Identification and Composition of Clasper Scent Gland Components of the Butterfly Heliconius erato and Its Relation to Mimicry. (8th October 2021)

• Record Type: Journal Article
• Authors: Ehlers, Stephanie; Szczerbowski, Daiane; Harig, Tim; Stell, Matthew; Hötling, Susan; Darragh, Kathy; Jiggins, Chris D.; Schulz, Stefan
• Is Part Of: Chembiochem. Volume 22:Number 23(2021)
• Page Start: 3300
• Page End: 3313
• Publication Date: 2021-10-08
• Subjects: biosynthesis -- GC/IR -- pheromones -- terpenoids -- volatile esters; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pharmaceutical chemistry -- Periodicals; 572
• DOI: 10.1002/cbic.202100372
• Languages: English
• ISSNs: 1439-4227

Abstract

Abstract: The butterfly Heliconius erato occurs in various mimetic morphs. The male clasper scent gland releases an anti‐aphrodisiac pheromone and additionally contains a complex mixture of up to 350 components, varying between individuals. In 114 samples of five different mimicry groups and their hybrids 750 different compounds were detected by gas chromatography/mass spectrometry (GC/MS). Many unknown components occurred, which were identified using their mass spectra, gas chromatography/infrared spectroscopy (GC/IR)‐analyses, derivatization, and synthesis. Key compounds proved to be various esters of 3‐oxohexan‐1‐ol and ( Z )‐3‐hexen‐1‐ol with ( S )‐2, 3‐dihydrofarnesoic acid, accompanied by a large variety of other esters with longer terpene acids, fatty acids, and various alcohols. In addition, linear terpenes with up to seven uniformly connected isoprene units occur, e. g. farnesylfarnesol. A large number of the compounds have not been reported before from nature. Discriminant analyses of principal components of the gland contents showed that the iridescent mimicry group differs strongly from the other, mostly also separated, mimicry groups. Comparison with data from other species indicated that Heliconius recruits different biosynthetic pathways in a species‐specific manner for semiochemical formation. Abstract : Scent glands of male Heliconius erato contain up to 350 components with individual compositions. Linear terpenes dominate, either as esters or as long, regular linear isoprene‐oligomers. The high chemical diversity is reflected within the many different mimicry patterns of these butterflies. The compounds were identified by a combination of various methods, including synthesis, which allowed to unravel the underlying biosynthetic pathways used to arrive at these compound bouquets.