has been also evaluated, showing inhibitory effects on AChE (4.32 mgGALAE/g), BChE (3.63 mgGALAE/g) and α-amylase (3.83 mmolACAE/g). Consequently, our study could provide a potential candidate for developing novel phyto-pharmaceutics and it could be considered a new starting point on the studied species.