Preliminary study on metabolite profiling and antioxidant activity of Syzygium vrieseanum (Miq.) Amshoff, a critically endangered species from Indonesia.

This study investigates the chemical composition and medicinal potential of Syzygium vrieseanum (Miq.) Amshoff, a critically endangered species native to Indonesia. Compounds from methanol, ethanol, chloroform, and toluene extracts of leaves and twigs were identified using untargeted Gas Chromatography-Mass Spectrometry (GC-MS). The most abundant compound classes included Alkanes, Carboxylic acids, Ketones, Lactones, Amines, Fatty acids, Terpenes, Aldehydes, and Benzene derivatives. Methanol extracts showed the highest flavonoid and phenol concentrations in leaves (169.80 mg/L and 366.40 mg GAE/g extract, respectively) and twigs (26.60 mg/L and 159.10 mg GAE/g extract, respectively). Antioxidant activity via the DPPH assay showed methanolic and ethanolic leaf extracts as most potent, with IC₅₀ values of 0.138 ± 0.003 and 0.158 ± 0.011 mg/ml, followed by twigs (0.221 ± 0.013 and 0.348 ± 0.025 mg/ml). The results highlight solvent selection for optimising bioactive compound extraction and S. vrieseanum's pharmaceutical potential, offering a biochemical framework for future conservation efforts.