Advances in Isoflavone Profile Characterisation using Matrix Solid‐phase Dispersion Coupled to HPLC/DAD in Medicago Species

Abstract

ABSTRACT:Introduction -Analytical methods used in phytochemistry analysis are limited by the sample preparation step, which should ideally be fast, accurate, ecofriendly and achievable using low quantities of the sample. Matrix solid-phase dispersion (MSPD) may be a good alternative for combining extraction and purification procedures, thereby reducing the indicated limitations. Objective -Applying an MSPD extraction procedure coupled to high-performance liquid chromatography diode-array detection (HPLC/DAD) as an alternative methodology to evaluate isoflavone profiles. Methods -Isoflavone profiles were determined for the leaves of nine species of Medicago in the late flower phenological stage (one or more nodes with 50% open flowers, no seed pods). Extraction was performed following MSPD, and isoflavone profiles were characterised using HPLC/DAD. The quantified amounts were compared with previous results in different species commonly recognised as good sources of isoflavones. Results -Formononetin was the major isoflavone in most species, except M. polymorpha and M. truncatula. The isoflavone amounts were significantly different among the assayed species, with M. orbicularis and M. arabica as the major isoflavone sources, while M. rigidula presented the lowest contents. Furthermore, the detected differences allow electing the best species as a primary source of a specific isoflavone. Conclusion -The MSPD allowed good extraction efficiency, reproducibility and recovery. Some of the species showed relevant isoflavone contents, even when compared with acknowledged plant sources such as soy or red clover. To the best of our knowledge the results presented are reported for the first time in these species.

Medicago spp. as potential sources of bioactive isoflavones: Characterization according to phylogenetic and phenologic factors

“…Besides the chromatographic data, the proposed identification was also supported by UV spectra as described previously (Rodrigues et al, 2014). Chromatographic parameters, namely limit of detection (LOD), limit of quantification (LOQ), linearity, recovery and repeatability were accepted as previously assessed (Visnevschi-Necrasov et al, 2014a).…”

“…MSPD extraction of isoflavones was performed following a previous method (Visnevschi-Necrasov et al, 2014a). The same amounts of sample, C 18 and internal standard (2-methoxyflavone) were used.…”

“…Soybean, for instance, present mainly isoflavone aglycones (daidzein, glycitein and genistein) and glycoside, acetylglycoside and malonylglycoside forms. In contrast to soybean, red clover contains biochanin A and formononetin (aglycones), and their glycosides and malonyl derivatives as the major components, while in Medicago species, the most abundant isoflavones are formononetin, irilone and genistein (Visnevschi-Necrasov et al, 2014a). The isoflavones profile also varied greatly with the phenological stage, varying along the plant maturity (D'Agostina et al, 2008).…”

“…Chromatographic analyses were performed following the previously optimized methodology (Visnevschi-Necrasov et al, 2014a). A high-performance liquid chromatograph (Jasco, Tokyo, Japan) equipped with a PU-2080 quaternary pump and a Jasco AS-950 automatic sampler were used.…”

Phytochemical profiling of underexploited Fabaceae species: Insights on the ontogenic and phylogenetic effects over isoflavone levels

“…In the case of isoflavone production, the studied species are usually limited to soybean (Glycine max L.) and red clover (Trifolium pratense L.). Nevertheless, some alternative species are being studied to evaluate their potential use as isoflavone sources Jacobs, Wegewitz, Sommerfeld, Grossklaus, & Lampen, 2009;Spínola, Llorent-Martínez, Gouveia-Figueira, & Castilho, 2016;Visnevschi-Necrasov et al, 2014. The species studied in this work (Biserrula pelecinus L., Lotus conimbricensis Brot., Lotus subbiflorus Lag., Ornithopus compressus L., Ornithopus pinnatus (Mill.)…”