C-glycosyl flavonoid

C-glycosyl flavonoids than for the corresponding 8-C-glycosyl flavonoids, due to the hydrogen bonds existing between the 2"-hydroxyl of the 6-C-sugar unit and either the 5- or... 

Zhou, B.-N., Blaskd, G., and Cordell, G.A., Iternanthin, a C-glycosylated flavonoid from Alter-nanthera philoxeroides. Phytochemistry, 27, 3633, 1988. 

N Ramarathnam, T Osawa, M Namikii, S Kawakishi. Chemical studies on novel rice hull antioxidants. 2. Identification of isovitexin, a C-glycosyl flavonoid. J Agric Food Chem 37 316-319,1989. 

Z. Bing-nan, B. Gabor, and A. C. Geoffrey, Alternanthin C-glycosylated flavonoid from Alternanthera philoxeroides, Phytochemistry, 27 (1988) 3633-3636. 

Figure 7.10 MS2[M—H] of (a) mono-C-glycosyl flavonoid isomers 8-C-glucosyl luteolin and 6-C-glucosyl luteolin and (b) asymmetric di-C-glycosyl flavone isomers 6-C-arabinosyl-8-C-glucosyl apigenin and 6-C-glucosyl-8-C-arabinosyl apigenin (Ferreres et al., 2003).

In searching for resistance factors in the resistant plants, teosinte and centipede grass, and, in examining the leaves of corn varieties, we conclude that the C-glycosyl flavonoids, typified by maysin, are a major biosynthetic pathway, one which we believe can possibly be genetically amplified to develop com with resistance to both the corn earworm and the fall armyworm. We wish to report on the occurrence of maysin and related compounds in the leaves and silks of corn and discuss possible relationships to com resistance for the corn earworm and the fall armyworm. 

Biosynthesis of C-Glycosyl Flavonoids Biosynthesis of Anthocyanins Systematic Studies with Flavone and Flavonol Glycosides Biological Activity of Flavone and Flavonol Aglycones and Glycosides... 

Oksuz S, Ayyidiz H, Johansson C 1984 6-Methoxylated and c-glycosyl flavonoids from Cen-taurea species. J Nat Prod 47 902- 903... 

Stellaria dichotoma var. lanceolata contains wogonin (flavone derivative), a-spinas-terol, stimast-7-enol, palmitate and furan 3-carboxylic acid, and C-glycosyl-flavonoids. ... 

Figure 3 High-performance reversed-phase chromatography of glycosylated flavonoids and other phenolic compounds with UV absorption (a) navel orange peel (350nm), (b) soybean seeds (270nm), (c) Fuji apple peel (270nm), (d) cranberry (270 nm), (e) Fuji apple peel (520 nm), and (f) cranberry (520 nm). Reproduced from L.-Z. Lin J. M. Harnly, J. Agric. Food...

An example for the separation for flavonoids with HP-RPC is the screening method employed for the systematic identification of glycosylated flavonoids and other phenolic compounds in plant food materials by Lin et al20 These authors used an analytical 4.6 mm x 250 mm 5 pm C18 silica column at 25 °C with linear gradient elution (eluent A (0.1% FA in water and eluent B 0.1% FA in ACN) at 1.0 ml min-1. DAD was performed at 270, 310, 350, and 520 nm to monitor the UV/VIS absorption. The LC system was directly coupled to an ESI mass spectrometer without flow splitting and the mass spectra acquired in the positive and negative ionization mode. The same analytical scheme (aqueous MeOH extraction, reversed-phase liquid chromatographic separation, and diode array and mass spectrometric detection) can be applied to a wide variety of samples and standards and therefore allows the cross-comparison of newly detected compounds in samples with standards and plant materials previously identified in the published literature. 

Harborne compared the behavior of flavonoid glycosides and of several C-glycosyl compounds in a 1 1 solution of ethanol in 2 V hydrochloric acid at 100°, and found that the former are invariably hydrolyzed, whereas the latter are not. Thus, even apigenin 7-D-glucosiduronic acid, which is resistant to acid hydrolysis, is completely cleaved in 4 hours, whereas no C-glycosyl compound tested liberates sugar under these conditions. This procedure provides a convenient method for distinguishing between the two types of compound. 

Truchado P, Vit P, Ferreres F, Tomas-Barberan F (2011) Liquid chromatography-tandem mass spectrometry analysis allows the simultaneous characterization of C-glycosyl and 0-glycosyl flavonoids in stingless bee honeys. J Oiromatogr A 1218 7601-7607... 

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