Comprehensive characterization of in vivo metabolic profile of Polygalae radix based on ultra-high-performance liquid chromatography-tandem mass spectrometry.

In this study, a novel analysis strategy for progressively targeted screening and characterization of drug ingredients from in vitro to in vivo was proposed based on ultra-high performance liquid chromatography-tandem mass spectrometry for comprehensive characterization of in vivo metabolic profile of Polygalae radix (PR). First, an in vitro chemical profile of PR was described with the assistance of UNIFI™ software. The characteristic neutral small molecule losses were summarized to distinguish different chemical structures in the PR extract. Second, the in vitro intestinal microflora metabolism model was applied to describe an in vitro metabolic profile of the main ingredients of PR. The metabolic rule and metabolites were integrated for subsequent targeted screening of metabolites in vivo. Finally, an integrated strategy was established and applied to screen and characterize the major absorbed components in vivo, including blood, urine, brain, feces, and liver, based on the prototypes and metabolic rules obtained in vitro. As a result, in vitro and in vivo metabolic profiles of PR were effectively depicted. A total of 136 compounds were isolated and identified from the crude extract in vitro, and 12 compounds were reported for the first time based on the proposed fragmentations. A total of 13, 32, and 3 compounds were identified and characterized in the dosed plasma, liver, and brain, respectively. A total of 40 and 73 compounds were identified in urine and feces, respectively. This strategy not only provided a comprehensive insight into the chemical and metabolic profiles of PR but also presented a new perspective for the discovery of new drugs for medicinal application.

A targeted strategy for analyzing untargeted mass spectral data to identify lanostane-type triterpene acids in Poria cocos by integrating a scientific information system and liquid chromatography-tandem mass spectrometry combined with ion mobility spectrometry.

Rapid structural identification of natural compounds in the crude extract of traditional Chinese medicine by conventional liquid chromatography-mass spectrometry is complex and challenging. In particular, it is difficult to distinguish and identify structural isomers. In this work, we proposed a novel strategy that combines a typical ultrahigh-performance liquid chromatography-multidimensional mass spectrometry approach and the post-processing UNIFI scientific information system to rapidly identify lanostane analogs and isomers in Poria cocos. First, this strategy requires setting up a high-resolution key MS database and an in-house compound library. Then, ultrahigh-performance liquid chromatography coupled with high-resolution tandem data-independent mass spectrometry and ion mobility mass spectrometry was used to acquire untargeted multidimensional mass spectral data. Finally, a new and reliable multidimensional MS analytical workflow was developed to targeted filter the acquired data based on an in-house compound library via the UNIFI™ software. As result, a total of 121 lanostane-type triterpene acids were identified by high-resolution molecular mass, fragment ions, and collision cross-section values. Eight triterpene acids were unambiguously identified by comparing the retention time and MS/MS data with those of reference compounds. Three compounds were detected and reported for the first time based on their neutral losses, characteristic ions, and fragmentation pathways compared with those of known compounds. We anticipate that such an analytical approach can be extended to rapidly screen and characterize other herbal medicine compounds with multiple isomers.

Studies on the chemical and intestinal metabolic profiles of Polygalae Radix by using UHPLC-IT-MSn and UHPLC-Q-TOF-MS method coupled with intestinal bacteria incubation model in vitro.

Polygala Radix (PR) is one of the most commonly used traditional Chinese medicines (TCM), but its effective materials are still not very clear. In order to solve the existing problems, the chemical and intestinal metabolic profiles of PR were analyzed via intestinal bacteria incubation model. An integrated analysis method combined ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF MS) method and ultra-high performance liquid chromatography with ion-trap multi-stage tandem mass spectrometry (UHPLC-IT-MSn) method was established. As a result, a total of 115 polygala compounds were identified from the PR extract. Moreover, 44 metabolites via intestinal microflora were characterized, of which three compounds were formed from xanthone C-glycosides, 25 compounds were formed from polygala saponins and 16 compounds were formed from oligosaccharide multi-esters. To our knowledge, the metabolites of the PR via intestinal microflora metabolism, especially polygala saponins, are the first reported in vitro. The obtained results would provide the methodological support for further studying the effective materials of the PR in vivo.