The Biochemistry of Anthocyanins

1. An explanation has been given for the effect of subdued light on the development of anthocyanins. This effect was observed by von Sachs and by Sorby seventy years ago. Nobody has made an exhaustive study of the subject, although Askenasy, Hugo Fischer and others have done work along these lines. 2. When a flavone is reduced to an anthocyanin, as with the Japanese quince, cutting off ultra-violet light prevents the formation of the anthocyanin. 3. When the anthocyanin is formed by the hydrolysis of a leuco-anthocyanin, cutting off of ultraviolet light will not necessarily prevent the formation of the anthocyanin. This occurs with the geranium. 4. We do not know at all approximately how many or which flowers belong to what I call the flavone type and how many or which to the leuco-anthocyanin type. 5. After the biochemistry of the anthocyanins shall have been worked out the botanists and chemists should concentrate on the biochemistry of the carotenes, the lycopenes and chlorophyll.