Involvement of the mevalonic acid pathway and the glyceraldehyde-pyruvate pathway in terpenoid biosynthesis of the liverworts Ricciocarpos natans and Conocephalum conicum

The incorporation of C-13-labeled glucose into borneol, bornyl acetate, the sesquiterpenes cubebanol and ricciocarpin A, phytol, and stigmasterol has been studied in axenic cultures of the liverworts Ricciocarpos natans and Conocephalum conicum. Quantitative C-13 NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene building blocks of the sesquiterpenes and stigmasterol are built up via the mevalonic acid pathway, whereas the isoprene units of the monoterpenes and the diterpene phytol are exclusively derived from the glyceraldehyde-pyruvate pathway, These results indicate the involvement of both isopentenyl diphosphate biosynthetic pathways in different cellular compartments. (C) 1998 Academic Press.