The Madagascar periwinkle Catharanthus roseus contains nearly 200 monoterpenoid
indole alkaloids. It is the source of the chemotherapeutic dimeric alkaloid
vinblastine. Vinblastine is formed when the Iboga-type indole alkaloid catharanthine
is oxidatively coupled to the Aspidosperma-type indole alkaloid vindoline.
Many research groups worldwide have investigated alkaloid formation in C. roseus, such that our understanding of this particular system is relatively
advanced. Success in the isolation of cDNAs encoding both enzymes involved in
the biosynthesis of strictosidine aglycone from primary metabolites and enzymes
involved in the formation of vindoline from tabersonine warrants presentation of
our current comprehension of alkaloid biosynthesis in C. roseus.