Figure 4.
Relative quantification of identified compounds in different solvent extracts of OPL based on the mean peak areas of selected 1H-NMR signals. (A) Carbohydrates and amines; (B) organic acids; (C) flavonoids. The discriminating chemical shifts (ppm) employed for the relative quantification were sucrose (δ 3.82), fructose (δ 4.18), α-glucose (δ 5.18), β-glucose (δ 4.62), choline (δ 3.20), citric acid (δ 2.74), succinic acid (δ 2.54), aconitic acid (δ 3.42), α-linolenic acid (δ 1.30), acetic acid (δ 2.07), palmitic acid (δ 0.9), fatty acid (δ 1.34), (+)-catechin (δ 7.02), (−)-epicatechin (δ 6.94), orientin (δ 7.54), isoorientin (δ 7.40), vitexin (δ 8.02), and isovitexin (δ 7.79). Bars labelled with the different letters (a,b,c,d) are significantly different between solvent extracts for the same metabolites (p < 0.05).