The volatile and semi‐volatile constituents of agarwood, the infected heartwood of Aquilaria species: a review

Abstract

A compilation of the volatile and semi-volatile constituents of agarwood, the infected fragrant heartwood of some Aquilaria species, mainly A. malaccensis, A. sinensis and A. crassna, is presented. This high-priced wood has a long tradition in religious ceremonies as incense and its essential oil is well appreciated in fine perfumery. More than 150 compounds have been identified so far, mostly sesquiterpenoids, chromones and volatile aromatic compounds. The scarce knowledge of their organoleptic properties is summarized. Studies on the chemistry of agarwood smoke are discussed. Emphasis is given to structural and analytical aspects.

Classification of Hoi-An and Sin-Chew Agarwood by Components Analysis of VOCs Released in Heat-Treated Agarwood using TD-GCMS and Chemometric Methods

“…Diagnostic sesquiterpenes and other volatile aromatic compounds were used to construct a search library (Naef 2011). Due to isomeric configurations of the 67 sesquiterpenes and 37 simple aromatic compounds reported, there were 42 unique masses in total.…”

“…The number appears in the upper right corner of the compound name in Table 1. The sesquiterpenes and volatile aromatics compounds were identified by their assigned numbers 1 through 66 and 106 through 142 (Naef 2011) and 68* (Chen et al 2012). Table 1 displays the 26 unique target masses detected in 40 agarwood samples.…”

“…Agarwood, the resinous heartwood of the Aquilaria species (Thymelaeaceae) (Naef 2011;Gao et al 2014;Yang et al 2016;Liu et al 2017), is otherwise known as Chen-Xiang, eaglewood, gaharu, jinko, aloeswood, pokok karas, kalamabak, or oud in different cultures (Gao et al 2014;Yang et al 2016). The resin is widely used and well known for its fragrance and applications in aromatherapy, incense, perfume, religions, medicine, etc.…”

“…When agarwood is heated or ignited, it releases volatile organic compounds (VOCs) (Ishihara et al 1993). Chemical analyses of agarwood show that the most abundant compounds in the resin are sesquiterpenes (52%) and 2-(2-phenylethyl) chromone derivatives (41%) (Naef 2011;Lancaster and Espinoza 2012;Mei et al 2013;Jong et al 2014). Most sesquiterpenes possess unique odoriferous properties (Ishihara et al 1993;Yang et al 2016).…”

The economic benefit of agarwood production through aeration method into the Aquilaria malaccensis tree in Bangladesh

“…Agarwood formation is a result of resin synthesis in the xylem tissues of Aquilaria plant. This resin is a chemical substance which consists of aromatic, sesquiterpenes, fatty acids, chromones, phenolic and specially 3-phenyl-2-butanone and alpha-cubebene (Naef, 2011;Hashim et al, 2014). Artificial agarwood or agar oil formation is quite impossible as it is a composition of numerous volatile and semi-volatile compounds.…”