Profiling of glucosinolates and flavonoids in Rorippa indica (Linn.) Hiern. (Cruciferae) by UHPLC-PDA-ESI/HRMS(n)

Abstract

An UHPLC-PDA-ESI/HRMS(n) profiling method was used to identify the glucosinolates and flavonoids of Rorippa indica (Cruciferae), a wild vegetable and Chinese herb used to treat cough, diarrhea, and rheumatoid arthritis. Thirty-three glucosinolates, more than 40 flavonol glycosides, and 18 other phenolic and common organic compounds were identified. The glucosinolates and polyphenols were separated by UHPLC. High-resolution deprotonated molecules provided high accuracy mass values that were used to determine formulas and provide putative identification of the glucosinolates and flavonoids. The fragments from multistage mass spectrometry were used to elucidate the structures. The concentrations of the main components were based on UV peak areas and molar relative response factors with a single calibration standard. This study found this plant to be a rich source for glucosinolates, containing 24 new glucosinolates, including 14 glucosylated glucosinolates that were previously unidentified.

Figure 1

Structures of the glucosinolates of Rorippa indica.

Figure 2

Chromatograms (A, TIC; B, PDA at 354 nm; and C, PDA at 225 nm) of Rorippa indica (only the main glucosinolates and flavonoids are labeled).

Figure 3

Molecular and typical fragments for the glucosinolates in Rorippa indica.

Figure 4

MS² (A) and MS³ (B) spectra of 9-(methylsulfonyl)nonylglucosinolate (GS-1).

Figure 5

MS² spectra of the glucosides (A, GS-19; and B, GS-22) of 9-(methylsulfonyl)nonylglucosinolate.