Тайський уд

Origin

Agarwood forms in the heartwood of Aquilaria trees after they become infected with a type of Phaeoacremonium mould, P. parasitica. The tree defensively secretes a resin to combat the fungal infestation. Aquilaria crassna is one source of agarwood, a resinous heartwood used for perfume and incense. Aquilaria subintegra is a native tree of Thailand and a principal source of agarwood. Thailand has some of the most extensive Aquilaria plantations anywhere. Trat in eastern Thailand has vast plantations of Aquilaria crassna. Aquilaria crassna is critically endangered.

Chemistry

The composition of agarwood oil is exceedingly complex, with more than 150 chemical compounds identified. At least 70 of these are terpenoids, in the form of sesquiterpenes and chromones, and no monoterpenes have been detected at all. Other common classes of compounds include agarofurans, cadinanes, eudesmanes, valencanes and eremophilanes, guaianes, prezizanes and vetispiranes. The exact balance of these materials varies with the age and species of the tree and the details of the oil extraction process. In Aquilaria subintegra oil, sesquiterpenes and their oxygenated derivatives were key components. The aroma of agarwood oil, characterised by intricate, woody and multifaceted notes, originates from specific sesquiterpenes, with agarospirol a notable contributor. Oils containing a diverse range of sesquiterpenes are often considered superior.

Trade and conservation

The aromatic qualities of agarwood vary with the species, the geographic location, the length of time since infection, and the methods of harvesting and processing. Agarwood oil is one of the most expensive essential oils. Adulteration of the wood and oil is common in practice. Bangkok is at the heart of the trade in agarwood and oud oil. Most of the sticks and chips on sale in Bangkok come from Thailand, Cambodia, Vietnam and India. Overharvesting and habitat loss threaten some populations of agarwood-producing species. CITES Appendix II requires that international trade in agarwood be monitored.

—

Related: Agarwood Oil · Agarwood Oud · Australian Oud · Cambodian Oud · Chinese Oud · Indian Oud · Indonesian Oud · Laotian Oud