Comparative Lipophilic Phytochemical Profiling and Bioactivity Assessment of Different Organs of Mahonia aquifolium (Pursh) Nutt.: Integrated Analysis of n-Hexane Extracts, Essential Oils and Fatty Acids

Mahonia aquifolium (Pursh) Nutt. is a medicinal plant known for its diverse phytochemical composition; however, information on the lipophilic constituents of its different organs remains limited. This study aimed to characterize the lipophilic composition and associated bioactivities of n-hexane extracts obtained by ultrasound-assisted extraction from leaves, flowers, fruit pulp, and seeds of M. aquifolium. The extracts were analyzed using GC–FID/MS of silylated extracts, FAME–GC, MSD–SPME, and UHPLC–HRMS/MS, and were evaluated for antioxidant and α-amylase inhibitory activities. Nonacosan-10-ol was identified as the predominant constituent in fruit pulp and flower extracts, whereas α-linolenic acid was the major fatty acid in leaves and seeds. Chlorogenic acid was detected as the major phenolic compound in all n-hexane extracts, and 3-hydroxytyrosol was also identified in the lipophilic extracts. The flower extract exhibited notable α-amylase inhibitory activity together with the highest CUPRAC and TEAC values, while the seed extract showed the strongest DPPH radical scavenging activity. The leaf extract demonstrated the highest ORAC value and β-carotene bleaching inhibition. These findings reveal substantial differences in the lipophilic composition and bioactivity profiles among M. aquifolium organs and provide new insights into the valorization of different plant parts as sources of bioactive lipophilic constituents.