Comparative Phytochemical Profiling of Essential Oils from Selected Abies Species and Analysis of Their Antifungal and Antiradical Activity

<b>Background/Objectives:</b> The essential oils of <i>Abies</i> species possess a complex chemical composition and pronounced biological activity. However, comparative studies of interspecies differences and on the influence of extraction methods on their chemical profile and pharmacological properties are limited. Such data are necessary for identifying the most promising species and optimizing essential oil production technologies for pharmaceutical applications. The aim of this study was to comparatively evaluate the essential oils of seven <i>Abies</i> species obtained by steam distillation and to analyze the effects of three extraction methods on the chemical and biological characteristics of <i>Abies sibirica</i> L. oil. <b>Methods:</b> The essential oils of seven <i>Abies</i> species were isolated by steam distillation. For <i>A. sibirica</i>, supercritical CO₂ extraction and microwave-assisted steam distillation (MASD) were additionally used. Chemical composition was determined by GC-MS. Statistical analysis included ANOVA, PCA and hierarchical cluster modeling, and non-parametric tests. Antifungal activity was assessed against <i>Candida albicans</i>, and antiradical activity was assessed using densitometric analysis. <b>Results:</b> GC-MS analysis revealed significant differences in chemical composition between species and extraction methods. The main compounds were bornyl acetate, α-pinene, and camphene. ANOVA revealed significant differences in bornyl acetate and β-pinene content between species (<i>p</i> < 0.001) and methods (<i>p</i> < 0.01). PCA and clustering identified a bornyl acetate-rich chemotype (<i>A. sibirica</i>, <i>A. grandis</i>, <i>A. lowiana</i>). <i>A. sibirica</i> oil, obtained by MASD, exhibited high antifungal activity (82% inhibition), similar to that of 5-flucytosine (95%). Antiradical activity correlated with monoterpenes corresponding to peaks 2 and 7 of the densitogram. <b>Conclusions:</b> This study demonstrates that the species and extraction method significantly determine the chemical profile and biological properties of <i>Abies</i> oils. <i>A. sibirica</i> oil, obtained by MASD, demonstrated the highest activity, highlighting its potential as a source of biologically active compounds.