title: 3-β-Glucosyl-3'-β-quinovosyl zeaxanthin, a novel carotenoid glycoside synthesized by Escherichia coli cells expressing the Pantoea ananatis carotenoid biosynthesis gene cluster.
abstract: Escherichia coli cells that express the full six carotenoid biosynthesis genes (crtE, crtB, crtI, crtY, crtZ, and crtX) of the bacterium Pantoea ananatis have been shown to biosynthesize zeaxanthin 3,3'-β-D-diglucoside. We found that this recombinant E. coli also produced a novel carotenoid glycoside that contained a rare carbohydrate moiety, quinovose (chinovose; 6-deoxy-D-glucose), which was identified as 3-β-glucosyl-3'-β-quinovosyl zeaxanthin by chromatographic and spectroscopic analyses. The chirality of the aglycone of these zeaxanthin glycosides had been shown to be 3R,3'R, in which the hydroxyl groups were formed with the CrtZ enzyme. It was here demonstrated that zeaxanthin synthesized from β-carotene with CrtR or CYP175A1, the other hydroxylase with similar catalytic function to CrtZ, possessed the same stereochemistry. It was also suggested that the singlet oxygen-quenching activity of zeaxanthin 3,3'-β-D-diglucoside, which has a chemical structure close to the new carotenoid glycoside, was superior to that of zeaxanthin.
authors.affiliation: Tongyang Life Science Corp, 729 Eonju-ro, Gangnam-gu, Seoul, 135-995, South Korea.
authors.forename: Seon-Kang
authors.initials: SK
authors.lastname: Choi
authors.forename: Ayako
authors.initials: A
authors.lastname: Osawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Maoka
authors.forename: Jun-Ichiro
authors.initials: J
authors.lastname: Hattan
authors.forename: Kei
authors.initials: K
authors.lastname: Ito
authors.forename: Ai
authors.initials: A
authors.lastname: Uchiyama
authors.forename: Mai
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Shindo
authors.forename: Norihiko
authors.initials: N
authors.lastname: Misawa
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D005810:Multigene Family; D020636:Pantoea / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D024341:Xanthophylls / Q000378:metabolism*
chemical_list: D006027:Glycosides; D011994:Recombinant Proteins; D024341:Xanthophylls; D003847:Deoxyglucose; C037904:6-deoxyglucose