Chemical Composition, Anti-tyrosinase Activity and Molecular Docking Studies of Knema malayana Warb. Essential Oil

Abstract

Essential oils produced from aromatic plants denote significant biological activities and are gaining prominence in scientific research. In this study, the chemical composition, anti-tyrosinase activity, and molecular docking studies of Knema malayana Warb. essential oil was investigated. A hydrodistillation method was used to produce the essential oil, characterised by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC/MS). Additionally, anti-tyrosinase activity was evaluated against mushroom tyrosinase, while molecular docking studies were performed with the major components. A total of 38 components (98.9%) were successfully identified in the essential oil, which was characterised by high proportions of δ-cadinene (20.2%), α-cadinol (13.7%), α-amorphene (10.3%), γ-cadinene (6.3%), α-gurjunene (5.3%), γ-gurjunene (5.3%), and α-muurolene (5.0%). The essential oil demonstrated moderate activity towards tyrosinase activity with an IC50 value of 85.3 μg/mL. Consequently, the best docking energy was observed with α-amorphene (-6.9 Kcal/mol), which successfully formed interactions with His263, Phe264, and Val283. These interactions were essential amino acid residues of the tyrosinase receptor.