title: Biosynthesis of anthraquinones in cell cultures of Cinchona 'Robusta' proceeds via the methylerythritol 4-phosphate pathway.
abstract: Robustaquinone B was found as a major anthraquinone in cell cultures of Cinchona 'Robusta' after treatment with a fungal elicitor. Anthraquinones in Cinchona are considered to be of the Rubia type, i.e. rings A and B are derived from chorismate and alpha-ketoglutarate, whereas ring C is formed from isopentenyl diphosphate (IPP). To determine the origin of IPP, either formed via the mevalonic acid pathway or the 2-C-methyl-D-erythritol 4-phosphate pathway, the incorporation of [1-13C]glucose into robustaquinone B was studied. The 13C labeling of robustaquinone B was analyzed by one- and two-dimensional NMR spectroscopy and the labeling pattern was compared with the hypothetical labeling patterns obtained via the different biosynthetic pathways. The results clearly show that the IPP, constituting the ring C of robustaquinone B, is biosynthesized via the 2-C-methyl-D-erythritol 4-phosphate pathway. Moreover, the data also confirm that rings A and B of robustaquinone B are formed from chorismate and alpha-ketoglutarate via o-succinylbenzoate.
authors.affiliation: Division of Pharmacognosy, Leiden / Amsterdam Center for Drug Research, Gorlaeus Laboratories, PO Box 9502, 2300 RA, Leiden, The Netherlands.
authors.forename: Ying Shan
authors.initials: YS
authors.lastname: Han
authors.forename: Robert van der
authors.initials: Rv
authors.lastname: Heijden
authors.forename: Alfons W M
authors.initials: AW
authors.lastname: Lefeber
authors.forename: Cornelis
authors.initials: C
authors.lastname: Erkelens
authors.forename: Robert
authors.initials: R
authors.lastname: Verpoorte
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000378:metabolism*; D002478:Cells, Cultured; D002929:Cinchona / Q000166:cytology / Q000378:metabolism*; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism*; D045782:Hemiterpenes; D009943:Organophosphorus Compounds / Q000737:chemistry; D013403:Sugar Phosphates / Q000378:metabolism*
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D000880:Anthraquinones; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D013403:Sugar Phosphates; C450161:robustaquinone B; C004809:isopentenyl pyrophosphate; D004896:Erythritol