Valorization of Arnold Fir Seeds and Cones: Composition of Essential Oils, Their Biological Activity and the Potential of Extracts

Essential oils (EOs) of attractive scent from the seeds and cones of Abies × arnoldiana were investigated for the first time, revealing a more than ninefold higher yield from seeds (4.40%) than from cones (0.45%) and distinct terpene profiles. Monoterpene hydrocarbons predominated in both EOs, while the cone oil exhibited greater chemical diversity and a higher proportion of oxygenated monoterpenes (up to 40.9%); the seed oil was characterized mainly by α- and β-pinene, camphene, limonene, as well as bornyl acetate, whereas α- and β-pinene accounted for more than half of the cone EO, with only 38% of constituents shared between the oils. A clear predominance of levorotatory (−) monoterpene enantiomers was observed in both oils; the enantiomeric excess ranged from 88.2% to 100%, and for several compounds, the (+) form was completely absent. Both EOs exhibited bactericidal activity against Staphylococcus aureus and Escherichia coli and cytotoxic effects against normal skin and melanoma cells comparable to thymol, while non-cytotoxic concentrations did not impair collagen biosynthesis in fibroblasts; additionally, seed and cone extracts contained valuable bioactive compounds, including unsaturated fatty acids, tocopherols and phytosterols, highlighting Arnold fir, particularly its seeds, as a promising raw material for cosmetic and other biotechnological applications.