Ultrasound-Assisted Extraction of Verbascoside from Leaves for Analysis of Antioxidant and Antidiabetic Activities.

Verbascoside (VER) is a phenylethanoid glycoside compound found in species and is an important part of traditional medicine. It is found in the leaves of , which is taken as a soup or vegetable and also utilized in traditional medicine by the people of Northeast India, especially against hypertension and diabetes. In the present study, VER was extracted from leaves using ultrasound-assisted extraction through the solvent extraction method (ethanol-water, ethanol, and water). The ethanol extract had the highest phenolic and flavonoid contents, ., 110.55 mg GAE/g and 87.60 mg QE/g, respectively. HPLC and LC-MS were used to identify the active phenolic compound, and VER was found to be the main component present in the extraction with a molecular weight of 624.59 g/mol. NMR (H, 2D-COSY) analysis showed the presence of hydroxytyrosol, caffeic acid, glucose, and rhamnose in the VER backbone. Further, different antioxidant activities and antidiabetic and antihyperlipidemia enzyme markers' inhibition against VER-enriched ethanol extract were evaluated. The results showed that ultrasound extraction of polyphenols using ethanol from could be a promising technique for the extraction of bioactive compounds.