Deciphering the Absolute Configuration of Murgantiol Isomers in the Pheromone Blend of the Rice Stink Bug, Mormidea v-luteum (Hemiptera, Pentatomidae).

The males-produced pheromone blend of the Mormidea v-luteum (Hemiptera, Pentatomidae) consists in two isomers of zingiberenol (1) and three of murgantiol (2). While the absolute configuration of the zingiberenol isomers has been described, the configurations of the murgantiol isomers remained unexplored. So, our objective was to identify the absolute configuration of the murgantiol isomers (2 a-c) in the pheromone blend. To achieve this, we initially performed dehydration of the natural extract followed by enantiomeric resolution and, as a result, the three isomers was identified as (4R,1'S)-murgantiol. By leveraging the fixed cis and trans relationships among all pheromone components, we established the configuration at C-1 for isomers 2 a and 2 b is S, while that of 2 c is R. Finally, employing microchemical Sharples asymmetric dihydroxylation and epoxide ring closure, we determined the absolute configuration of the epoxide ring. Consequently, the natural isomers 2 a, 2 b, and 2 c were identified as (1S,4R,1'S,4'R)-, (1S,4R,1'S,4'S)-, and (1R,4R,1'S,4'S)-murgantiol, respectively.

Sex pheromone biosynthesis in the sugarcane borer Diatraea saccharalis: paving the way for biotechnological production.

BACKGROUND: The sugarcane borer Diatraea saccharalis (Lepidoptera) is a key pest on sugarcane and other grasses in the Americas. Biological control as well as insecticide treatments are used for pest management, but economic losses are still significant. The use of female sex pheromones for mating disruption or mass trapping in pest management could be established for this species, provided that economical production of pheromone is available. RESULTS: Combining in vivo labelling studies, differential expression analysis of transcriptome data and functional characterisation of insect genes in a yeast expression system, we reveal the biosynthetic pathway and identify the desaturase and reductase enzymes involved in the biosynthesis of the main pheromone component (9Z,11E)-hexadecadienal, and minor components hexadecanal, (9Z)-hexadecenal and (11Z)-hexadecenal. We next demonstrate heterologous production of the corresponding alcohols of the pheromone components, by expressing multiple steps of the biosynthetic pathway in yeast. CONCLUSION: Elucidation of the genetic basis of sex pheromone biosynthesis in D. saccharalis, and heterologous expression in yeast, paves the way for biotechnological production of the pheromone compounds needed for pheromone-based pest management of this species. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Identification and Synthesis of a Macrolide as an Anti-aphrodisiac Pheromone from Males of Heliconius erato phyllis.

Investigation of the contents of the scent glands of the heliconiine butterfly Heliconius erato phyllis via gas chromatography/electroantennography revealed an unprecedented active compound. The males transfer this compound to females during mating. The structure of (2R,6E,10R)-2,6-dimethyl-6-undecen-10-olide, a derivative of geranylacetone, was proposed on the basis of infrared and mass spectrometry spectra and microderivatization and confirmed by racemic and stereoselective syntheses. Bioassays with the synthetic macrolide showed the repellency of this compound, termed phyllisolide, when applied to scent glands of females, identifying it as an anti-aphrodisiac pheromone.