Biochemical differences between Hypnum cupressiforme and Pseudoscleropodium purum. A case study from across remote sites in Tuscany (central Italy)

Bryophytes are one of the earliest terrestrial plant lineages, yet their biochemical potential remains largely underexplored. Among them, Hypnum cupressiforme and Pseudoscleropodium purum are widespread and ecologically resilient pleurocarpus species that may serve as promising sources of bioactive compounds. This study provides a comprehensive characterization of the two species, investigating the photosynthetic pigments, antioxidant compounds, carbohydrates profiles, and elemental content across five remote sites in Tuscany (Italy). Linear mixed-effects models were used to evaluate the species differences while accounting for site variability. No significant differences were reported for pigment content (i.e., chlorophyll a, chlorophyll b, total chlorophylls, and total carotenoids) and carbohydrate pool (i.e., soluble sugars, pectin, and starch), indicating similar photosynthetic and carbohydrate storage strategies between the two species. Differently, H. cupressiforme showed a higher content of total polyphenols, total flavonoids, and tannins, reaching values similar to or exceeding those found in several medicinal plants, highlighting its strong antioxidant potential. Element analysis showed a higher content of P, S, Ca, and Cu in H. cupressiforme, suggesting species-specific differences in nutrient uptake. Overall, the results indicate that while both mosses share similar physiological pigment and carbohydrate profiles, H. cupressiforme stands out for its enriched antioxidant and mineral composition. These findings support the potential of pleurocarpous mosses, especially H. cupressiforme, as valuable reservoirs of bioactive compounds for future nutraceutical, pharmaceutical, and biotechnological applications.