From Bryophyte to Bioherbicide: Volatilomics and Phytotoxicity Approaches of Corsican Liverwort Diplophyllum albicans

GC-FID, GC-MS, and 1D/2D NMR analyses were performed on the hydrodistilled essential oil, hydrosol, macerate extract, and HS-SPME-derived volatile fraction of Diplophyllum albicans, revealing a chemically diverse sesquiterpenoid profile dependent on the extraction method. A total of 38 compounds were identified. Oxygenated eudesmane lactones, including diplophylline and diplophyllolide, dominated the liquid extracts, whereas the emitted volatile fraction was characterized mainly by hydrocarbon sesquiterpenes Notably, the sesquiterpene lactone 1-acetoxydiplophylline was identified for the first time from a natural source; this study therefore provides its first complete 1H and 13C NMR spectroscopic characterization. The phytotoxic activity of D. albicans essential oil and extracts was evaluated against rice, leek, radish, and watercress using concentration gradients ranging from 250 to 1000 μg/mL. All extracts induced concentration-dependent inhibition of seedling growth with the strongest effects associated with sesquiterpene lactone-rich extracts. These findings highlight D. albicans as a promising source of allelochemicals for sustainable weed management.