PROGESTERONE: BIOSYNTHESIS FROM PREGNENOLONE IN HOLARRHENA FLORIBUNDA.

After administration of pregnenolone-4-C(14) to Holarrhena floribunda leaves, radioactive progesterone was isolated and purified to constant specific activity by chromatography, conversion to a derivative, and recrystallization. The result suggests that the biogenetic sequence leading to progesterone is the same in plants as in animals.