Structure elucidation of degradation products of Z-ligustilide by UPLC-QTOF-MS and NMR spectroscopy.
- Author:
Aihua ZUO
;
Mengchun CHENG
;
Rongjie ZHUO
;
Li WANG
;
Hongbin XIAO
- Publication Type:Journal Article
- From:
Acta Pharmaceutica Sinica
2013;48(6):911-6
- CountryChina
- Language:English
-
Abstract:
Z-Ligustilide, a major phthalide isolated from a widely used traditional Chinese medicine Ligusticum chuanxiong, possesses various pharmacological activities including neuroprotective, anti-inflammatory, antiproliferative and vasorelaxing effects. However, it is unstable and inclined to degrade in natural conditions, which limits its study and application greatly. In this study, degradation behavior of Z-ligustilide and its degradation products stored at room temperature under direct sunlight were investigated and structure elucidated by HPLC-UV, UPLC-QTOF-MS and NMR. Z-ligustilide degradation and total five degradation products were generated and detected. Two degradation products were unequivocally identified as senkyunolide I and senkyunolide H by comparison with reference compounds. Another two degradation products were further isolated by semi-preparative HPLC and structure elucidated as (E)-6, 7-trans-dihydroxyligustilide and (Z)-6, 7-epoxyligustilide by 1H and 13C NMR, respectively. The degradation pathways of Z-ligustilide were finally proposed. Oxidation, hydrolysis and isomerization are the major degradation reactions.
