title: Structures of five new carotenoids from the oyster Crassostrea gigas.
abstract: Five new minor carotenoids, 1-5, were isolated from the oyster Crassostrea gigas. The structure of 1 was determined to be (3S,5R,6R,6'S)-3,5,6'-trihydroxy-3'-oxo-6,7-didehydro-5,6-dihydro-10,11,20-trinor-beta,epsilon-caroten-19',11'-olide 3-acetate by detailed analyses of NMR and CD data. The structures of the other carotenoids, 2-5, were also determined in a similar manner. In the FAB-MS/MS of 2-4, having the 5-hydroxy-3,6-epoxy-5,6-dihydro-beta-carotene moiety, the characteristic product ions resulting from the sequential cleavage of C-C bonds in the polyene chain were observed.
authors.affiliation: Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Maoka
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.forename: N
authors.initials: N
authors.lastname: Akimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000737:chemistry*; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D010125:Ostreidae / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002338:Carotenoids