Metabolite profiling of minor constituents in Salicornia gaudichaudiana by countercurrent chromatography and ESI-MS detection

Salicornia gaudichaudiana (Chenopodiaceae) is a halophyte plant growing in high-level salt soils [1]. In Brazil, plant material is used in food preparations as green salt for people suffering of high blood pressure, kidney and heart diseases. Therefore, the nutritional and chemical properties with the concomitant profile of metabolites are of high interest. The major compounds of S. gaudichaudiana had been studied by preparative countercurrent chromatography (CCC) combined with off-line injections of fractions in the sequence of recovery to an ESI-MS device [2]. In this work, minor constituents of S. gaudichaudiana were investigated using the mentioned method combination. This resulted in the rapid recognition of, at least, 60 target compounds which were identified or partly characterized by molecular weights and ESI-MS/MS fragmentation based on previously isolated compounds [1, 2]. The existing profile of natural products could be divided in four main groups (Fig. 1): (1) chlorogenic acid derivatives, with one, two and three attached caffeoyl-, feruloyl- or dihydro-caffeoyl units, esterificated as methyl quinate or not; (2) flavonoid derivatives, including kaempferol, quercetin and ishorametin aglycones with up to three sugar units; (3) triterpenoid saponins, including calenduloside E differing in the number of sugar units and sugar substituents; and (4) other phenolics, including benzoic and cinnamic acids derivatives. Besides common substituents, losses of m/z 36 and 63 were frequent and could indicate de presence of chlorinated and sulfonated derivatives, respectively.

Fig. 1: Main groups of natural compounds in S. gaudichaudiana EtOAc extract and its possible position of substitution

References:

[1] Isca VMS et al. An overwiew of Salicornia Genus: The phytochemical and pharmacological profile in Natural products Research Rev, V 2, 145 – 176, Daya Publishing House, New Delhi, 2012

[2] Costa FN et al. J Chromatogr A 2015; 1385: 20 – 27