A simple method for isolation and structural identification of arctigenin from Saussurea medusa Maxim. by preparation chromatography and single crystal X-ray diffraction

Arctigenin was successfully isolated and purified from the crude extract of Saussurea medusa Maxim. by automatic flash preparation chromatography (AFPC). Chromatographic separation was performed with a gradient elution of (A) petroleum ether and (B) acetone. The qualitative analysis was accomplished with thin layer chromatography (TLC) under the following conditions: petroleum etheracetone (5:3, v/v) was used as a developing agent and improved Dragendorff's reagent as a coloring agent at 105°C. The rate of flow is about 0.38, the spot showed reddish yellow. The purity of arctigenin is 99.371%, which was determined by Agilent 1200 high performance liquid chromatograph (HPLC). Its structure was identified by single crystal X-ray diffraction. Arctigenin crystallized in the orthorhombic system, space group P21/n; The unit cell dimensions are as follows: a=9.5649(11) Å, b=10.0929(12) Å, c=20.133(2) Å, α=90°, β=90°, ץ=90°, Z=4.