Animal Carotenoids. 16. Tunaxanthin.

Abstract
Tunaxanthin, first isolated by Hirao and partly characterized by Crozier and Wilkie, may be a common carotenoid of various marine fishes. On the basis of its electronic spectrum, partition ratio, negative epoxide test and formation of a presumed dimethyl ether under conditions for allylic methylation, a structure was assigned to tunaxanthin. Amanses modestus, from Thunnus thynnus and Seriola quinqueradiata were subjected to a modern examination and the carotenoids extracted were discussed.