A new procedure for the preparative separation and isolation of Z-ligustilide from the roots of Angelica sinensis

A new procedure for the separation and isolation of Z-ligustilide from the roots of Angelica sinensis (AS) was developed, and the storage conditions for Z-ligustilide were optimized. Using the present procedure, Z-ligustilide was enriched by decomposing the Z-ligustilide dimers yielding Z-ligustilide and dissolving the polar impurities in hot water. Then, the crude Z-ligustilide was further purified by a semipreparative HPLC system. The spiked and nonspiked samples were used for the evaluation of the proposed procedure. Recoveries obtained varied from 86.2 to 90.7% and RSDs from 4.0 to 6.6%. The yield and purity of the isolated Z-ligustilide were found to be 4.57 mg/g and 99.6%, respectively. The results of stability tests have shown that the presence of oxidant contributes to Z-ligustilide degradation, therefore argon was chosen as a shielding gas for storage. The overall procedure is efficient and convenient which is considered suitable for the preparative separation of Z-ligustilide from AS.