Diversity of the composition and content of soluble carbohydrates in seeds of the genus Vicia (Leguminosae)

Abstract

Low molecular weight carbohydrates of seeds of 10 species of Vicia, namely: V. angustifolia, V. articulata, V. cordata, V. ervilia, V. johannis, V. macrocarpa, V. monantha, V. narbonensis, V. pannonica and V. sativa were analyzed by the high resolution gas chromatography method. Seeds of the investigated species contain common (glucose, fructose, myo-inositol, sucrose, galactinol, di-galactosyl myo-inositol and raffinose family oligosaccharides—RFOs) and species-specific carbohydrates (d-pinitol and its α-d-galactosides—in V. articulata, V. monantha and V. pannonica or d-ononitol and its galactoside—in V. ervilia). Among the species containing in seeds RFOs as the main α-d-galactosides (V. angustifolia, V. cordata, V. johanensis, V. macrocarpa, V. narbonensis and V. sativa), an additional subgroup can be separated, which contains a set of unknown compounds (found in V. angustifolia, V. cordata and V. macrocarpa). Moreover, several other unidentified carbohydrate-containing compounds were detected exclusively in seeds of V. ervilia. The concentrations of total soluble carbohydrates (TSCs), including sugars, RFOs, cyclitols and galactosyl cyclitols and unknown compounds, in seeds differ significantly (P < 0.05) among the species. RFOs and sucrose are the main fractions in TSCs, with the exception of V. pannonica seeds, containing more galactosyl pinitols, and V. ervilia, in which unknown compounds account for 50% of TSCs. In V. ervilia RFOs occur at the lowest concentration (9.32 mg g−1 seeds), and the concentration of DGMI (di-galactosyl myo-inositol) is comparable with that of RFOs, which is unusual among all the investigated Vicia species.