Chemical Composition And Biological Activities Of Zanthoxylum Dimorphophyllum

Essential oil of Zathhoxylum dimorphophyllum was otained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 14 components of the essential oil was identified. The main compounds in the essential oil were a-caryophyllene (29.88%), caryophyllene (22.76%), caryophyllene oxide (22.16%) and isoaromadendrene epoxide (10.28%). The essential oil of Z. dimorphophyllum exhibited strong contact toxicity against the booklice, Liposcelis bostrychophila with a LD50 value of 225.94 pg/cm2. The essential oil also showed fumigant toxicity against L. bostrychophila with a LD50 value of 10.38 mg/L. Moreover, the essential oil also demonstrated strong repellency (Class V) at 4 hrs after exposure against L. bostrychophila at concentrations of 6.4 nL/cm" and above.Based on bioactivity-guided fractionation, five active constituents were isolated and identified from CHC13 fraction of the ethanol extract of Z. dimorphophyllum as toddaculin, coumurrayin, toddanol, toddaculine and skimmianine. Toddaculin showed the strongest larvicidal activity against the fourth instar larvae of Aedes aegypti with a LC50 value of 93.15 μg/mL while coumurrayin, toddanol and toddaculine demonstrated the same level of larvicidal activity against A. aegypti with LC50 values of 153.08μg/mL,161.66 μg/mL and 163.03μg/mL, respectively. Simmianine has a LC50 value of 118.68 μg/ml against the fourth instar larvae of.A. aegypti. Among five constituents, skimmianine possessed the strongest nematicidal activity against Meloidogyne incongnita with a LC50 value of 11.83 μg/mL while toddaculin, coumurrayin, toddanol and toddaculine exhibited nematicidal activity against M. incongnita with LC50 values of 49.72μg/mL,55.85 μg/mL,67.24μg/ml and 122.69 μg/mL, respectively.The results indicated that the essential oil of Z. dimorphophyllum showed fumigant and contact toxicity as well as repellency against the booklice. The five constituent compounds isolated from Z. dimorphophyllum exhibited larvicidal activity against larval mosquito and nematicidal activity against M. incongnita. The above results laid a solid foundation for the further development of botanical pesticides.