The anthocyanins of the tetraploid blue-black grapes, ‘Pione’, ‘Izunishiki’ and ‘Black Olympia’ were extracted with 1% HCl-methanol, and were purified by the lead acetate method. The individual pigments were separated by thin-layer chromatography. They were identified by their Rf values, molybdate shift and color reactions in the visible and ultra-violet regions. The co-existence of mono- and diglucosides, and the presence of p-coumaric acyl groups were indicated in all cultivars. The pigments in ‘Black Olympia’ consisted of eight anthocyanins as follows: delphinidin-, petunidin-and malvidin-3-monoglucosides, and acylated with p-coumaric acid, and malvidin-3, 5-diglucoside and acylated with p-coumaric acid. ‘Izunishiki’ contained ten anthocyanins, those of ‘Black Olympia’ plus petunidin-and delphinidin-3, 5-diglucosides with p-coumaric acids. ‘Pione’ contained fourteen anthocyanins, the same ten as ‘Izunishiki’ plus cyanidin- and peonidin-3-monoglucosides, and petunidin- and delphinidin-3, 5-diglucosides. The aglycone level pigments, in decreasing order of concentration, were malvidin, delphinidin, petunidin, cyanidin and peonidin, in ‘Pione’.
In ‘Izunishi’ and ‘Black Olympia’, the aglycones were in about the same order, but cyanidin and peonidin were lacking.