Scopoletin as Key Component of a Novel Acaricidal Agent and Its Production Methodology

Background: A large number of available substances were retained in artemisinin residual materials, and they can be extracted through further separation and purification for further utilization. Methods: Purification and bioguided separation, including silica gel column chromatography (SGCC) and high-pressure liquid chromatography (HPLC), were utilized to isolate scopoletin, an acaricidal compound, from residual materials of Artemisia annua after extraction of artemisinin (RMAAEA). A methanol crude extract was prepared and subjected to chromatographic purification. Results: A total of 20 groups were obtained. The 17th, 8th, and 18th groups showed stronger acaricidal activity against Tetranychus cinnabarinus than other groups. The 17th group was isolated by further HPLC and divided into three parts: 17-1 (16.21%, w/w), 17-2 (5.31%, w/w), and 17-3 (77.64%, w/w). The LC 50 value at 48 h after treatment against T. cinnabarinus was 181.3, 701.1, and 101.5 mg·L −1 . Conclusion: The combined elements of 17-3 after purification was determined as scopoletin. Its industrial process with 900 kg of residual materials finally obtained 1.23 kg of pure scopoletin.