Pharmacognostical studies on Verbascum uschakense (MURB.) HUB.-MOR

Verbascum L., the largest genus of the Scrophulariaceae family and classified under 13 groups (A-M) in the Flora of Turkey, is one of our country's important natural resources having a high endemism rate. Many species belonging to the genus Verbascum are traditionally used to treat diseases in our country and around the world. Conducting phytochemical and biological activity studies on V. uschakense (Murb.) Hub.-Mor., which is included in group K, was aimed in this study. An 85% ethanol extract was obtained from the air-dried and powdered aerial parts of the plant, as well as the corresponding sub-extracts obtained by partitioning this extract with n-hexane, dichloromethane, ethyl acetate, and n-butanol. Acetylcholinesterase enzyme inhibitory and DPPH radical scavenging activities of the preliminary fractions obtained from n-butanol extract by polyamide column chromatography were tested. Starting from the active fractions, 5 iridoid glucosides (VU-1: glucoside, VU-2: ajugol, VU-3: harpaget, VU-4: okubin, VU-5: catalpol) and 3 phenylethanoid glycosides (VU-6: verbascoside, VU-7: martinoside, VU-8: forcytoside B) were isolated using appropriate chromatographic methods. The structures of the obtained compounds were elucidated by 1D-, 2D NMR, and mass spectroscopy methods.