Biosynthesis berberine

GALNEDER, E., RUEFFER, M WANNER, G TABATA, M., ZENK, M.H., Alternative final steps in berberine biosynthesis in Coptis japonica cell cultures. Plant Cell Rep., 1988, 7, 1-4. 

AMANN, M., WANNER, G., ZENK, M.H., Intracellular compartmentation of two enzymes of berberine biosynthesis in plant cell cultures. Planta, 1986, 167, 310-320. 

Bock, A., Wanner, G. and Zenk, M.H. (2002) Immunocytological localisation of two enzymes involved in berberine biosynthesis. Planta, 216, 57-63. 

The production of berberine in cell suspension cultures of T. minus was regulated by ethylene via the activation of berberine biosynthesis from (S)-reticuline. However, ethylene promoted the formation of bound polyphenolics that are associated with cell browning when added in the late stage of culture [157]. 

Treatment of cell suspension cultures of T. rugosum with a yeast glucan elicitor induced the production of tyrosine decarboxylase in the late exponential and early stationary growth phases of the cells. Tyrosine decarboxylase has been suggested as the key enzyme between primary and secondary metabolism in the biosynthesis of norlaudanosoline-derived alkaloids, and a good correlation between induced tyrosine decarboxylase activity and berberine biosynthesis has been established [163]. 

Nevertheless in 1985 an oxidase was reported from crude extracts of Coptis japonica cell cultures with different properties as compared to the enzyme from Berberis. This led to a systematic comparison of the two cell cultures concerning the last steps of the berberine biosynthesis. The purified oxidase from... 

M. Rueffer and M.H. Zenk, Berberine synthase, the methylenedioxy group forming enzyme in berberine synthesis. Tetrahedron Lett. 26 (1985), 201-202. E. Galneder, M. Rueffer, G. Wanner, M. Tabata, and M.H. Zenk, Alternative final steps in berberine biosynthesis in Coptis Japonica cell cultures. 

Berberine biosynthesis in Coptis cultures involves formation of a mediylenedioxy bridge into tetrahydrocolum-bamine (73) to yield canadine (74) (Fig. 32.23). TTie pathway differs in Berberis cultures. This should be a warning not to generalize pathways of secondary metabolism unless the enzymatic steps have been elucidated for each species (Hartmann, 1991). ( —)-Canadine (50) was efficiently incorporated into berberine in Hydrastis canadensis (Bhakuni and Jain, 1986). 

Seen together, the transport of berberine in roots and rhizomes of Coptis and Thalictrum is dominated by the activities of transporters at the plasm membrane and the tonoplast. These mechanisms are in contrasting with observations from Berberis, where the transfer of the alkaloid to the vacuole most probably occurs in ER derived vesicles that contain the final enzyme of berberine biosynthesis (Bock et al., 2002). It appears that vesicular transfer is employed in plants that synthesize and store berberine in the same cells, whereas the above berberine carriers serve the intercellular transfer of this alkaloid in plants that established a spatial separation of alkaloid formation and storage (Shitan and Yazaki, 2007). 

Allen RS, Miller JAC, Chitty JA, et al. (2008) Metabolic engineering of morphinan alkaloids by over-expression and RNAi suppression of salutaridinol7-0-acetyltransferase in opium poppy. Plant Biotech J 6 22-30 Allen RS, Millgate AG, Chitty JA, et al. (2004) RNAi-mediated replacement of morphine with the noimarcotic alkaloid reticuline in opium poppy. Nature Biotech 22 1559-1568 AmaimM, Wanner G,ZenkMH (1986) Intracellular compartmentation of two enzymes of berberine biosynthesis in plant cell cultures. Planta 167 310-320... 

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