Profiling the constituents of Dachuanxiong decoction by liquid chromatography with high-resolution tandem mass spectrometry using target and nontarget data mining.

Comprehensive characterization of the large number of compounds existing in traditional Chinese medicines is still a great challenge. In this study, a strategy of precursor ion selected acquisition coupled with target and nontarget data mining was established to systematically characterize the chemical constituents of traditional Chinese medicines. This strategy consisted of four steps: (1) precursor ion selected acquisition was developed to trigger additional tandem mass spectrometry fragmentation reactions, especially for trace constituents; (2) in-house database of compounds was established and diagnostic characteristics were summarized; (3) compounds were identified by target and nontarget data mining; and (4) compound structures were elucidated based on accurate mass matching and comparison of fragment ions, and isomers were discriminated by the intensity of fragment ions, fragmentation pattern analysis, and calculated log P values. This strategy was successfully applied to comprehensively identify the constituents in Dachuanxiong decoction. Finally, a total of 218 compounds assigned to six categories were characterized, and 107 compounds were characterized by nontarget analysis for the first time. In addition, three new diagnostic characteristics of esters of citric acids were elucidated. This research enriched the material basis of Dachuanxiong decoction and provided a new strategy for identifying the chemical constituents of other traditional Chinese medicines.

[Studies on constituents of Polygonum multiflorum extract in vivo and in vitro based on UPLC-Q-TOF-MS].

To explore the drug-induced constituents in vivo of Polygonum multiflorum extract (PM). This study was the first to study the drug-induced constituents in target organ liver. Agilent MassHunter qualitative analysis software and Metabolite ID software were applied for the analysis of retention time, exact relative molecular mass, primary and secondary mass spectrum information based on ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and targeted-MS/MS. By comparison with literature and standards, a total of 5 prototypes and 6 metabolites were identified or tentatively elucidated from the liver samples. In addition, the drug-induced constituents in plasma and PM were also analyzed in this study and 8 prototypes and 19 metabolites were detected from the plasma samples, while 30 compounds were detected from the extract of PM. Emodin oxidative acetylation metabolites, hydroxyl methylation metabolites, carboxylation glucuronidation metabolites and ketone glucuronidation metabolites in this study were first reported. Through the comparative analysis between the in vivo and in vitro constituents of PM, the study preliminarily revealed the drug-induced constituents (prototypes and metabolites) in liver and clarified the transfer process and transmutation rules of constituents in PM, blood and liver, which would further deepen our understanding on constituents of PM in vivo.

Preparing the key metabolite of Z-ligustilide in vivo by a specific electrochemical reaction.

The key in vivo metabolites of a drug play an important role in its efficacy and toxicity. However, due to the low content and instability of these metabolites, they are hard to obtain through in vivo methods. Electrochemical reactions can be an efficient alternative to biotransformation in vivo for the preparation of metabolites. Accordingly, in this study, the metabolism of Z-ligustilide was investigated in vitro by electrochemistry coupled online to mass spectrometry. This work showed that five oxidation products of the electrochemical reaction were detected and that two of the oxidation products (senkyunolide I and senkyunolide H) were identified from liver microsomal incubation as well. Furthermore, after intragastric administration of Z-ligustilide in rats, senkyunolide I and senkyunolide H were detected in the rat plasma and liver, while 6,7-epoxyligustilide, a key intermediate metabolite of Z-ligustilide, was difficult to detect in vivo. By contrast, 6,7-epoxyligustilide was obtained from the electrochemical reaction. In addition, for the first time, 6 mg of 6,7-epoxyligustilide was prepared from 120 mg of Z-ligustilide. Therefore, electrochemical reactions represent an efficient laboratory method for preparing key drug metabolites.

Global Metabolomics Reveals the Metabolic Dysfunction in Ox-LDL Induced Macrophage-Derived Foam Cells.

Atherosclerosis (AS) is a chronic disorder of large arteries that is a major risk factors of high morbidity and mortality. Oxidative modification LDL is one of the important contributors to atherogenesis. Macrophages take up ox-LDL and convert into foam cells, which is the hallmark of AS. To advance the understanding of the metabolic perturbation involved in ox-LDL induced macrophage-derived foam cells and discover the potential biomarkers of early AS, a global metabolomics approach was applied based on UHPLC-QTOF/MS. Multivariate statistical analyses identified five metabolites (25-azacholesterol, anandamide, glycocholate, oleoyl ethanolamide, and 3-oxo-4, 6-choladienoate) for distinguishing foamy macrophages from controls. Among the six main metabolic pathways, the unsaturated fatty acid, especially arachidonic acid metabolism, contributed importantly to early AS. A new biomarker, anandamide (AEA), whose synthesis and metabolism in macrophages are disturbed by overloaded ox-LDL, results in metabolic obstruction. This study is the first to investigate the metabolic disturbance in macrophage-derived foam cells induced by ox-LDL and screen potential biomarkers and metabolic pathways associated with early AS. Our findings provide a new insight in the underlying pathophysiological mechanisms and also help to identify novel targets for the intervention of AS.