Guaiazulene
IUPAC name	1,4-dimethyl-7-isopropylazulene
Identifiers
CAS number	489-84-9 Y
SMILES	CC2=C1C(C=C2) =C(C)C=C C(C(C)C)=C1
Properties
Molecular formula	C15H18
Molar mass	198.31 g/mol
Density	0.976 g/cm3
Melting point	31-33 °C
Boiling point	153 °C (7 mm Hg)
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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]

[edit] 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 an anti-ulcer drug, and can be also used as a volatile dye with a known evaporation rate to indicate end of use of various products (such as insecticide strips.)^{[citation needed]}

[edit] References

1. ^ B.F. Bowden, J.C. Coll, and D.M. Tapiolas “Studies of Australian soft corals. XXX. A novel trisnorsesquiterpene from a Cespitularia species and the isolation of guaiazulene from a small blue Alcyonium species” Australian Journal of Chemistry 1983, Volume 36, pages 211 – 214. {{doi:10.1071/CH9830211}}
2. ^ Harmon AD, Weisgraber KH, Weiss U. (1979). "Preformed azulene pigments of Lactarius indigo (Schw.) Fries (Russulaceae, Basidiomycetes)". Cellular and Molecular Life Sciences 36 (1): 54–56. ISSN 1420-682X. 
3. ^ M. Guarrera, L. Turbino, A. Rebora “The Anti-Inflammatory Activity of Azulene” Journal of the European Academy of Dermatology and Venereology, 2001, volume 15, pages 486–487. doi:10.1046/j.1468-3083.2001.00340.x