XANTHOPHYLL

n. yellow pigment found in plants, related to carotene

Xanthophylls (originally phylloxanthins) are yellow pigments from the carotenoid group. Their molecular structure is based on carotenes; contrary to the carotenes, some hydrogen atoms are substituted by hydroxyl groups and/or some pairs of hydrogen atoms are substituted by oxygen atoms. They are found in the leaves of most plants and are synthesized within the plastids. They are involved in photosynthesis along with green chlorophyll, which typically covers up the yellow except in autumn, when the chlorophyll is denatured by the cold.
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Noun
1. yellow carotenoid pigments in plants and animal fats and egg yolks
(synonym) xanthophyl, lutein
(hypernym) carotenoid

n. xanthophyll, yellow pigment found in plants, related to carotene

(n.)
A yellow coloring matter found in yellow autumn leaves, and also produced artificially from chlorophyll; -- formerly called also phylloxanthin.