Anthocyanins in Salix species: A new anthocyanin in salix purpurea bark

Cyanidin 3-glucoside and delphinidin 3-glucoside (minor component) occurred in the bark of Salix purpurea (29 cultivars examined), S. fragilis (3 cvs), S. americana (4 cvs), S. rubra (1 cv.), S. incana (1 cv.), S. aegyptica (1 cv.) and S. alba (3 cvs) and several hybrids. A previously unrecorded anthocyanin was also present in appreciable amounts in the bark of eleven S. purpurea cultivars, notably those with small leaves. In other large-leaved cultivars of S. purpurea (18) it occurred only in traces or was not detected with certainty. A trace was found in one purpurea hybrid, but it was not detected in four others. Small amounts of the new anthocyanin were also found in S. incana (1 cv.), S. fragilis cv. Basfordiana, S. americana cv. Cordata and one hybrid, but were absent from other cultivars of S. fragilis (2) and S. americana (2), and also from S. alba (3), S. aegyptica (1), S. daphnoides (1), S. rubra (1), S. triandra (1), S. viminalis (1) and three hybrids. The new anthocyanin is unique in containing fructose as well as glucose and is based upon a previously undescribed anthocyanidin, possibly dimeric in nature, which is provisionally named purpurinidin.