Novel Natural Compounds and Their Anatomical Distribution in the Stinging Fireworm Hermodice carunculata (Annelida)

Abstract

Increasing evidence in the field of bioprospection fosters the necessity of studying poorly investigated poisonous marine invertebrates to expand knowledge on animal venom biology. Among marine annelids, amphinomid fireworms are notorious for their bearded trunk equipped with a powerful stinging capacity. Here, a methodological workflow based on analytical chemistry techniques (compound isolation followed by mass spectrometry and spectroscopy analyses) was applied to gain new insights, leading to the identification and structural elucidation of an array of natural products from Mediterranean specimens of Hermodice carunculata. Eight betaine-derived unprecedented compounds, named “carunculines”, were detected, bearing two terminal ammonium groups tri-and disubstituted at the Cα (A, B) and a series of different alkyl chains (I–VIII). The mixture of chemicals was found in all the body parts of H. carunculata, supporting a mechanism of action triggered by their vehiculation inside the dorsal chaetae, and subsequent injection when chaetae break off on contact. Preliminary investigations to understand adaptive features were also performed, showing a trend in carunculine abundance that fits into the evolutionary history of these worms. These findings shed light on the chemical ecology of amphinomids, giving reasons for the success of H. carunculata in benthic environments and providing promising novel metabolites for biotechnological implications.

Highly Concentrated Linear Guanidine Amides from the Marine Sipunculid Phascolosoma granulatum

“…Various hypotheses for the role of phascolosomine ( 7 ) and phascoline ( 8 ) have been formed, with the most recent hypothesis suggesting that they may function as toxins due to their in vivo lethality and negative chronotropic activity. , − However, the true functions of these metabolites remain unknown. The complanines and carunculines have excellent data supporting their role as defensive inflammatory irritants. , The distribution of phascolosomine ( 7 ), phascoline ( 8 ) and the caruculines within their respective organisms has been investigated, and all compounds have been identified at significantly higher concentrations in the viscera tissue. , We therefore investigated the distribution of the new phascolosomines A–F ( 1 – 6 ) within the sipunculid worm to determine their relationship with similar annelid metabolites. Six fresh specimens of P. granulatum were dissected to separate the muscular and viscera tissue.…”

“…The complanines and carunculines have excellent data supporting their role as defensive inflammatory irritants. 16,18 The distribution of phascolosomine (7), phascoline (8) and the caruculines within their respective organisms has been investigated, and all compounds have been identified at significantly higher concentrations in the viscera tissue. 8,18 We therefore investigated the distribution of the new phascolosomines A−F (1−6) within the sipunculid worm to determine their relationship with similar annelid metabolites.…”

“…16,18 The distribution of phascolosomine (7), phascoline (8) and the caruculines within their respective organisms has been investigated, and all compounds have been identified at significantly higher concentrations in the viscera tissue. 8,18 We therefore investigated the distribution of the new phascolosomines A−F (1−6) within the sipunculid worm to determine their relationship with similar annelid metabolites. Six fresh specimens of P. granulatum were dissected to separate the muscular and viscera tissue.…”

Marine natural products

“…629 A mixture of eight amino alcohol-containing betaines were isolated from the stinging fireworm Hermodice carunculata . 630 Although structures of the NPs were presented in the publication, the reliance placed upon LC-MS/MS fragment analysis and NMR spectroscopy of the mixture, means the decision has been made to not show the structures in this review.…”

Effect of temperature and body size on anterior and posterior regeneration in Hermodice carunculata (Polychaeta, Amphinomidae)

“…Moreover, in addition to the need for more extensive research to fully evaluate its impact on hard-bottom marine communities, the bearded reworm is recognized as a hazard to swimmers. Direct contact with human skin can result in painful burns due to the penetrating bristles that inject toxins (Nakaruma et al 2008;Righi et al 2022). This may potentially affect the tourism, impacting local economies in areas where it is very abundant.…”