Characterisation of flavonoids in anthurium spathes and their contribution to spathe colouration

Anthurium cultivars are popular worldwide, with flowers having red, pink, coral, white, green, or brown spathes. Anthocyanins are important pigments in the anthurium spathe; however, the presence of other flavonoids has not yet been clarified. Three anthocyanins, seven flavone glycosides, and four flavonol glycosides were characterised using high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS) in the spathe of 25 anthurium cultivars. Correlation analyses and multivariate analyses were then used to explore the relationships between flavonoid composition and spathe colour. The content of anthocyanin cyanidin 3-rutinoside (Cy3R), and the ratio of Cy3R content to pelargonidin 3-rutinoside (Pg3R) content were negatively correlated with spathe lightness (L*), and positively correlated with the chromatic component a*. The value of the chromatic component b* was positively correlated with the contents of several flavonols. This indicated that the anthocyanins Cy3R and Pg3R were the key factors responsible for the red, pink, and purple spathe colours. Flavonols and flavones accounted for the yellow hue of the spathe. This is the first report on flavonoid characterisation in the genus Anthurium using HPLC-ESI-MS. This work will be valuable for elucidating the flavonoid compositions of other anthurium spathes and their effects on the colouration of the spathe.