Condensed tannins, analysis

SCHOFIELD p, MBUGUA D M and PELL A N (2001) Analysis of condensed tannins a review, Anim Feed Sci Tech, 91, 21-40. 

Sami-Manchado, P. et al.. Analysis and characterization of wine condensed tannins precipitated by proteins used as fining agent in enology. Am. J. Enol. Viticult., 50, 81, 1999. 

Broadhurst RB, Jones WT (1978) Analysis of condensed tannins using acidified vanillin. J Sci... 

The APCI source (Table 2.8) has been used for the analysis of various flavonoids, especially flavonols, flavones, flavanones, and chalcones (Table 2.11). APCI is based on gaseous-phase ionization, and is most suitable for compounds that are partially volatile and have a medium polarity. Thus, the application of APCI with respect to analysis of condensed tannins and anthocyanins is more limited. Compared with ESI, APCI produces more fragment ions in the spectrum due to the harsher vaporization and ionization processes. More information about ESI and APCI can be found in Section 1.4.5. 

Behrens, A. et al., MALDI-TOF mass spectrometry and PSD fragmentation as means for the analysis of condensed tannins in plant leaves and needles, Phytochemistry, 62, 1159, 2003. 

Fulcrand, H. et al., Electrospray contribution to structural analysis of condensed tannin oligomers and polymers, Basic Life Set, 66, 223, 1999. 

Robbins, M.P. et al.. Genetic manipulation of condensed tannins in higher plants. II. Analysis of birdsfoot trefoil plants harboring antisense dihydroflavonol reductase constructs. Plant Physiol, 116, 1133, 1998. 

Fulcrand, H. et al.. Electrospray contribution to structural analysis of condensed tannin oligomers and polymers. In Plant Polyphenols 2. Chemistry, Biology, Pharmacology, Ecology (eds G.G. Gross, R.W. Hemingway, T. Yoshida, and S.J. Branham), Kluwer Academic/Plenum Publisher, New York, 1999, p. 223. 

Laouenan, P. et al., NMR structural investigations and conformational analysis of condensed tannins. A continuing challenge due to restricted rotation about the interflavanyl linkage, Analusis, 25, M29, 1997. 

Singleton and Esau (I) reviewed the methods for phenol analysis of wine. They pointed out that study would be greatly advanced if one could determine the total content of phenolic substances and express it in such a way that analysis of subclasses of phenols could be related to the original total and a balance sheet could be obtained. One could then say, for example, this wine has a total phenolic content of 1200 mg/liter calculated as gallic acid, and of that total, cinnamic acid derivatives account for 200 mg/liter, anthocyanins for 300 mg/liter, other small flavonoids for 200 mg/liter, and condensed tannins complete the total with 500 mg/liter of gallic acid equivalent. To accomplish this, the total phenol analysis not only must meet ordinary criteria of reproducibility and precision, but it also must be based on chemical relationships such that fractions determined separately can be converted to units of the total. Of course when clearcut fractionation can be accomplished by... 

Shadkami, F. Estevez, S. Helleur, R. 2009. Analysis of catechins and condensed tannins by thermally assisted hydrolysis/methylation-GC/MS and by a novel two step methylation. J. Anal. Appl. Pyrolysis 85 54-65. 

PETERS, D.J., CONSTABEL, C.P., Molecular analysis of herbivore-induced condensed tannin synthesis cloning and expression of dihydroflavonol reductase from trembling aspen (Populus tremuloides). Plant J., 2002,32, 701-712. 

Condensed Units Derived from Proanthocyadin Units Biological Activity of Tannins Binding of Tannins to Protein Tannins in the Diets of Animals The Cost of Tannin Defenses and Resource Allocation Other Proposed Functions of Tannins Medicinal Properties of Tannins Correlation of Tannin Consumption and Throat Cancer Tannins and the Production of Leather Other Types of Tannins Analysis of Tannins References... 

The characterization of condensed tannins has been greatly aided by structural and conformational analysis by NMR spectroscopy (Ferreira and Brandt, 1989). Both H-and C-NMR spectroscopy has been used to assign atoms in these complex structures. Fast atom bombardment (FAB) mass-spectral analysis permits observation of the parent ion as well as fragments of these compounds (Barofsky, 1989 Haslam and Lilley, 1986 Okuda et al., 1989a Porter, 1989). 

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