Inhibitor studies of tabersonine metabolism in C. roseus hairy roots

The conversion of tabersonine to lochnericine and hörhammericine was investigated in C. roseus hairy root cultures. The accumulation of lochnericine and hörhammericine, like tabersonine, was associated with growth. Through the use of oxygenase inhibitors, 1-aminobenzotriazole (ABT), clotrimazole (CLOT), and 2.5-pyridinedicarboxylic acid (PCA), details of the metabolic pathway around tabersonine in hairy roots of C. roseus were elucidated. ABT specifically inhibited the formation of hörhammericine, while CLOT inhibited the accumulation of lochnericine. Using jasmonic acid in combination with the inhibitors suggests an inducible P-450 enzyme responsible for the formation of hörhammericine. The inhibitor study also revealed that both lochnericine and hörhammericine are 'turned over' in hairy root cultures.