The major flower anthocyanins of Lobostemon (Boraginaceae)

The chemical basis of flower pigmentation in the genus Lobostemon is presented. Six major anthocyanins were found in the species investigated. Delphinidin-3,5-diglucoside is the most common pigment and tends to be a major component of violet-blue flowers. When the level of delphinidin-3,5- diglucoside is low, then delphinidin-3-glucoside tends to be the major component, together with small amounts of delphinidin-3-rutinoside. Red flowers possess cyanidin-3-rutinoside as a major component. Cyanidin-3,5- diglucoside and cyanidin-3-glucoside occur sporadically in some species, particularly in red or pinkish flowers. The anthocyanins were found to be more or less related to flower colour and only of minor interspecific taxonomic value.