Abstract
Hydrangea flower color varies very easily responding to the environmental conditions. To clarify the in vivo mechanism of the blue color development of hydrangea sepals we measured the vacuolar pH and analyzed the organic and inorganic components of colored cells. The mixture of blue and colorless protoplasts, prepared from the blue sepal by the reported procedure, was separated by micro-manipulation to give pure blue protoplasts. By using a micro ODS column (0.3 mm φ) and micro-HPLC system we could quantitatively analyzed the composition of anthocyanin and co-pigments in a single blue cell. We also succeeded in measurement of Al-content by using 50 protoplasts. Delphinidin 3-sambubioside (2) was isolated from blue sepals with major anthocyanin, delphinidin 3-glucoside (1). 2 with 5-caffeoyl quinic acid 3 and Al3+ in acetate buffer (pH 4) gave bluer solution than the mixture of 1, 3 and Al3+.
