Flavonoid differentiation

Kim, H. P. Pham, H. T. Ziboh, V. A., Flavonoids differentially inhibit guinea pig epidermal cytosohc phospholipase A2, Prostagl Leukotr. Essent. Fatty Acids, 2001, 65, 281-286. 

Note The natural fluorescence colors of some flavonoids [7, 9] and anthracene derivatives [16] are altered by the ammonia treatment. This makes possible differentiation on the basis of color. Detection limits per chromatogram zone have been reported of 2 ng for morphine and heroin [2], 6 ng for ochratoxin A [5] and 1 pg for penicillic acid [13]. 

Proanthocyanidins are an important group of di- to oligomeric flavonoids in plants. Four proanthocyanidins (procyanidin B3, prodelphinidin B4, ECG-(4 8)-ECG and GC-(4 8)-EGCG) were determined quantitatively in tea. The amounts in fresh tea leaves were between 1 and 2 g/kg per compound (Nakabayashi, 1991). The occurrence of proanthocyanidins may serve as a criterion for the differentiation between fermented and non-fermented teas (Kiehne et al, 1997). 

Ferreres F, Llorach R and Gil-Izquierdo A. 2004. Characterization of the interglycosidic linkage in di-, tri-, tetra- and pentaglycosylated flavonoids and differentiation of positional isomers by liquid chromatogra-phy/electrospray ionization tandem mass spectrometry. J Mass Spectrom 39(3) 312—321. 

Waridel P, Wolfender J-L, Ndjoko K, Hobby KR, Major HJ and Hostettmann K. 2001. Evaluation of quadrupole time-of-flight tandem mass spectrometry and ion-trap multiple-stage mass spectrometry for the differentiation of C-glycosidic flavonoid isomers. J Chromatogr A 926(1) 29-41. 

Total flavonoid content. Quantitative analysis of flavonoids depends on the objective of the study. Colorimetric estimation of total flavonoid content is measured by the aluminum chloride colorimetric assay (Jia and others 1999 Chang and others 2002). The total flavonoid content measured in this way is normally expressed in equivalent values of a standard flavonoid, often catechin or quercetin equivalents. Not all subgroups of flavonoids can be quantified by colorimetric methods however, total anthocyanin content is determined using the pH-differentiation method (Boyles and others 1993). 

Zabala G, Vodkin L (2003) Cloning of the pleiotropic T locus in soybean and two recessive alleles that differentially affect structure and expression of the encoded flavonoid 3 hydroxylase. Genetics 163 295-309... 

Li, Q.M. and Claeys, M., Characterisation and differentiation of diglycosyl flavonoids by positive ion fast atom bombardment and tandem mass spectrometry, Biol. Mass Spectrom., 23, 406, 1994. 

HMBC, have been developed. Only the last of these has been applied to flavonoids. Recently, a V, /-HMBC experiment has been developed that allowed differentiation between /cH and /cH correlations. ... 

Ma, Y.-L. et al.. Mass spectrometric methods for the characterization and differentiation of isomeric 0-diglycosyl flavonoids, Phytochem. Anal, 12, 159, 2001. 

Franski, R. et al., Differentiation of interglycosidic linkages in permethylated flavonoids from linked-scan mass spectra (B/E), J. Agric. Food Chem., 50, 976, 2002. 

Pikulski, M. and Brodbelt, J.S., Differentiation of flavonoid glycoside isomers by using metal complexation and electrospray ionization mass spectrometry, J. Am. Chem. Soc. Mass Spectrom.,... 

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