1H NMR Fingerprinting of Soybean Extracts, with Emphasis on Identification and Quantification of Isoflavones

Abstract

1H NMR spectra were recorded of methanolic extracts of seven soybean varieties (Glycine max.), cultivated using traditional and organic farming techniques. It was possible to identify signals belonging to the groups of amino acids, carbohydrates, organic acids and aromatic substances in the spectra. In the aromatic zone, the isoflavone signals were of particular interest: genistein, daidzein, genistin, daidzin, malonylgenistin, acetylgenistin, malonyldaidzin signals were assigned and these compounds were quantified, resulting in accordance with published data, and further demonstrating the potential of the NMR technique in food science.

Flavonoid Derivatives from the Aerial Parts of Trifolium trichocephalum M. Bieb. and Their Antioxidant and Cytotoxic Activity

“…Fraction 4 (25 mg) gave compound 1 (20 mg). The fractions 5-17 (0.8 g) were combined and further applied to silica gel column chromatography using 1 H NMR and 13 C NMR data agree with the data given in the literature for genistein [13,14] (Figure 1). C-7), 161.1 (C-5), 156.6 (C-9), 148.1 (C-4'), 147.2 (C-2), 145.5 (C-3'), 136.1 (C-3), 122.4 (C-1'), 120,5 (C-6'), 116.0 (C-5'), 115.4 (C-2'), 103.4 (C-10), 98.6 (C-6), 93.8 (C-8) 1 H NMR and 13 C NMR data agree with the data given in the literature for quercetin [15] (Figure 1).…”

“…By this point of view, the ethyl -acetate and water subextracts of the MeOH extract were separated using chromatographic methods to obtain four compounds in total. The structures of the isolated compounds, elucidated by 1 H and 13 C NMR experiments, were identified as daidzein, genistein, quercetin, and daidzein 4'-O-D-glucoside by comparison of their spectroscopic data (UV, 1D-and 2D-NMR, and MS) with previously published data [13][14][15][16]. Furthermore, the radical scavenging effect and cytotoxicity of the methanol extract and water, ethyl acetate, and chloroform subextracts of T. trichocephalum as well as four compounds isolated from this plant were examined.…”

Integration of Microfractionation, qNMR and Zebrafish Screening for the In Vivo Bioassay-Guided Isolation and Quantitative Bioactivity Analysis of Natural Products

“…In addition, the PDA spectrum presented an absorption maximum (λ max ) at 260, 290 sh and 325 sh nm characteristic for isoflavones such as genistein. Compound a was easily confirmed to be genistein (Figure 4) by the comparison of the 1 H NMR spectrum of the corresponding microfraction obtained by microflow NMR (CapNMR™) with literature values [32]. In all the fractions collected in the 30.0–33.0 min region, the 1 H signals of genistein were present confirming it to be responsible for the in vivo anti-angiogenic activity observed (Figure 3D).…”

Compositional study of different soybean (Glycine max L.) varieties by 1H NMR spectroscopy, chromatographic and spectrometric techniques

“…1B to further display the difference between glyphosate-tolerant and Chinese conventional soybeans. It can be seen that carbohydrates (d = 3.0-4.0), glucose (d = 5.2), glutamic acid (d = 2.1), and fatty acids (d = 2.0, 2.3) were the discriminatory compounds between glyphosate-tolerant and Chinese conventional soybeans (Baker et al, 2006;Caligiani, Palla, Maietti, Cirlini, & Brandolini, 2010). Apart from 1 H NMR data, the compositional profiles of amino acids, fatty acid, sugars, elements, and isoflavones from different soybean varieties were also discriminated by PCA.…”