title: Pittosporumxanthins, cycloaddition products of carotenoids with alpha-tocopherol from seeds of Pittosporum tobira.
abstract: A series of carotenoid-alpha-tocopherol cycloaddition products, named pittosporumxanthins B1 ( 3), B2 ( 4), C1 ( 5), C2 ( 6), A3 ( 7), and A4 ( 8), were isolated from the seeds of Pittosporum tobira. The structures were determined to be cycloaddition products of 9' Z-antheraxanthin at the 11' and 12' positions with alpha-tocopherol ( 3 and 4), 9' Z-neoaxanthin with alpha-tocopherol ( 5 and 6), and 9 Z-violaxanthin with alpha-tocopherol ( 7 and 8) on the basis of a detailed analyses of MS and NMR spectroscopic data. The configurations of the carotenoid end groups in the pittosporumxanthins were determined by a modified Mosher's method. Compounds 3, 5, and 7 were assigned (11' R,12' S) and 4, 6, and 8 (11' S,12' R) absolute configurations using CD measurements.
authors.affiliation: Research Institute for Production Development, 15 Shimogamo-morimoto-cho, Sakyo-ku, Kyoto 606-0805, Japan. maoka@mbox.kyoto-inet.or.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Maoka
authors.forename: Naoshige
authors.initials: N
authors.lastname: Akimoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Keiji
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
mesh_terms: D002338:Carotenoids / Q000737:chemistry / Q000302:isolation & purification*; D002942:Circular Dichroism; D007564:Japan; D015394:Molecular Structure; D019685:Rosales / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D013237:Stereoisomerism; D024502:alpha-Tocopherol / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002338:Carotenoids; D024502:alpha-Tocopherol