Chemical constituents and biological activities against tribolium castaneum (herbst) of the essential oil from citrus wilsonii leaves

Abstract

The essential oil obtained from Citrus wilsonii Tanaka leaves by hydrodistillation was investigated by GC and GC-MS. The main components of the essential oil were identified to be citronellol (16.94%), neryl acetate (10.35%), γ-terpinene (9.85%), citronellal (9.36%) and β-pinene (6.72%). These four compounds, predicted with a bioactivity-test to be the active constituents, were isolated and identified. It was found that the essential oil of C. wilsonii leaves and the isolated compounds possessed fumigant and contact toxicity against Tribolium castaneum adults. The essential oil and γ-terpinene showed strong fumigant toxicity against T. castaneum (LC50 = 8.18 and 4.09 mg L-1, respectively). The repellency of the crude oil and the active compounds was also determined. Citronellol, neryl acetate and β-pinene were strongly repellent (100, 86 and 92%, respectively, at 78.63 nL cm-2 , after 2 h treatment) against T. castaneum. The essential oil and citronellol exhibited the same level of repellency compared with the positive control, N, N-diethyl-meta-toluamide (DEET, N,N-diethyl-3-methylbenzamide). The results indicate that the essential oil of C. wilsonii leaves and its active compounds had the potential to be developed as natural fumigants, insecticides and repellents for the control of T. castaneum.(CC) 2014 SCS. All rights reserved.