Cnicin

Cnicin
IUPAC name [(1R,2S,4E,8Z,10S)-8-(hydroxymethyl)-4-methyl-13-methylidene-12-oxo-11 -oxabicyclo[8.3.0]trideca-4,8-dien-2-yl] (3S)-3,4-dihydroxy-2-methylidene-butanoate
Identifiers
CAS number	24394-09-0 Y
PubChem	5281435
ChemSpider	4444781 Y
ChEMBL	CHEMBL1257707 N
Jmol-3D images	Image 1
SMILES O=C/1O[C@@H]2/C=C(/CC/C=C(/C[C@H](OC(=O)\C(=C)[C@@H](O)CO)[C@H]2C\1=C)C)CO
InChI InChI=1S/C20H26O7/c1-11-5-4-6-14(9-21)8-17-18(13(3)20(25)27-17)16(7-11)26-19(24)12(2)15(23)10-22/h5,8,15-18,21-23H,2-4,6-7,9-10H2,1H3/b11-5+,14-8-/t15-,16-,17+,18+/m0/s1 Y Key: ZTDFZLVUIVPZDU-QGNHJMHWSA-N Y InChI=1/C20H26O7/c1-11-5-4-6-14(9-21)8-17-18(13(3)20(25)27-17)16(7-11)26-19(24)12(2)15(23)10-22/h5,8,15-18,21-23H,2-4,6-7,9-10H2,1H3/b11-5+,14-8-/t15-,16-,17+,18+/m0/s1 Key: ZTDFZLVUIVPZDU-QGNHJMHWBP
Properties
Molecular formula	C20H26O7
Molar mass	378.42 g mol−1
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cnicin is a sesquiterpene lactone, esterified with a substituted acrylic acid, and belonging to the germacranolide class of natural products. It is mainly found in Cnicus (Cnicus benedictus L. (Asteraceae)), and is present in spotted knapweed plants, where highest and lowest concentrations are found in the leaves (0.86-3.86% cnicin) and stems respectively.^[1][2] Cnicin is used as a bitter tonic and the bitterness value is approximately 1,500.

References

1. ^ Olson, B. E. and Kelsey, R. G. (1997). "Effect of Centaurea maculosa on sheep rumen microbial activity and mass in vitro". J. Chem. Ecol. 23 (4): 1131–1144. doi:10.1023/B:JOEC.0000006391.88098.12. 
2. ^ Providing Supplement, with or without PEG, to reduce the effects of cnicin and enhance grazing of spotted knapweed by sheep and cattle, Masters Thesis, M Cheeseman, Montana State University