Metabolism of carotenoids in the apple snail, Pomacea canaliculata

Feeding experiments with beta,beta-carotene, canthaxanthin, (3R,3'R)-zeaxanthin, (3R,3'R,6'R)-lutein and racemic astaxanthin on the apple snail Pomacea canaliculata were investigated. Based on the experimental results, beta,beta-carotene was oxidatively metabolized, and the resulting principal metabolic product (3S,3'S)-astaxanthin along with other keto carotenoids such as (3S)-3-hydroxy-beta-echinenone, canthaxanthin, (3S,3'R)-4-ketozeaxanthin and (SS)-phoenicoxanthin was accumulated in the gonad. Similarly, (3R,3'R,6'R)-lutein was converted into fritschiellaxanthin [(3S,3'R,6'R)-3,3'-dihydroxy-beta, epsilon-caroten-4-one]. It was concluded that P. canaliculata had the ability to oxidize the C-3, 4 positions on the beta-end group. (C) 1997 Elsevier Science Inc.