Evaluation of intercellular and extracellular synthesis of biogenic amines by the aquatic moss Vesicularia dubyana

Natural compounds of mosses are an understudied area of phytochemistry. Over the last 20 years, the amount of information on the chemistry of natural compounds in mosses has increased considerably, but is still underwhelming. Historically, only a few hundred natural products have been described for mosses, whereas the potential for bacteria or fungi is measured in hundreds of thousands of metabolites. Although metabolites with antimicrobial, antiviral, fungicidal, and cytotoxic activities have been discovered in mosses, only few studies have been devoted to compounds with neurogenic properties. In our study, the ability of the aquatic moss Vesicularia dubyana to synthesize biogenic amines intercellularly and extracellularly has been evaluated. Aquatic moss was grown in laboratory conditions, and methanol extraction of cell biomass and moss-environment medium was conducted. The presence of biogenic amines was confirmed by UHPLC-MS-MRM analysis. The following compounds were revealed in the cellular biomass of V. dubyana: histamine, kynurenine, kynurenic acid, tryptamine, and tyramine. Histamine was also detected in the moss-environment medium, indicating the extracellular synthesis of this natural compound. Methanol extracts of the studied moss showed low antibacterial and antioxidant activities. Thus, this study for the first time demonstrates biogenic amine synthesis by aquatic mosses.