Carotenoids in bird plumage - I. The carotenoid pattern in a series of Palearctic Carduelinae

The coloured feathers of Carduelis chloris, Carduelis sinica, Carduelis spinoides, Carduelis carduelis (European and Asiatic), Carduelis spinus, Carduelis citrinella, Serinus serinus and Serinus pusillus were extracted with a new procedure which permits the use of mild conditions (a few minutes at room temperature). After the separation of melanins and proteins, the extracts were analysed by liquid chromatography coupled with mass spectrometry and UV-vis spectroscopy. Two main pigments identified as all trans ε{lunate},ε{lunate}-carotene-3,3′-dione and 3-hydroxy-ε{lunate},ε{lunate}-carotene-3′-one were present in all species, accompanied by several cis isomers. In the plumage of C. chloris, C. sinica and C. spinoides significant amounts of lutein were also detected. In the head plumage of C. carduelis more oxidized ε{lunate},ε{lunate}-carotenoids (C40H52O3 and C40H52O4) were present in all individuals examined.