Analysis of Water-soluble Chemical Constituents of Indigoferae Stachyoidis Radix by UHPLC-DAD-Q-TOF-MS/MS

Abstract:

Objective: An ultra-high-pressure liquid chromatography-diode-array detection-quadrupole time-of-flight mass spectrometric (UHPLC-DAD-Q-TOF-MS/MS) method was established to analyze the chemical constituents of the decoction of Indigoferae Stachyoidis Radix. Method: The chromatographic separation was performed on a Synergi Hydro-RP (2.00 mm×100 mm, 2.5 μm) column using a mobile phase consisting of 0.1% formic acid in water(A)and 0.1% formic acid in acetonitrile (B). The flow rate was 0.3 g· L^-1 and the mass spectrometer was Bruker Daltonics micro TOF-Q equipped with an electrospray ionization (ESI) source. The MS and MS/MS spectra were recorded in the negative ion mode.The capillary voltage is 2 800 V. The range of collision energy of MS² is 11 eV from 25 eV. And a condition of Endogenous collision induced dissociation (CID) is 25 eV from 35 eV, the corresponded MS² energy is 12 eV from 17 eV. Result: 15 compounds in the decoction of Indigoferae Stachyoidis Radix were well isolated and identified as gallic acid, protocatechuic acid-3-O-glucoside, protocatechuic aldehyde, protocatechuic acid, glucosyringic acid, gentisic acid, catechin, epicatechin, four procyanidines and three gambiriins. Conclusion: In addition to the compound epicatechin, the other 14 compounds were first reported in this plant. The results have formed the basis for the exploitation of Indigoferae Stachyoidis Radix and the establishment of a quality control method for Indigoferae Stachyoidis Radix.