1998 Volume 64 Issue 5 Pages 826-830
An apocarctenoid, (3R)-galloxanthin, (3R)-10'-apo-β-carotene-3, 10'-diol, (1.1% of total carotenoids) has been isolated and identified from the integuments of wild mature koayu Plecoglossus altivelis. This is the first report of the occurrence of galloxanthin in fish.
Feeding experiments were carried out on young koayu with β-carotene, canthaxanthin, (3R)-β-cryptoxanthin, (3R, 3'R)-astaxanthin, (3S, 3'S)-astaxanthin, (3R, 3'R)-zeaxanthin, lutein A, andfucoxanthin. In the integuments, canthaxanthin and (3R)-β-cryptoxanthin were directly accumulated, but neither β-carotene nor fucoxanthin were accumulated. Lutein A was metabolized to lutein B. (3R)-Gal-loxanthin was produced by eccentric cleavage from (3R, 3'R)-zeaxanthin which is the principal carotenoid in koayu. (3R, 3'R)-Astaxanthin was reductively metabolized to (3S, 3'S)-zeaxanthin and finally converted to a new apocarotenoid (3S)-galloxanthin.