Biol. Pharm. Bull. 29(3) 592—594 (2006)

Butylidenephthalide, the components of Angelica acutiloba var. sugiyamae HIKINO (Apiaceae) has the biological activities, such as centrally acting muscle relaxant and antispasmodic effects with characteristic odor. In our previous work, (Z)-butylidenephthalide was isolated as the potent insecticidal compound against adults and larvae of Drosophila melanogaster. Recently, Ahn et al. reported that butylidenephthalide was active constituent of Cnidium officinale against Dermatophagoides farinae and Tyrophagus putrescentiae, and more effective than acaricide, N,N-diethyl-mtoluamide (DEET). Therefore, butylidenephthalide is the potential candidate for new natural pesticide. However, above report was unclear on stereochemistry of butylidenephthalide even though both (E)and (Z)-butylidenephthalide were found from natural resources, and (E)-butylidenephthalide has not been tested against insects and mites. Geometrical stereoselectivity is often crucial on biological activities. Asahina et al. reported that synthetic fluoroquinolone derivatives were tested for antibacterial activity, and (Z)-isomers exhibited 2to 32-fold more potent than corresponding (E)-isomers. Against insects, the importance of geometry was discussed that binding affinity of juvenile hormone carrier protein from the hemolymph of Manduca sexta was decreased as (Z)-double bond are substituted for (E)-double bond in synthetic juvenile hormone analogues. Therefore, evaluation of biological activity for geometrical isomers is required. Biological activity of (E)-butylidenephthalide against insects and mites has not been previously reported. In this paper, we investigated biological activities of (E)-butylidenephthalide against larvae and adults of D. melanogaster, adults of Ctenocephalides felis and two house dust mites, D. farinae and T. putrescentiae, and compared with (Z)-butylidenephthalide to investigate geometrical stereoselectivity. Rotenone (positive control for insecticidal activity) and DEET (positive control for acaricidal activity) were also tested.