The cyclic dipeptides, 2,5-diketopiperazines (DKPs), draw attention as bioactive and taste compounds. DKPs, especially those containing Proline (Pro), are contained in heated and fermented foods. Herein, we developed a method for a simultaneous quantitative analysis of Pro-containing DKPs using LC-MS/MS. After optimizing the LC-MS/MS conditions, the developed method was applied to quantify Pro-containing DKPs in Goishi tea, which is a post-fermented tea produced by a two-step aerobic-anaerobic fermentation process. Consequently, 17 kinds of Pro-containing DKPs could be quantified, and the total amount of Pro-containing DKPs was 3.40 mg/L. The recovery in a spiked test was 93 – 117%, which is satisfactory. We believe that the developed method can be used to elucidate the role of Pro-containing DKPs in food.

环状二肽 2,5-二酮哌嗪 (DKP) 作为生物活性和味道化合物而备受关注。DKP，尤其是含有脯氨酸 (Pro) 的 DKP，存在于加热和发酵的食品中。在此，我们开发了一种使用 LC-MS/MS 同时定量分析含 Pro 的 DKP 的方法。优化 LC-MS/MS 条件后，开发的方法用于定量 Goishi 茶中的 Pro 含量 DKP，Goishi 茶是通过两步好氧-厌氧发酵工艺生产的后发酵茶。结果，可定量测定17种含Pro DKP，含Pro DKP总量为3.40 mg/L。加标测试的回收率为 93 – 117%，令人满意。我们相信所开发的方法可用于阐明食品中含 Pro 的 DKP 的作用。