The Australian Rainforest Rosewood: From Wood Characteristics to Chemical Profile and Biological Activity of Its Essential Oil

Dysoxylum fraserianum (A.Juss.) Benth. (Meliaceae), commonly known as Australian rosewood, is a rare species endemic to the subtropical rainforests of New South Wales, whose hardwood is used for essential oil (EO) extraction. Despite its commercial relevance, an updated pharmacognostic characterisation of this species is lacking. This study aimed to provide an integrated analysis of the micromorphological, chemical, and biological features of D. fraserianum hardwood and its EO. Anatomical investigations revealed diffuse-porous wood and prismatic calcium oxalate crystals, while histochemical tests showed vessel occlusions with polysaccharide-rich gums, and confirmed the presence of lipophilic extractives within banded axial parenchyma cells. GC–MS and GC-FID analyses identified 52 sesquiterpenes, with ledene (12.74%), β-caryophyllene (8.43%), and δ-cadinene (7.18%) as major constituents, reflecting the chemotaxonomic traits of the Meliaceae family. The EO exhibited concentration-dependent antioxidant and anti-inflammatory activities in multiple in vitro assays and showed moderate antibacterial activity with a bacteriostatic effect against Gram-positive and Gram-negative strains. No fungicidal activity was detected against Candida albicans. These findings confirm the phytochemical uniqueness of D. fraserianum EO and support its biological relevance, offering a modern scientific basis for its potential use in pharmacological and industrial applications.