Cynaroside Explained

Cynaroside (also known as luteoloside) is a flavone, a flavonoid-like chemical compound. It is a 7-O-glucoside of luteolin.

Natural occurrences

It can be found in Ferula varia and F. foetida^[1] in Campanula persicifolia and C. rotundifolia,^[2] in the bamboo Phyllostachys nigra,^[3] and in Teucrium gnaphalodes.^[4]

In foodIt can be found in dandelion (the highest concentration in the flowers,^[5] but also in the roots) and in Cynara scolymus (artichoke).^[6]

Metabolism

Flavone 7-O-beta-glucosyltransferase adds a glucose to luteolin.

A cynaroside 7-O-glucosidase has been identified in the artichoke.^[6]

Spectral data

	UV-Vis^[7]
Lambda-max	UV : 348, 260 nm
Extinction coefficient	(log ε): 4.11, 4.23
	IR
Major absorption bands	? cm^-1
	NMR
	1H-NMR (500 MHz, CD3COCD3 + D2O): δ 3.42 (1H, t, J = 9.0 Hz, H-4′), 3.49 (1H, t, J = 9.0 Hz, H-2″), 3.56 (1H, t, J = 9.0 Hz, H-3″), 3.60 (1H, m, H-5″) , 3.68 (1H, dd, J = 12.2, 5.6 Hz, H-6a″), 3.85 (1H, dd, J = 12.2, 1.8 Hz, H-6b″), 5.10 (1H, d, J = 7.8 Hz, H-1″), 6.44 (1H, d, J = 1.8 Hz, H-6), 6.63 (1H, s, H-3), 6.83 (1H, d, J = 1.8 Hz, H-8), 6.95 (1H, d, J = 8.0 Hz, H-5′), 7.41 (1H, d, J = 8.0 Hz, H-6′), 7.43 (1H, bs, H-2′)
	13C-NMR (125 MHz, CD3COCD3 + D2O): δ 61.7 (C-6″), 70.3 (C-4″), 73.8 (C-2″), 76.8 (C-3″), 77.4 (C-5″), 95.8 (C-8), 100.5 (C-6), 100.7 (C-1″), 103.7 (C-3), 106.3 (C-10), 113.8 (C-2″), 116.5 (C-5′), 120.3 (C-6′), 122.6 (C-1′), 146.3(C-3′), 150.4 (C-4′), 158.0 (C-9), 161.8 (C-5), 163.9 (C-7), 165.8(C-2), 183.1 (C-4)
Other NMR data
	MS
Masses of main fragments	ESI-MS [M+H]+ m/z 449.1

Notes and References

1. 10.1007/BF02254816 . Cynaroside content of the plants Ferula varia and F. Foetida . 1997 . Yuldashev . M. P. . Chemistry of Natural Compounds . 33 . 5 . 597–8. 45802688 .
2. 10.1007/BF00564462 . Cynaroside and luteolin from Campanula persicifolia and C. Rotundifolia . 1972 . Teslov . L. S. . Teslov . S. V. . Chemistry of Natural Compounds . 8 . 117. free .
3. 10.1021/jf0001637 . Evaluation of Antioxidant and Prooxidant Activities of Bamboo Phyllostachys nigra Var. Henonis Leaf Extract in Vitro . 2000 . Hu . Chun . Zhang . Ying . Kitts . David D. . Journal of Agricultural and Food Chemistry . 48 . 8 . 3170–6 . 10956087.
4. Flavonoid Aglycones and Glycosides from Teucrium gnaphalodes. F. A. T. Barberán, M. I. Gil, F. Tomás, F. Ferreres and A. Arques, J. Nat. Prod., 1985, 48 (5), pages 859–860,
5. Web site: Is the Healthiest Part of Dandelion Its Flower? . 17 April 2014 .
6. Purification and Characterization of a Cynaroside 7-O-β-D-Glucosidase from Cynarae scolymi folium . Acta Horticulturae . B . Nüβlein . W . Kreis . 2005 . 681 . 681 . 413–20. 10.17660/ActaHortic.2005.681.58 .
7. 10.1016/j.phytochem.2009.06.006 . Neural cell protective compounds isolated from Phoenix hanceana var. Formosana . 2009 . Lin . Yi-Pei . Chen . Tai-Yuan . Tseng . Hsiang-Wen . Lee . Mei-Hsien . Chen . Shui-Tein . Phytochemistry . 70 . 9 . 1173–81 . 19628235.