Ligustrum sinense Lour.: Essential Oil Compositions, Biological Activities, and In Silico Studies-A First Record

The current study first describes the gas chromatography-mass spectrometry (GC-MS) chemical analysis of essential oils from Ligustrum sinense (the family Oleaceae). Linalool (5.0%), cis-phytol (5.1%), methyl salicylate (5.4%), and germacrene B (7.9%) dominated in the twig essential oil. Methyl salicylate (5.5%), linalool (7.4%), and germacrene B (14.2%) were the major compounds in the leaf essential oil, whereas cis-phytol (5.8%), linalool (6.9%), and germacrene B (17.2%) were characteristic compounds in the flower essential oil. L. sinense essential oils (IC₅₀ 208.09-245.39 µg/mL) are comparable to the standard acarbose (IC₅₀ 241.76 µg/mL) in α-glucosidase inhibitory activity. The leaf essential oil (IC₅₀ 4.51 µg/mL) is much better than the standard ascorbic acid (IC₅₀ 13.64 µg/mL) in DPPH radical scavenging. The studied essential oils also exhibited xanthine oxidase inhibitory, anti-inflammatory, protein tyrosine phosphatase 1B inhibitory, and antimicrobial activities. Molecular docking targeting human aldose reductase (PDB ID: 3WY1) revealed strong binding affinities with the major compounds. Germacrene B showed the highest affinity (-6.637 kcal/mol), followed by cis-phytol (-5.729 kcal/mol), forming stable hydrophobic interactions within the enzyme's active site. Toxicity predictions indicated that germacrene B, cis-phytol, and linalool are relatively safe (toxicity class 5).