Biosynthesis and Physiology of Opium Alkaloids
Using physiological methods some workers have shown that in Solanaceous plants alkaloids are produced in the germinating roots and translocated to other parts of the plant. A reasonable hypothesis is rapid biosynthesis of the thebaine and conversion to codeine and codeine to morphine followed by rapid conversion of morphine to non-radioactive substances. Such a process would result in the observed daily concentrations of morphine. The amount of alkaloids biosynthesized, however, were very small relative to the amounts involved in the rapid changes for the developing capsule. In contrast, all fractions of the latex were able to metabolize T-morphine in vitro with the 100,000g supernatant showing the highest activity. The biosynthetic pathway for the opium alkaloids in Papaver somniferum has been shown to proceed by the conversion of thebaine to codeinone probably via neopione and migration of the double bond into conjugation.