Synthesis of β-Methyl Alcohols: Influence of Alkyl Chain Length on Diastereoselectivity and New Attractants of Rhynchophorus ferrugineus

Host plant recognition by two odorant-binding proteins in Rhynchophorus ferrugineus (Coleoptera: Curculionidae)

BACKGROUND

Rhynchophorus ferrugineus, the red palm weevil (RPW), is a key pest that attacks many economically important palm species and that has evolved a sensitive and specific olfactory system to seek palm hosts. Odorant-binding proteins (OBPs) not only play crucial roles in its olfactory perception process but are also important molecular targets for the development of new approaches for pest management.

RESULTS

Analysis of the tissue expression profiles of RferOBP8 and RferOBP11 revealed that these two Rhynchophorus ferrugineus odorant binding proteins (RferOBPs) exhibited high expression in the antennae and showed sexual dimorphism. We analyzed the volatiles of seven host plants by gas chromatography-mass spectrometry and screened 13 potential ligands by molecular docking. The binding affinity of two recombinant OBPs to aggregation pheromones and 13 palm odorants was tested by fluorescence competitive binding assays. The results revealed that eight tested palm volatiles and ferrugineol have high binding affinities with RferOBP8 or RferOBP11. Behavioral trials showed that these eight odor compounds could elicit an attraction response in adult RPW. RNA interference analysis indicated that the reduction in the expression levels of the two RferOBPs led to a decrease in behavioral responses to these volatiles.

CONCLUSION

These results suggest that RferOBP8 and RferOBP11 are involved in mediating the responses of RPW to palm volatiles and to aggregation pheromones and may play important roles in RPW host-seeking. This study also provides a theoretical foundation for the promising application of novel molecular targets in the development of new behavioral interference strategies for RPW management in the future. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Recent advances in the synthesis of insect pheromones: an overview from 2013 to 2022

Covering: 2013 to June 2022Pheromones are usually produced by insects in sub-microgram amounts, which prevents the elucidation of their structures by nuclear magnetic resonance (NMR). Instead, a synthetic reference material is needed to confirm the structure of the natural compounds. In addition, the provision of synthetic pheromones enables large-scale field trials for the development of environmentally friendly pest management tools. Because of these potential applications in pest control, insect pheromones are attractive targets for the development of synthetic procedures and the synthesis of these intraspecific chemical messengers has been at the core of numerous research efforts in the field of pheromone chemistry. The present review is a quick reference guide for the syntheses of insect pheromones published from 2013 to mid-2022, listing the synthesized compounds and highlighting current methodologies in organic synthesis, such as carbon-carbon coupling reactions, organo-transition metal chemistry including ring-closing olefin metathesis, asymmetric epoxidations and dihydroxylations, and enzymatic reactions.