Bioactive compounds in mucus and shell microstructure of the European ear snail (Radix auricularia)

Radix auricularia is a non-native and invasive freshwater snail species and it may have destructive impacts on biodiversity and ecosystem structure. In recent years, snail mucus, as a sticky substance, has garnered significant attention in the medical and cosmetic industries due to its content of numerous bioactive compounds. Despite frequently being discarded as waste due to the build-up of calcium carbonate crystals through biomineralization, shells of freshwater snail serve multiple functions in aquatic environments and have potential industrial applications. Hence, this study aims to identify bioactive compounds in the mucus and analyze the shell microstructure and mineralogy of the European ear snail (Radix auricularia). Bioactive constituents of mucus were characterized by Gas Chromatography-Mass Spectrometry (GC-FID-MS) analysis. We also conducted analyses on the organic matrix of shells from R. auricularia using X-ray diffraction (XRD) and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS). Our results indicated that ten compounds are characterized by Eicosane (34.16%), 9-Octadecen-1-ol, (Z)-(11.86%) and N,N-Dimetylpalmitamide (5.55%) as the main components of mucus. The antioxidant potential, antifungal and anti-inflammatory properties of Eicosane was in notable quantity in the mucus. In addition, the elemental composition of shell powder comprised of carbon, aluminium, oxygen, calcium, iron, magnesium, silicium, manganese, sodium, sulphur and phosphorus. Aragonite emerged as the dominant mineralogy in the inorganic layer of their shells, as confirmed by XRD. Overall, individual compounds of mucus could be isolated and purified mucus compounds could have applications in pharmaceuticals and health sectors. The shells of R. auricularia offer potential for diverse applications and contribute to environmental sustainability as valuable biomaterials.