A study of the carotenoids echinenone and myxoxanthin with special reference to their probable identity

Abstract

The carotenoid myxoxanthin, isolated from mixed Oscillatoria spp., its oxime and its Oppenauer-reduction product (alcohol) are spectro-scopically and chromatographically indistinguishable from echinenone isolated from the blue fresh water alga, Aphanizomenon flos-aquae, and its corresponding derivatives; it is therefore concluded that the pigments are identical. The Oppenauer-reduction product of echinenone is spectrographically and chromatographically identical with cryptoxanthin. This strongly suggests that the structure of cryptoxanthin is 4-hydroxy- and not 3-hydroxy-beta-carotene.