Chromone

Chromone
Names
	IUPAC name Chromen-4-one
	Preferred IUPAC name 4H-1-Benzopyran-4-one
	Other names 4-Chromone; 1,4-Benzopyrone; 4H-Chromen-4-one; Benzo-gamma-pyrone; 1-Benzopyran-4-one; 4H-Benzo(b)pyran-4-one
Identifiers
CAS Number	491-38-3 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:72013 ;
ChEMBL	ChEMBL13311 ;
ChemSpider	9866 ;
ECHA InfoCard	100.007.035
PubChem CID	10286;
UNII	20C556MJ76 ;
CompTox Dashboard (EPA)	DTXSID40197680 ;
	InChI InChI=1S/C9H6O2/c10-8-5-6-11-9-4-2-1-3-7(8)9/h1-6H Key: OTAFHZMPRISVEM-UHFFFAOYSA-N ; InChI=1/C9H6O2/c10-8-5-6-11-9-4-2-1-3-7(8)9/h1-6H Key: OTAFHZMPRISVEM-UHFFFAOYAY;
	SMILES O=C1C=COc2ccccc12;
Properties
Chemical formula	C9H6O2
Molar mass	146.145 g·mol−1
Acidity (pKa)	-2.0 (of conjugate acid)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Chromone (or 1,4-benzopyrone) is a derivative of benzopyran with a substituted keto group on the pyran ring. It is an isomer of coumarin.

Derivatives of chromone are collectively known as chromones. Most, though not all, chromones are also phenylpropanoids.

Examples

6,7-dimethoxy-2,3-dihydrochromone has been isolated from Sarcolobus globosus.
Eucryphin, a chromone rhamnoside, can be isolated from the bark of Eucryphia cordifolia.^[1]
Cromolyn (disodium cromoglicate) was found to inhibit antigen challenge as well as stress induced symptoms.^[2] Cromoglicate is used as a mast cell stabilizer in allergic rhinitis, asthma and allergic conjunctivitis.
Nedocromil sodium was found to have a somewhat longer half-life than cromolyn; however, production was discontinued in the US in 2008.
Xanthone with a second aromatic ring.

^ Eucryphin, a new chromone rhamnoside from the bark of Eucryphia cordifolia. R. Tschesche, S. Delhvi, S. Sepulveda and E. Breitmaier, Phytochemistry, Volume 18, Issue 5, 1979, pages 867–869, doi:10.1016/0031-9422(79)80032-1
^ HOWELL, J.B. & ALTOUNYAN, R.E. (1967). A double-blind trial of disodium cromoglycate in the treatment of allergic bronchial asthma. Lancet, 2, 539–542. Abstract