Evaluation of the total oxidant scavenging capacity of saponins isolated from Platycodon grandiflorum.

The antioxidant activity of saponins isolated from Platycodon grandiflorum (PG; Balloon flower) was determined using the total oxidant-scavenging capacity (TOSC) assay. Platycodigenin, polygalacic acid, platycodin D, platycoside E and deapioplatycoside E were isolated and their structures were characterised based on their physical and spectral properties and by comparison of these results with similar data in the literature. Platycodin D showed the greatest TOSC value against peroxyl radicals, followed (in decreasing order) by polygalacic acid, platycodigenin, deapioplatycosides E and platycoside E.