title: Nuclear magnetic resonance analysis of carotenoids from the burgundy plumage of the Pompadour Cotinga (Xipholena punicea).
abstract: Previous analysis of carotenoids extracted from the burgundy plumage of the Pompadour Cotinga (Xipholena punicea) revealed six novel keto-carotenoid pigments with methoxyl groups in the C3-position of one or both β-rings. High performance liquid chromatography (HPLC), mass spectrometry, chemical analysis and, in some instances (1)H NMR spectroscopy were employed to determine the structures of the molecules. Further analysis by NMR was precluded due to lack of material. The recent acquisition of multiple feathers from X. punicea specimens has made it possible to complete this work using correlated homonuclear spectroscopy (COSY), nuclear overhauser effect spectroscopy (NOESY) and (1)H NMR. These new data conclusively confirm the structures of the six methoxy-carotenoids suggested by the earlier work. In addition, the resonance positions of the protons from the novel 3-methoxy-4-keto-β-ring and 2,3-didehydro-3-methoxy-4-keto-β-ring moieties are reported here for the first time.
authors.affiliation: Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, CT 06269-3060, USA. Electronic address: amy.lafountain@uconn.edu.
authors.forename: Amy M
authors.initials: AM
authors.lastname: LaFountain
authors.forename: Carlos
authors.initials: C
authors.lastname: Pacheco
authors.forename: Richard O
authors.initials: RO
authors.lastname: Prum
authors.forename: Harry A
authors.initials: HA
authors.lastname: Frank
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005241:Feathers / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D046109:Passeriformes
chemical_list: D002338:Carotenoids
keywords: Carotenoid identification; Nuclear magnetic resonance; Plumage pigmentation