ABSTRACT
The crude drug Aconite Root (<i>bushi </i>in Japanese) contains toxic compounds called bushi diester alkaloids(BDA), and the raw material with high BDA content has been considered suitable for processing into prepared <i>bushi</i>. Moreover, processing methods and an upper BDA content limit are prescribed in the 16th edition of Japanese Pharmacopoeia. In this study, we closely examined descriptions of high quality <i>bushi </i>in ancient herbal literature, and elucidated the relationship between <i>bushi </i>forms and BDA contents. The results showed that large-sized <i>bushi </i>with enlarged rootlets called “horns” (<i>tsuno </i>in Japanese) were considered higher quality, and the horns and the root tops (<i>hozo </i>in Japanese) were cut off when used as <i>bushi</i>. Meanwhile, chemical studies have shown that larger <i>bushi </i>contains less BDA, and the root tops and the horns contain more BDA than the root body. These results suggest that selecting larger roots and cutting off the more potent parts were processes for reducing BDA. Therefore we conclude that consistently less toxic <i>bushi </i>was considered a higher quality product in ancient times.