Seasonal Variation of Saponin Contents in Platycodon grandiflorum

The balloon flower (Platycodon grandiflorum A. DC) is well known as an ornamental plant and has been used as a vegetable and as a traditional medicinal plant over a long time period.The root parts of Platycodi Radix have rich quantities of saponin glycosides and other important phytochemical constituents.The present study aimed to investigate seasonal variation in saponin contents in P. Radix.Four important saponinsdeapio-platycoside E, platycoside E, platycodin D3, and platyconic acid-were analyzed from the roots of balloon flower collected at different growing times.The contents of all of the analyzed saponins varied significantly with the time of growing.A similar trend of accumulation occurred for deapio-platycoside E and platycoside E. The highest concentrations of these two saponins were observed in August.The accumulation trends of platycodin D3 and platyconic acid in Platycodi Radix differed, in that the largest concentrations of these saponins were observed in May.Our results suggest that the time of harvest should take into consideration the accumulation of particular saponins, and that maximum accumulation of these compounds may occur in May or August.