Quassin
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 464378137
| Name = Quassin
| ImageFile = Quassin test ACS.png
| ImageSize =
| ImageName = (+)-Quassin
| IUPACName = 2,12-Dimethoxypicrasa-2,12-diene-1,11,16-trione
| SystematicName = (3aR,3a1S,6aR,7aS,8S,11aS,11bS)-2,10-Dimethoxy-3,3a1,8,11a-tetramethyl-3a,3a1,6a,7,7a,8,11a,11b-octahydrophenanthro[10,1-bc]pyran-1,5,11(4H)-trione
| OtherNames =
|Section1={{Chembox Identifiers
| EINECS = 200-985-9
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 59014
| InChI1 = 1/C22H28O6/c1-10-7-14(26-5)20(25)22(4)12(10)8-15-21(3)13(9-16(23)28-15)11(2)18(27-6)17(24)19(21)22/h7,10,12-13,15,19H,8-9H2,1-6H3/t10-,12+,13+,15-,19+,21-,22+/m1/s1
| InChIKey1 = IOSXSVZRTUWBHC-LBTVDEKVBB
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}= {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C22H28O6/c1-10-7-14(26-5)20(25)22(4)12(10)8-15-21(3)13(9-16(23)28-15)11(2)18(27-6)17(24)19(21)22/h7,10,12-13,15,19H,8-9H2,1-6H3/t10-,12+,13+,15-,19+,21-,22+/m1/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}= {{stdinchicite|correct|chemspider}}
| StdInChIKey = IOSXSVZRTUWBHC-LBTVDEKVSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 76-78-8
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = QP1YAK6QGK
| PubChem = 65571
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 517016
| SMILES = O=C1C(\OC)=C/[C@@H](C)[C@H]4[C@]1([C@H]3C(=O)C(\OC)=C(/[C@@H]2CC(=O)O[C@@H]([C@@]23C)C4)C)C
| InChIKey = IOSXSVZRTUWBHC-LBTVDEKVBB
}}
|Section2={{Chembox Properties
| C=22 | H=28 | O=6
| Appearance = White crystalline substance
| MeltingPtC = 200 to 222
| MeltingPt_notes =
| BoilingPtC = 586
| Solubility = Insoluble
| VaporPressure = 13 mmHg (@25 °C)
}}
}}
Quassin is a white, bitter, crystalline substance that is the prototypical example of the family of quassinoids. It can be extracted from the quassia tree, from which it gets its name. It was first isolated in 1937,E.P. Clark, J. Amer. Chem. Soc. (1937) and its chemical structure was elucidated in 1961.{{cite journal |last1=Valenta |first1=Z. |last2=Papadopoulos |first2=S. |last3=Podešva |first3=C. |title=Quassin and Neoquassin |journal=Tetrahedron |date=1961 |volume=15 |issue=1–4 |pages=100–110 |doi=10.1016/0040-4020(61)80013-6}}
It is one of the most bitter substances found in nature, with a bitter threshold of 0.08 ppm and it is 50 times more bitter than quinine.Scientific Committee on Food [http://ec.europa.eu/food/fs/sc/scf/out134_en.pdf Opinion of the Scientific Committee on Food on quassin (expressed on 2 July 2002).] {{webarchive|url=https://web.archive.org/web/20110519191751/http://ec.europa.eu/food/fs/sc/scf/out134_en.pdf |date=19 May 2011 }} SCF/CS/FLAV/FLAVOUR/29 Final
Extracts of the bitterwood tree (Quassia amara) containing quassin are used as additives in soft drinks.
Although its skeleton possesses 20 carbon atoms, quassin is not a diterpene but rather a triterpene lactone, which derives from euphol by loss of 10 carbon atoms including C4.