BREAKDOWN OF INDOLE ALKALOIDS IN SUSPENSION-CULTURES OF TABERNAEMONTANA-DIVARICATA AND CATHARANTHUS-ROSEUS

The relative importance of breakdown on the accumulation of indole alk aloids has been determined in suspension cultures of Tabernaemontana d ivaricata and Catharanthus roseus by the feeding of stable isotope lab elled alkaloids. In all cultures a considerable amount of the alkaloid biosynthesized was broken down. The breakdown was found to be depende nt on the culture period and the half-life was in the order of several days. The breakdown could not explain the difference between producin g and non-producing cultures. Further it was determined that in both c ultures the breakdown was due to both biotic and abiotic factors.