Incorporation of [1-C-13]1-deoxy-D-xylulose into isoprenoids of the liverwort Conocephalum conicum

• Published in: Phytochemistry (Oxford) Vol. 59; no. 3; pp. 269 - 274
• Main Authors: Thiel, R, Adam, KP
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier 01.02.2002
• Subjects: Biochemistry & Molecular Biology; Biological and medical sciences; Carbon Isotopes; Fundamental and applied biological sciences. Psychology; Life Sciences & Biomedicine; Magnetic Resonance Spectroscopy; Metabolism; Metabolism. Physicochemical requirements; Plant physiology and development; Plant Sciences; Plants - metabolism; Science & Technology; Terpenes - metabolism; Xylulose - analogs & derivatives; Xylulose - metabolism; phytol; PROTEIN; ESCHERICHIA-COLI; TERPENOID BIOSYNTHESIS; [1-C-13]1-deoxy-D-xylulose; Hepaticae; 4-DIPHOSPHOCYTIDYL-2C-METHYL-D-ERYTHRITOL; isopentenyl diphosphate; mevalonic acid pathway; liverwort; HIGHER-PLANTS; CHAMOMILE SESQUITERPENES; 5-PHOSPHATE; cubebanol; methylerythritol phosphate pathway; bornyl acetate; Conocephalum conicum; 1-DEOXY-D-XYLULOSE; MEVALONATE-INDEPENDENT PATHWAY; Terpene; Isotope labelling; Bryophyta; Biosynthesis precursor; Biosynthesis; Metabolic pathway; Isoprenoid
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(01)00453-8

The incorporation of C-13 labeled 1-deoxy-D-xylulose into the monoterpene bornyl acetate, the sesquiterpene cubebanol, and the diterpene phytol has been studied in axenic cultures of the liverwort Conocephalum conicum. Quantitative C-13 NMR spectroscopic analysis of the labeling patterns of the sesquiterpene indicated a possible degradation of 1-deoxy-D-xylulose to acetate and subsequent incorporation via the mevalonic acid pathway. In bornyl acetate, the labeling occurred only in the acetate moiety whereas the isoprene units remained unlabelled. The isoprene units of the diterpene phytol showed incorporation of intact deoxy-D-xylulose. These results indicate the involvement of both IPP biosynthetic pathways and two independently operating compartments/cell types with MEP pathway machinery. One MEP compartment is presumably the plastid where phytol is formed; the second, involved in the build-up of the isoprene part of bornyl acetate, might be located in the oil cells. The acetylation of borneol to bornyl acetate in turn occurs in a cellular compartment that is not involved in the build-up of the isoprene units of borneol. (C) 2002 Published by Elsevier Science Ltd.