Quality evaluation of Pinellia tuber by LC-TOF/MS targeted to ephedrine

Pinellia tuber (PTE, 半夏, 大半夏, 掌葉半夏, 天南星, 水半夏, 半夏瀉心湯, 半夏厚朴湯, 六君子湯) is derived from the tuber of Pinellia ternata Breitenbach (Araceae), which is a crude drug used in traditional Japanese Kampo medicine for the purpose of antiemesis and expectoration. Since the separation of ephedrine from PTE in 1978, it has been listed as a PTE component in textbooks and internet information. Therefore, there are harmful effects on appropriate use in clinical practice because PTE is dealt with as a crude drug for doping target, and traditional Japanese Kampo medicine containing PTE must be carefully administered to the elderly. However, since the 1978 published report, there has not been any report on the isolation of ephedrine from PTE and the interpretation of biosynthesis remains questionable. In the present study, we analyzed the PTE samples in market distribution products by LC-TOF/MS. From the analysis of the result of ephedrine’s m/z 148.113 [M + H-H₂O]⁺, PTE was not detected (n = 55, detection limit: 0.5 ppb). Additionally, the tuber of P. tripartite (PTR, 大半夏), the tuber of P. pedatisecta (PPE, 掌葉半夏), Arisaema Tuber (ART, 天南星), and the tuber of Typhonium flagelliforme (TFI, 水半夏) that have a similar description to PTE were also not detected. Moreover, the genetic analysis of experimental samples showed that PTE is derived from P. ternata. Furthermore, our attempt to isolate ephedrine from PTE based on the past literature was unsuccessful. These results suggest that PTE in market distribution products may not contain ephedrine as a component.