Metabolomics-based analysis of agarwood from different regions by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

Agarwood is a resinous heartwood valued as both a fragrance and a medicinal resource. Here, agarwood samples from four major producing regions (Hainan, China; Vietnam; Indonesia; and Malaysia) were systematically compared using headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (HS-SPME–GC×GC–TOFMS). Tentative identifications were assigned against NIST 2020 with retention indices (RI) calculated from a C7-C30 n-alkane series. After de-duplication across 12 samples, 1990 non-redundant volatile features were obtained. Hydrocarbons (22.0–36.1%) and alcohols (6.5–15.0%) predominated, followed by aldehydes, ketones and esters. Principal component analysis and OPLS-DA achieved clear origin-based discrimination. Relative odor activity value (ROAV) analysis highlighted vanillin, ( E )-2-nonenal, heptanal, 2-undecanone, 2,3-butanedione and 2-ethylhexanol (ROAV ≥ 1) as key aroma-impact volatiles underpinning sweet, fruity and woody notes. These results establish a volatile–aroma linkage for agarwood and provide a chemical basis for origin authentication, industrial quality grading, and standardization of agarwood-derived ingredients. • Comprehensive characterization of chemical constituents in agarwood from four geographical origins using GC×GC-TOFMS. • Volatile components are linked to flavor profiles using relative odor activity value and sensory radar charts. • Distinct chemotypic variations were evident among agarwoods of different origins.