The present experiments have shown that the original specimen of violanin, which was prepared from the violet pansy by Willstätter and Weil
2), was not a mixture in the sense of Karrer and de Meuron
3), but a single substance of sufficient purity. From a series of analytical studies on newly isolated crystalline pigment, it becomes evident that violanin is not a diglycoside, but a complex
triglycoside in which glucose (2mols.), rhamnose (1mol.), and
p-coumaric acid (1mol.) are involved together with delphinidin (1mol.) as essential components. As regards the glycoside structure, it is assumed that in delphinidin the 3-hydroxyl group is occupied by a rhamnoglucosyl residue and the 5-hydroxyl by a glucosyl residue.
p-Coumaric acid may be linked with either of these sugars, amongst which the 3-standing rhamnose is probablefor ester combination.
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