Integrating LC-MS/MS and In Silico Methods to Uncover Bioactive Compounds with Lipase Inhibitory Potential in the Antarctic Moss Warnstorfia fontinaliopsis.

Antarctic organisms are known for producing unique secondary metabolites, and this study specifically focuses on the less-explored metabolites of the moss Warnstorfia fontinaliopsis. To evaluate their potential bioactivity, we extracted secondary metabolites using four different solvents and identified significant lipase inhibitory activity in the methanol extract. Non-targeted metabolomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) on this extract predicted the presence of 12 compounds, including several not previously reported in mosses. To gain insights into their enzyme inhibitory activity, the binding affinities of these candidate compounds to lipase were evaluated through in silico molecular docking. Further validation by molecular dynamics (MD) simulations revealed that hyocholic acid and pheophorbide A form stable complexes with human pancreatic lipase (HPL). Based on these results, targeted fractionation experiments were performed, yielding eight fractions. Among these, Fractions 4 and 6, which are assumed to contain those compounds, exhibited higher lipase inhibitory activity compared to the crude extract. Additionally, pharmacokinetic properties of those compounds were analyzed using SwissADME and Molinspiration calculations, suggesting their potential as drug candidates. This study establishes a promising methodology for identifying rare bioactive compounds of low abundance in underexplored natural resources by combining LC-MS/MS analysis with molecular docking. These findings also provide new insights into the chemical ecology of Antarctic mosses and their potential applications in pharmaceutical development.