It has been difficult to evaluate the quality of Angelicae acutilobae Radix (Toki) because of large differences in the contents of its chemical constituents. In this research, we revealed individual differences and localization of (Z)-ligustilide in Toki cultivated and processed under the same conditions. Thirteen Toki samples (dry weight: 68.2 g–132.3 g) were divided and categorized into 13 parts and the (Z)-ligustilide content of each part was quantified. Total (Z)-ligustilide content ranged from 0.08% to 0.22% and the maximum difference between samples was approximately 2.8-fold. In addition, the localization of (Z)-ligustilide was examined. (Z)-Ligustilide content was the highest in lateral root at 0.19%, followed by main root at 0.13%, and the lowest in root head at 0.09%. Furthermore, the content tended to increase as the root became thinner. In particular, the difference in content between the inner side of upper root head (removed 5 mm from the epidermis 0.06%) and the 1.1–3.0 mm in diameter lateral root (0.24%) was largest at approximately 4.1-fold. We revealed that not only differences among individuals but also localization is a factor affecting the quality of Toki. In contrast, individuals with higher root part (main root + lateral root) weight ratio in whole root dry weight had higher (Z)-ligustilide content. The difference in (Z)-ligustilide content among individuals is due to the balance between root head part and root other than head part. It is possible to predict (Z)-ligustilide content from weight ratio of root part to whole root.

由于其化学成分的含量差异很大，一直难以评价当归的质量。在这项研究中，我们揭示了在相同条件下栽培和加工的 Toki中 ( Z )-藁本内酯的个体差异和定位。将 13 个 Toki 样品（干重：68.2 g–132.3 g）分成 13 个部分，并对每个部分的 ( Z )-藁本内酯含量进行量化。总( Z )-藁本内酯含量为0.08%～0.22%，样品间最大差异约为2.8倍。此外，检查了( Z )-藁本内酯的定位。( Z)-藁本内酯含量以侧根最高，为0.19%，主根次之，为0.13%，根头最低，为0.09%。此外，随着根变细，含量趋于增加。特别是上根头内侧（距表皮5 mm 0.06%）与直径1.1-3.0 mm 侧根（0.24%）的含量差异最大，约为4.1 倍。我们发现，不仅个体之间的差异，而且本地化也是影响 Toki 质量的一个因素。相比之下，根部（主根+侧根）重量占全根干重的比例较高的个体具有较高的（Z）-藁本内酯含量。( Z的差异)-藁本内酯含量是由于根头部与根部以外的根部之间的平衡。从根部与全根的重量比可以预测( Z )-藁本内酯含量。