Earthworms from the genus Eisenia express coelomic fluid when
under severe stress. This coelomic fluid contains a complex
mixture of small-molecule metabolites, including aromatic metabolites
which are known to be species-specific, yet their actual identities remain unknown. We have aimed to characterize selected high-concentration coelomic fluid metabolites. The major aromatic compound in Eisenia venetacoelomic fluid is the rare metabolite α-nicotinamide ribo-side; and the major aromatic compound for Eisenia fetida is closely related to the (already characterized) metabolite of Eisenia andrei, which consists of two aromatic quinazoline-2,4-dionering structures linked by N-acetylspermine. The biological function(s) of these metabolites in earthworms is unknown, but we hypothesize that they represent remnants of larger molecules,
possibly bacterial in origin, that are recalcitrant to metabolism by earthworm enzymes.