Stereochemistry of two pheromonal components of the bumblebee wax moth, Aphomia sociella

Erika A Wallin,Jiří Kindl,Erik Hedenström,Irena Valterová,Blanka Kalinová

doi:10.1038/s41598-020-59069-1

Abstract

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees. In this species, males produce sexual pheromone to attract females, while females produce an aphrodisiac pheromone that initiates male courtship. Both pheromones contain 6,10,14-trimethylpentadecan-2-one (TMPD-one) and the corresponding alcohol, 6,10,14-trimethylpentadecan-2-ol (TMPD-ol) in sex specific quantities. Male sex pheromone consists of 7 components with TMPD-one as a minor one and traces of TMPD-ol. In female aphrodisiac pheromone, TMPD-ol is the major component, while TMPD-one is present in traces. Here we report on the absolute configuration of TMPD-one in male sex pheromone and TMPD-ol in female aphrodisiac pheromone of A. sociella. The configuration was determined from GC/MS of prepared (S)-acetoxypropionyl esters of TMPD-ol. TMPD-one was first reduced to the alcohol that was then derivatized with (S)-acetoxypropionyl chloride. The GC/MS data of obtained diastereoisomers were compared with synthetic standards. The absolute configuration of TMPD-one in the male pheromone was (6R,10R). The configuration of TMPD-ol in the female pheromone was (2R,6R,10R). Electrophysiological experiments showed that TMPD-one and TMPD-ol are perceived by both sexes. The synthetic standards of naturally produced stereoisomers elicited higher responses than mixtures of all stereoisomers.

Highlights

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees
gas chromatography (GC)/MS has been previously used to determine the stereoisomeric composition of TMPD-ol and TMPD-one in wing extracts of Bicyclus butterfly species[10], stereoisomeric composition of TMPD-one in Euglossa bees[11] and of 3,7-dimethylpentadecan-2-ol in female extracts of pine sawflies[14], where the stereoisomers of the chiral alcohols were separated as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters
TMPD-one and TMPD-ol were found in both sexes, but their ratio in the sexes differed

Summary

Introduction

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees In this species, males produce sexual pheromone to attract females, while females produce an aphrodisiac pheromone that initiates male courtship. We report on the absolute configuration of TMPD-one in male sex pheromone and TMPD-ol in female aphrodisiac pheromone of A. sociella. TMPD-ol plays a role in the communication of another species of this family, Corcyra cephalonica, where females utilize TMPD-ol for attracting males[8] Both TMPD-one and TMPD-ol are chiral compounds, but in none Galleriinae species, the absolute configuration has been reported. We present the stereochemistry of TMPD-one in male sex pheromone and TMPD-ol in female aphrodisiac pheromone of A. sociella as well as the electroantennographic activity of these compounds. We show for the first time that males produce minute amount of TMPD-ol and that female antennae respond to this compound

Methods

Results

Conclusion