Metabolomic study of raw and processed Atractylodes macrocephala Koidz by LC-MS.

Bai-Zhu, the dried rhizome of Atractylodes macrocephala Koidz (AMK), is widely used as a tonic herbal in eastern Asia. It is commonly used as prepared slices in clinic by stir-frying with wheat bran (processed AMK). In the theories of traditional Chinese medicine (TCM), Bai-Zhu possesses significantly different therapeutic effects before and after processing. However, the molecular mechanics of this processing is still unknown. In this paper, the strategy of metabolomics was employed to investigate the changes of chemical constituents in Atractylodes macrocephala Koidz after processing. Meanwhile, the cell activity test variation of processed and unprocessed medicine was used to interpret the processing mechanism of AMK. Using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF/MS) with the method of multivariate statistic analyses including principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA), atractylenolide I, atractylenolide II, atractylenolide III, atractylenolide VI, 7-hydroxycoumarin, 8-ß-methoxy atractylenolide I and Selina-4 (14), 7 (11)-dien-8-one were rapidly explored as the potential chemical markers of raw and processed AMK, respectively. Furthermore, it could be speculated that the processing mechanism of AMK was to increase the content of atractylenolide III which could strengthen the effect on gastrointestinal function.

Structure elucidation of degradation products of Z-ligustilide by UPLC-QTOF-MS and NMR spectroscopy.

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.