Chemical compositions and antioxidant capacities of essential oils from Aquilaria sinensis stem bark / Muhammad Irsyad 'Imaduddin Iskandar

In recent years, Aquilaria essential oil (AEO) has gained much attention due to its potential medicinal properties. Aquilaria, also known as "gaharu,” is a highly sought-after tree species in Southeast Asia, mainly Malaysia and Indonesia, due to its fragrant resin (Agarwood) containing EO. Agarwood is considered a natural treasure and is extensively used in traditional and modern medicines. AEO has many potential medicinal benefits due to its chemical composition. However, source materials from different geographical regions and extraction techniques can produce different chemical compositions in essential oils. This study aims to acquire data on AEO from Sarawak, which is expected to have different chemical compositions and antioxidant capacities due to varying environmental factors. Fresh Aquilaria sinensis stem bark samples that employed a stimulating inoculation method were collected, cut into small pieces, and grinded to a fine powder. The samples underwent hydro-distillation using the Clevenger apparatus to extract essential oils. Gas chromatography-mass spectroscopy (GC-MS) analysis revealed sesquiterpenes as the major chemical group, and 10-epi- γ -eudesmol was one of the major compounds identified in AEO. The EO contained high total phenolic content (1121.04±0.15 mg GAE/g extract) and high total flavonoid content (23.66±10.39 mg QE/g extract), which led to strong antioxidant activities with an IC50 value of 11.37±1.71 μg/mL. The data obtained serves as additional information for commercialising Aquilaria in Sarawak. It is expected to increase farmers' income and contribute to the future technology-based agro-food sector in line with the National Agrofood Policy 2030.