Roots of Platycodon grandiflorus A. De Candolle (Campanulaceae), with the bark removed, have been used as food and frequently employed as herbal medicines for inflammatory diseases such as tonsillitis, dermatitis, and cough. Platycodins are the bioactive saponin components of these crude medicines. Recently, P. grandiflorus have been cultivated in Japan and are harvested from October to December according to conventional practices. Seasonal fluctuations in the total saponin content of these roots were determined using LC/MS methods to recommend harvesting times when the saponin content is high. Platycodins A and C are monoacetylated forms of platycodin D; however, the acetyl form is unstable and deacetylates easily. Here, the contents of platycodin D, platycodin D₂, and platyconic acid A were measured as the total saponin content using alkaline hydrolysis for monoacetylated platycodins D, D_2, and platyconic acid A. The results demonstrated that the saponin content in the roots decreased in summer, increased in autumn, but decreased again in late autumn.

Platycodon grandiflorus A. De Candolle (桔梗科) 的根去除了树皮，已被用作食物，并经常用作治疗炎症性疾病如扁桃体炎、皮炎和咳嗽的草药。桔梗甙是这些原料药中的生物活性皂甙成分。最近，P. grandiflorus已在日本栽培，按照常规做法在 10 月至 12 月收获。使用 LC/MS 方法确定这些根的总皂苷含量的季节性波动，以推荐皂苷含量高时的收获时间。Platycodin A 和 C 是桔梗 D 的单乙酰化形式；但是，乙酰基形式不稳定并且容易脱乙酰基。_{此处，通过碱性水解单乙酰化的桔梗素 D、D 2}和桔梗酸 A，测定桔梗素 D、桔梗素 D ₂和桔梗酸 A 的总皂苷含量。结果表明，根中的皂苷含量降低夏季增加，秋季增加，深秋又减少。