Mass Tree Similarity Filtering Technology And Herbs Epimedium Monomer And Identification Of Metabolites Found In The Research And Application Of New Strategies

The discovery and identification of in vivo components and metabolites of traditional Chinese medicine (TCM) is helpful to clarify the material basis of TCM, and pharmacokinetic characteristics of TCM. However, due to the structure diversity of compounds in TCM, the complexity of biological matrix and the low level of in vivo components and metabolites, it is bottleneck to thoroughly and efficiently probe and identify components and metabolites in vivo for TCM.In this paper, a new strategy to discover and identify components and metabolites in vivo of TCM was established by high-performance liquid chromatography with high resolution mass spectrometry/multiple-stage mass spectrometry (HPLC-HRMS/MSn) and a mass spectral trees similarity filter (MTSF) technique. The mass spectral trees of detected compounds were constructed by full-scan mass spectra as the stem and data-dependent subsequent stage mass spectra as branches. The mass spectral trees of known compounds were entered the mass spectral trees library. Potential metabolites were discovered based on the similarity between their mass spectral trees and that of compounds in a mass spectral trees library. The threshold value for match similarity scores was set at above200, allowing approximately80%of interference to be filtered out. A total of115metabolites of five flavonoid monomers (epimedin A, epimedin B, epimedin C, icariin, and baohuoside I) and herbal extract of epimedium were discovered and identified in rats via this new strategy. A metabolic pathway for epimedium flavonoids was proposed. In addition, comparing to the widely used other techniques, the MTSF technique showed better selectivity for probing metabolites than neutral loss filter (NLF) and product ion filter (PIF) techniques, however the MTSF technique and mass defect filter (MDF) technique were complementary. The MTSF technique also presented superiority for identification of metabolites. The MTSF technique is very useful to discovery and identification of components and metabolites of TCM from complicated biological matrix.