Canna indica flower: New source of anthocyanins

In this study the red flowers of Canna indica (Cannaceae) were extracted by using sonicator and isolation of anthocyanins have been carried out. Four anthocyanin pigments have been isolated apart from quercetin and lycopene. They are Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl)-β-glucopyranoside (1), Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl)-β-galactopyranoside (2), Cyanidin-3-O-β-glucopyranoside (3) and Cyanidin-O-β-galactopyranoside (4). These compounds were isolated by using HPLC and their structures were subsequently determined on the basis of spectroscopic analyses, i.e., 1H NMR, 13C NMR, HMQC, HMBC, ESI-MS, FTIR, UV–Visible etc. The isolated compounds showed good antioxidant activity thus makes it suitable for use in food coloration and as a nutraceutical. Thus it is a promising pigment source for food applications.

Research highlights
► In this study we have used ultrasound energy for efficient extraction of the colorant from the Canna flowers. Further isolation of anthocyanin from red Canna indica (Cannaceae) has been carried out and four anthocyanin pigments have been isolated apart from quercetin and lycopene. They are Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl-β-glucopyranoside (1), Cyanidin-3-O-(6′′-O-α-rhamnopyranosyl)-β-galactopyranoside (2), Cyanidin-3-O-β-glucopyranoside (3) and Cyanidin-O-β-galactopyranoside (4). These compounds were isolated by using HPLC and their structures were subsequently determined on the basis of spectroscopic analyses, i.e., 1H NMR, 13C NMR, HMQC, HMBC, ESI-MS, FTIR, UV–Visible etc. Extract of the canna flower has substantial amount of antioxidant activity, thus making it suitable for use food coloration. Antioxidant activity of the isolated compounds has been reported.