UPLC‐QTOF‐MS^E‐based diagnostic product ion filtering to unveil unstable C₆‐C₂ glucoside conjugates in Forsythia suspensa

Abstract

Forsythia suspensa contains C -C glucoside conjugates (CCGCs) that are chemically unstable, thereby hindering their isolation and purification. In the present study, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF) was utilized to screen and identify unstable CCGCs in the fruits and leaves of F. suspensa without any tedious isolation and purified process based on independent information acquisition (also called MS ) and individual MS/MS experiments. Diagnostic product ion filtering (DPIF) was further applied to mine unknown analogs in MS high energy levels based on characteristic m/z of key substructures. A modified nomenclature for CCGCs is hereby proposed to facilitate discussions. Possible fragmentation pathways of major types of known CCGCs were proposed and used for deducing their structures. A total of 8 potentially new CCGCs were discovered and initially identified. The accuracy of their identification was further verified by structural elucidation of 3 unstable CCGCs isolated from the fruits of F. suspensa using 1D and 2D-NMR spectroscopy. The established UPLC-QTOF-MS -based DPIF technique facilitates the rapid discovery and direct identification of unstable CCGCs in fruits and leaves of F. suspensa.

Rapid identification of chemical constituents in Yinqiao powder using ultra‐high‐performance liquid chromatography coupled to quadrupole‐time‐of‐flight tandem mass spectrometry using data filtering strategy

“…The backbone of C6‐C2 glucoside conjugates was glucose with two substituents, including a, b, c, d, f, g, h, i, and j, at C‐1 and C‐6 through glycosidic and/or ester linkages (Xia et al, 2017). A comparative study of their fragmentation behaviors found that there was one backbone ion at m / z 179.0550 existing in all MS/MS spectra of C6‐C2 glucoside conjugates.…”

“…The backbone of C6-C2 glucoside conjugates was glucose with two substituents, including a, b, c, d, f, g, h, i, and j, at C-1 and C-6 through glycosidic and/or ester linkages (Xia et al, 2017)…”

“…Numerous reports have shown that the clinical efficacy of a combination of Yinqiao powder and antibiotics in the treatment of pneumonia is significant (Fan et al, 2021). At present, a large number of studies have focused only on the efficacy of Yinqiao powder in treating pneumonia and the chemical components of a single medicine (Pan et al, 2020; Xia et al, 2017; Zheng et al, 2010; Jaiswal & Kuhnert, 2011; Huang et al, 2021; Chai et al, 2019). Lonicerae Japonicae Flos contains a variety of compounds, such as phenolic acids, flavonoids, and iridoids (Shang et al, 2016).…”

Rapid characterization of chemical constituents and metabolites of Qi‐Jing‐Sheng‐Bai granule by using UHPLC–Q‐TOF‐MS

“…A technique based on UHPLC–Q‐TOF‐MS was introduced employing independent information acquisition named UHPLC–Q‐TOF‐MS Energy can be used to identify most compounds . It could simultaneously detect precursor ions at low collision energy and fragment ions at high energy in a single injection, and greatly improve the efficiency of composition screening and identification .…”

The rapid identification of chemical constituents in Fufang Xiling Jiedu capsule, a modern Chinese medicine, by ultra‐performance liquid chromatography coupled with quadrupole‐time‐of‐flight tandem mass spectrometry and data mining strategy

“…Great challenges still remain in the processing of complex multi-way data derived from LC-MS. Some approaches such as mass defect filtering [9], multiple product ion filtering [10,11], neutral loss filtering [11,12], and fragment ion diagnostic strategy [13] were developed and used to deduce parent and fragment ions. However, these data post-processing technologies developed are based on a single component and may neglect the structure correlations between chemical constituents.…”