Preparation of periplocymarin from Cortex Periplocae

Periplocymarin was prepared by a modified version of enzymatic hydrolysis method as described in previous studies with some modifications. Briefly, the dry Cortex Periplocae were extracted with water. The water extraction was concentrated and 85% ethanol was added to remove the insoluble parts. The ethanol solution was further concentrated to remove ethanol and extracted thrice with diethyl ether, ethyl acetate and n-butyl alcohol, successively. The n-butyl alcohol extraction (10.0 g) was enzymatically hydrolyzed with 0.6% helicasein citric acid and sodium citrate buffer (pH = 5.5, 100 mL) at 50°C for 24 h. The aqueous residue was extracted with dichloromethane-methanol and washed with water. After removal of the solvent, the residue was purified by means of C₁₈ column chromatography to yield compound 1 (164 mg). Compound 1 was identified as periplocymarin by spectroscopic analyses and compared with published data.