2.5. Acid Hydrolysis of Compound 1

A methanolic solution (6 mL) of compound 1 (3 mg) was mixed with 1 N HCl (4 mL) and refluxed for 2 h. Then, the solution was concentrated under reduced pressure, diluted with H₂O (8 mL), and extracted with EtOAc to obtain lignan. The sugar was obtained from the aqueous part and identified as d-glucose by TLC system using BuOH : AcOH : H₂O (4 : 1 : 5) as a mobile phase and ceric sulphate as a spraying agent with heating at 130°C on a hot plate.