A Review on Extraction Techniques, Chemical Constituents, and Biological Activities of Acacia dealbata

Native to southeastern Australia, Acacia dealbata (silver wattle) has a rich history of Aboriginal traditional use and modern applications in the perfumery and cosmetic industries. Despite its widespread availability and potential as a source of bioactive compounds, a critical review of its phytochemistry and biological activities is lacking. This article presents a critical review of the scientific literature on A. dealbata to consolidate current knowledge, identify research gaps, and propose future directions based on an analysis of 34 studies covering the chemical composition, extraction techniques, and bioactivities of extracts from the plant. The major chemical classes identified include triterpenes and triterpenoids, glycosides, and phenolics. Extraction solvent and technique have a significant effect on the extraction of bioactive constituents and observed bioactivities. For optimal extraction of phytochemicals, solid–liquid extraction techniques (e.g., Soxhlet, ultrasound, microwave-assisted) with polar solvents showed the best performance. Bioactivity studies consistently reported significant antioxidant and antimicrobial activities, particularly against Gram-positive microorganisms. As a fast-growing, widespread invasive species, A. dealbata has strong potential for valorisation as a source of bioactive compounds and functional ingredients. However, these findings are largely based on preliminary assays, highlighting the need for comprehensive chemical profiling and isolation and characterisation of specific bioactive constituents.