Exploring the biosynthesis of chemical defenses in harvestmen

• Grant number: 16/17314-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: February 01, 2017
• End date: February 18, 2018
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Anita Jocelyne Marsaioli
• Grantee: Felipe Christoff Wouters
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

In order to defend against natural enemies, harvestmen (Arachnida: Opiliones) present a wide arsenal of strategies, including the production of secretions by specialized glands. In the family Gonyleptidae, these secretions are constituted by vinyl ketones (and their pyranyl ketone dimers), alkylphenols and benzoquinones. However, the biosynthesis of such compounds in arthropods remains relatively unexplored. In particular, the potential involvement of hetero-Diels-Alderases in vinyl ketone dimerization constitutes one of the few described examples of this reaction in biological systems. This project aims to identify the reactions and enzymes responsible for the biosynthesis of those three compound classes in harvestmen, testing the hypothesis that all of them derive from the polyketide pathway. The elucidation of these routes will be achieved by in vitro enzymatic assays, and the possible contribution of symbiont microorganisms will be investigated. Sequencing of the involved enzymes and genes is also proposed. The understanding of chemical defense biosynthesis in harvestmen contributes to studying the evolution of such compounds in arthropods and represents great potential for the application of these enzymes in organic synthesis. (AU)