Ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry combined with statistical analysis for rapidly revealing the influence of sulfur-fumigated Paeoniae Radix Alba on the chemical constituents of Si Wu Tang

Abstract

It is well documented that sulfur-fumigation may induce chemical transformation of Paeoniae Radix Alba. However, the influence of sulfur-fumigated Paeoniae Radix Alba on the chemical constituents of traditional Chinese medicinal formulae has never been reported and confirmed. In the present study, a new strategy was proposed to rapidly reveal the difference of chemical constituents between Si Wu Tang containing sun-dried and sulfur-fumigated Paeoniae Radix Alba by ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry in both negative and positive ion modes combined with principal component analysis and T-test statistical analysis. A total of sixty-six components were identified in both Si Wu Tang containing sun-dried Paeoniae Radix Alba samples and Si Wu Tang containing sulfur-fumigated Paeoniae Radix Alba samples by using target compound analysis. Additionally, forty-seven marker compounds that differentiate Si Wu Tang containing sulfur-fumigated Paeoniae Radix Alba from Si Wu Tang containing sun-dried Paeoniae Radix Alba were found and identified, in which eleven were sulfites that were generated in Si Wu Tang containing sulfur-fumigated Paeoniae Radix Alba, and others were derived from the decomposition of ester compounds and glycosides in all four medicinal herbs of Si Wu Tang due to the existence of sulfinic acid and sulfuric acid when sulfur-fumigated Paeoniae Radix Alba was used. The structures of marker compounds were identified by accurate mass (error) and purity score (obtained by matching a MS/MS pattern from the library to an experimental MS/MS spectrum, based on the relative intensity of the precursor and products). It was proved that the established method could be successfully applied to discriminate Si Wu Tang containing sun-dried and sulfur-fumigated Paeoniae Radix Alba. Meanwhile, the results revealed that sulfur-fumigated Paeoniae Radix Alba could affect the chemical constituents of the other three medicinal herbs in Si Wu Tang in addition to its own chemical transformation, which might alter bioactivities and pharmacokinetics of Si Wu Tang.