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Published November 25, 2020 | Version Supplemental Material + Published
Journal Article Open

A Novel Class of Defensive Compounds in Harvestmen: Hydroxy-γ-Lactones from the Phalangiid Egaenus convexus

Creators

  • 1. ROR icon University of Graz
  • 2. ROR icon Medical University of Graz
  • 3. ROR icon Graz University Hospital
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon University of Salzburg

Abstract

When threatened, the harvestman Egaenus convexus (Opiliones: Phalangiidae) ejects a secretion against offenders. The secretion originates from large prosomal scent glands and is mainly composed of two isomers of 4-hydroxy-5-octyl-4,5-dihydro-3H-furan-2-one (1), a β-hydroxy-γ-lactone. The compounds were characterized by GC-MS of their microreaction derivatives, HRMS, and NMR. After the synthesis of all four possible stereoisomers of 1, followed by their separation by chiral-phase GC, the absolute configurations of the lactones in the Egaenus secretion was found to be (4S,5R)-1 (90%) and (4S,5S)-1 (10%). Hydroxy-γ-lactones represent a new class of exocrine defense compounds in harvestmen.

Additional Information

© 2020 American Chemical Society and American Society of Pharmacognosy. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. Received: May 20, 2020; Publication Date: October 16, 2020. This work was supported by the Austrian Science Fund (FWF), project number P29699-B25. We are particularly grateful to P. Föttinger and A. Bauer for their kind assistance in many laborious night excursions to collect specimens of Egaenus convexus and to I. Schäffler for supporting the preparative GC analyses. We thank G. Kunz for providing a photograph of a living specimen of Egaenus convexus. We further thank C. O. Kappe, D. Dallinger, and Y. Chen for their help regarding the initial steps in the synthesis of the β-hydroxy-γ-lactones. Author Contributions: G.R. and F.A. contributed equally to this work. The authors declare no competing financial interest.

Attached Files

Published - acs.jnatprod.0c00277.pdf

Supplemental Material - np0c00277_si_001.pdf

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acs.jnatprod.0c00277.pdf

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Additional details

Identifiers

PMCID
PMC7705963
Eprint ID
106170
Resolver ID
CaltechAUTHORS:20201020-123254097

Funding

FWF Der Wissenschaftsfonds
P29699-B25

Dates

Created
2020-10-20
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field