title: Supercritical fluid CO₂ extraction of Acorus calamus L. (Arales: Araceae) and its contact toxicity to Sitophilus zeamais Motschusky (Coleoptera: Curculionidae).
abstract: Contact toxicities of Acorus calamus L. (Arales: Araceae) extracts obtained from four published extraction methods: soakage, soxhlet, ultrasonic and supercritical fluid CO₂ (SFE-CO₂), were compared in this study. Under the given extraction conditions, SFE-CO₂ extract exhibited the highest contact toxicity against S. zeamais of the four methods. With the SFE-CO₂ method, extraction temperature, pressure, time and the amount of EtOH (the extraction solvent) were identified as having a significant effect on the extract. Orthogonal experiments showed that the optimal extraction parameters were: temperature--55°C, pressure--35 MPa, time--40 min and EtOH--150 mL per 200 g of dry powder. Under these conditions, the yield was 4.12% and the LD₅₀ of the extract against S. zeamais after 96 h of treatment was 27.26 µg cm⁻². β-asarone was the dominant component of the extract derived from the SFE-CO₂ method, accounting for 24.39% of the extract. These results may contribute to the designing of large-scale production processes for obtaining A. calamus extract, which proves to be an effective alternative for the control of stored product insect pests.
authors.affiliation: College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yingjuan
authors.initials: Y
authors.lastname: Yao
authors.forename: Wanlun
authors.initials: W
authors.lastname: Cai
authors.forename: Changju
authors.initials: C
authors.lastname: Yang
authors.forename: Hongxia
authors.initials: H
authors.lastname: Hua
mesh_terms: D029023:Acorus / Q000737:chemistry*; D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D010575:Pesticides / Q000737:chemistry* / Q000494:pharmacology*; D048889:Weevils / Q000187:drug effects*
chemical_list: D010575:Pesticides; D002245:Carbon Dioxide