Non-traditional sources of anthocyanins: flowers of centaurea cyanus (cornflower)

By reverse-phase HPLC with diode-matrix and mass spectrometric detection the species composition of anthocyanins of cornflower petals (Centaureacyanus) of the three colors: blue, red and maroon was determined. For the first time, the anthocyanin composition of cornflower flower extract of dark maroon color, was found to include including the same anthocyanins as cornflower flowers of traditional blue color, but with another ratio. The main component is cyanidin-3-O-(6”-malonylglucoside)-5-glucoside (37-58 mol. %) at outstanding overall anthocyanin accumulation reaching 3.5 ±0.4 and even 9.5 ± 1.0 g per 100 g of fresh and dried plant material, correspondingly. Meanwhile the anthocyanin set of blue cornflowers includescyanidin-3,5-diglucoside (23-25 mol.%), cyanidin-3-O-(6”-malonylglucoside)-5-glucoside (15 – 17 mol.%), cyanidin-3-O-(6”-succinylglucoside)-5-glucoside (49 – 56 mol. % ) and cyanidin-3-glucoside (0.3-4.1 mol.%), which corresponds to the literature data, but additionally also isomeric malonated cyanidin-3,5-diglucoside (0.5 – 1.1 mol. % ) and cyanidin-3-O-(6”-malonylglucoside) (3.3 – 6.7 mol.%) were found. The anthocyanin composition of red flowers is formed by similar substituents of anthocyanins, built on a pelargonidinebachbone with a different ratio between the components: pelargonidin-3,5-diglucoside (25 – 36 mol. %), pelargonidin-3-O-(6”-malonylglucoside)-5-glucoside (37 – 47 mol. %), pelargonidin-3-O-(6”-succinylglucoside)-5-glucoside (7 – 31 mol. % ) aa well as two products with unknown malonation position of pelargonidin-3,5-diglucoside (in total up to 5 mol.%). It was found that the stationary phase of Kromasil 100-5C4 is more effective for separation of all components compared to the stationary phase of Symmetry C18 and hydrophilic chromatography withKromasil 60-5DIOL phase.