Laguncularia racemosa Phenolics Profiling by Three-Phase Solvent System Step-Gradient Using High-Performance Countercurrent Chromatography with Off-Line Electrospray Mass-Spectrometry Detection

Abstract

The detailed metabolite profiling of Laguncularia racemosa was accomplished by high-performance countercurrent chromatography (HPCCC) using the three-phase system n-hexane–tert-butyl methyl ether–acetonitrile–water 2:3:3:2 (v/v/v/v) in step-gradient elution mode. The gradient elution was adjusted to the chemical complexity of the L. racemosa ethyl acetate partition and strongly improved the polarity range of chromatography. The three-phase solvent system was chosen for the gradient to avoid equilibrium problems when changing mobile phase compositions encountered between the gradient steps. The tentative recognition of metabolites including the identification of novel ones was possible due to the off-line injection of fractions to electrospray ionization mass spectrometry (ESI-MS/MS) in the sequence of recovery. The off-line hyphenation profiling experiment of HPCCC and ESI-MS projected the preparative elution by selected single ion traces in the negative ionization mode. Co-elution effects were monitored and MS/MS fragmentation data of more than 100 substances were used for structural characterization and identification. The metabolite profile in the L. racemosa extract comprised flavonoids, hydrolysable tannins, condensed tannins and low molecular weight polyphenols.

Allelopathic Potential of Mangroves from the Red River Estuary against the Rice Weed Echinochloa crus-galli and Variation in Their Leaf Metabolome

“…The BPC major compound Ac M1 ( Figure S7 ) might be myricetin-3-glucoronid ( Figure S2a ), found in the leaves of mangrove Conocarpus erectus [ 42 ]. The BPC major compound Ac M2 ( Figure S8 ) could be a quercetin glucuronide already described in Laguncularia racemosa [ 43 ], while the BPC major compound Ac M3 ( Figure S9 ) could be kaempferol-3-glucoside, also known as astragalin ( Figure S2b ). Vinh et al, 2019 reported this metabolite in A. corniculatum leaves, supporting our assumptions [ 41 ].…”

Recent trends in multidimensional countercurrent chromatography

“…Their approach employed a quick ultra-performance liquid chromatography under voltage (UPLC-UV) method to qualitatively and quantitatively analyze four glycoside isomers found in the leaves of Idesia polycarpa maxim. They examined and validated the chemical characteristics of those isomers using various analytical tools such as UV, UPLC, Fourier-transform infrared, ESI-MS, 1 H-NMR, 13 C-NMR, and 2D-NMR spectra [57,70,75,85].…”