Guaiazulene solution
Guaiazulene solution in DMSO with hydroquinone added as an antioxidant

Guaiazulene, also azulon or 1,4-dimethyl-7-isopropylazulene, is a dark blue crystalline hydrocarbon. A derivative of azulene, guaiazulene is a bicyclic sesquiterpene that is a constituent of some essential oils, mainly oil of guaiac and chamomile oil, which also serve as its commercial sources. Various soft corals also contain guaiazulene as a principal pigment.[1] Its low melting point makes guaiazulene difficult to handle, in contrast to the crystalline nature of the parent azulene. The electronic structure (and colors) of guaiazulene and azulene are very similar.

The blue color of the mushroom Lactarius indigo is due to the guaiazulene derivative (7-isopropenyl-4-methylazulen-1-yl)methyl stearate.[2]

Applications

Guaiazulene is an U.S. FDA-approved cosmetic color additive. It – or its 3-sulfonate – is a component of some skin care products together with other skin soothing compounds such as allantoin.[3]

Guaiazulene has applications as a volatile dye with a known evaporation rate to indicate end of use of various products (such as insecticide strips).[citation needed]

References

  1. ^ Bowden, BF; Coll, JC; Tapiolas, DM (1983). "Studies of Australian soft corals. XXX. A novel trisnorsesquiterpene from a Cespitulariaspecies and the isolation of guaiazulene from a small blue Alcyoniumspecies". Australian Journal of Chemistry. 36: 211. doi:10.1071/CH9830211.
  2. ^ Harmon AD, Weisgraber KH, Weiss U.; Weisgraber; Weiss (1979). "Preformed azulene pigments of Lactarius indigo (Schw.) Fries (Russulaceae, Basidiomycetes)". Cellular and Molecular Life Sciences. 36 (1): 54–56. doi:10.1007/BF02003967. ISSN 1420-682X. S2CID 21207966.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ Guarrera, M; Turbino, L; Rebora, A (2001). "The anti-inflammatory activity of azulene". Journal of the European Academy of Dermatology and Venereology. 15 (5): 486–487. doi:10.1046/j.1468-3083.2001.00340.x. PMID 11763400. S2CID 34050487.