Flavonols from glycosides

Cuyckens F, Shahat AA, Van den Heuvel H, Abdel-Shafeek KA, El-Messiry MM, Seif-El Nasr MM, Pieters L, Vlietinck AJ and Claeys M. 2003. The application of liquid chromatography-electrospray ionization mass spectrometry and collision-induced dissociation in the structural characterization of acylated flavonol O-glycosides from the seeds of Carrichtera annua. Eur J Mass Spectrom 9(4) 409-420. 

Flavonol galloyl-glycosides from Hyperprep ODS CH3CN-H2O, gradient 25... 

Abe, F. et al., Flavonol sinapoyl glycosides from leaves of Thevetiaperuviana. Phytochemistry, 40, 577, 1995. 

Glycosides of flavonols from onions, such as quercetin-4 -0-glucoside and quercetin-3 -0-methyl-4 -0-glucoside, have been found in the plasma of volunteers with a peak of absorption of 0.5 - 4 h [64]. 

Kiehne and Engelhardt (283) developed HPLC-MS with thermospray interface (ammonium acetate solution for buffer ionization) to determine flavonols, flavonol 0-glycoside, flavone C-glycosides, CF, TB, theogalline, and theanine from green tea. 

Han, Y., Nishibe, S., Noguchi, Y. and Zhexiong, J. (2001) Flavonol glycosides from glycosides from the stems of Trigonella foenum graecum. Phytochemistry 49, p.11 53. 

Procyanidins with different degrees of polymerization such as dimers, trimers, and polymers from extracts of different natural sources were found to be nonmutagenic in the Salmonella mutagenesis assay. Moreover, the mutagenic impurity in procyanidin B-4 was isolated by reversed-phase high-performance liquid chromatography (HPLC). Procyanidin B-4 was identified as rutin (flavonol O-glycoside, 3) (Fig. 22) [55]. 

Not all flavonoids are capable of yielding alkali adducts. Thus, flavonol-3-0-glycosides generate sodium or potassium adducts. By contrast, these adducts are not obtained from flavonol-4 -( -glycosides and flavone glycosides. 

An examination of the flavonoids of Villarsia (Bohm et al., 1986) revealed a heterogeneous array of flavonol glycosides, based upon kaempferol, quercetin, and isorhamnetin, with each species exhibiting a unique assortment. Surprisingly, there were greater similarities between the pigment profile of V capensis and species from eastern Australia, V exaltata (Soland. ex Sims) G. Don from Tasmania and V. reniformis R. Br. from New South Wales, than with species native to... 

A detailed study of the flavonoid chemistry of the island endemics, the closely related G. tinctoria, and live additional species from the mainland provided additional evidence pointing toward G. tinctoria as the ancestral species (Pacheco et al., 1993). The flavonoid profiles of all species consisted of flavonol glycosides as major components with an unidentified flavone glycoside and several unidentified phenolic compounds (presumably not flavonoids). The pattern of distribution of the flavonol glycosides and unidentified flavones within the set of nine species proved to be extremely informative. (The phenols were ubiquitous and are not considered further.) Kaempferol glycosides were seen in neither the island species nor G. tinctoria, but were present, in several combinations, in the rest of the mainland taxa. The isorhamnetin glycosides showed the reverse pattern, with one exception the island endemics and G. tinctoria exhibited these compounds, whereas four of the other mainland species did not. The sole exception is G. boliviari, which exhibited one of the isorhamnetin derivatives. 

Table 6.3 Flavonol glycoside profiles of Juan Fernandez Islands species of Gunnera compared to species from South America and Mexico (from Pacheco et al., 1993)...

As relatively few standard compounds are available from commercial or other sources, identification of flavonol glycosides has to be achieved by alternative means, for example UV-, H- and C-NMR spectroscopy. Therefore hydrolysing all glycosides to aglycones followed by HPLC determination offers a practical method for the quantitative determination of flavonoids in tea (Hertog et al, 1993a Wang and Helliwell, 2001). 

PRICE K R, RHODES M j c and BARNES K A (1998) Flavonol glycoside content and composition of tea infusions made from commercially available teas and tea products , J Agric Food Chem, 46, 2517-22. 

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