Photochemical UV-Induced Modification of Amber Oil, Enhancing Antimicrobial, Anti-Inflammatory, and Wound Healing Activities with Molecular Docking Insights

Abstract

This study investigated the photochemical transformation of amber oil under UV irradiation and its impact on biological activities. Gas chromatography–mass spectrometry analysis showed that untreated amber oil was rich in long-chain hydrocarbons and fatty acids, predominantly cis-vaccenic acid (36.53%), whereas UV irradiation produced oxygenated compounds, mainly 2-(2-hydroxypropoxy)-1-propanol (13.02%), 1,1′-oxybis-2-propanol (6.93%), and diethyl phthalate (6.73%). UV-treated oil exhibited enhanced antimicrobial activity, particularly against Bacillus subtilis (22 ± 1.0 mm; MIC 15.62 µg/mL) and Candida albicans (24 ± 0.5 mm; MIC 15.62 µg/mL). Strong antibiofilm activity was recorded, exceeding 90% inhibition at 75% MBC against tested bacteria, including Staphylococcus aureus and Escherichia coli. Anti-inflammatory evaluation showed effective inhibition of protein denaturation (IC₅₀ = 2.60 ± 0.11 µg/g). Wound healing assays showed a high closure (90.9%) for UV-treated oil, compared to untreated oil (61.1%). Molecular docking revealed that cis-vaccenic acid exhibited stronger binding affinity toward the target proteins of Aspergillus terreus (4KWD) and B. subtilis (3OIF) than 2-(2-hydroxypropoxy)-1-propanol, with docking scores of −6.64 and −7.12 kcal/mol, respectively. These findings demonstrate that UV-induced photochemical modification is an effective approach to enhance the biological properties of amber oil, providing a basis for its further investigation in natural bioactive product applications.