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Pheromone-binding proteins ( PBPs) play important roles in the information exchange between insect sexes, specifically in the process of transporting fat-soluble odour molecules from the external environment to olfactory receptors through the olfactory sensillum lymph. The PBP functions in this process may explain the sex pheromone identification mechanism used by insects, laying a theoretical foundation for the prevention and control of pests by interfering with olfactory recognition. In the present study, a PBP gene of Cyrtotrachelus buqueti ( Gen Bank accession number: KU845733) is cloned for prokaryotic expression. Using N-phenyl-1-naphthylamine as the fluorescent probe in a competitive binding assay, the ability of CbuqPBP1 to bind 12 sex pheromone analogues and three volatiles of Neosinocalamus affinis shoots is examined. Of the 12 C. buqueti sex pheromone analogues, dibutyl phthalate gives the greatest displacement (inhibitory constant value of 11.1 μ m), whereas the other sex pheromone components show much smaller displacements. Consistent with other PBPs, the three plant volatiles (linalool, benzaldehyde and indole) show only a limited displacement of CbuqPBP1. However, the binding abilities of 1 : 1 ratios of each of the three plant volatiles with dibutyl phthalate show increases of 62.3%, 65.1% and 51.7% over the binding abilities of the three plant volatiles alone. CbuqPBP1 has dual roles in the processes of sensing sex pheromones and plant volatiles. [ABSTRACT FROM AUTHOR]

BACKGROUND To develop a coumarin-based fungicide, a series of 3-benzoyl-4-hydroxylcoumarin derivatives were synthesised and their fungicidal activities were evaluated against typical fungi occurring in Chinese agroecosystems. RESULTS Target compounds were characterised through 1H NMR, 13C NMR and high-resolution mass spectrometry. The crystal structure of compound III-21 was determined through X-ray diffraction. Bioassay results indicated that most of the target compounds showed good growth inhibition against all of the fungi tested in vitro. EC50 of the target compounds against Physalospora piricola, Rhizoctonia cerealis, Sclerotinia sclerotiorum and Botrytis cinerea indicated that most of the target compounds displayed comparable activity with that of carbindazim and chlorothalonil in vitro. Among these compounds, the analogue 3-(2-bromo-4-chlorobenzoyl)-4-hydroxylcoumarin ( III-21) displayed the optimum growth inhibition against R. cerealis (87.5%) and B. cinerea (82.7%) in vivo at 200 µg mL−1 concentration; thus, this analogue is a potential inhibitor of pathogenic fungi and a new major compound for further optimisation. The results of analysing the structure-activity relationships demonstrated that changes in substituents on benzene ring A of 3-benzoyl-4-hydroxylcoumarin caused different fungicidal activities and provided original information on the preferential conformation to maintain high activities. CONCLUSION The present work demonstrated that 3-benzoyl-4-hydroxylcoumarin derivatives can be used as possible major compounds to develop novel fungicides. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]