Inhibitory tannins

LONGSTAFF M, MCNAB J M (1991) The inhibitory effects of hull polysaccharides and tannins of field beans (Vida faba L.) on the digestion of amino acids, starch and hpid and on digestive enzyme activities in young chicks. Br. TNutr. 65 199-216. 

Contradictory opinions have been referred to in the literature particularly on the nature of the iron-tarmate and its interaction with the rusted steel due to the diversity of the material used in different studies. Studies have included the use of tannic acid [7-10], gallic acid [11], oak tannin [12, 13], pine tannin [14] and mimosa tannin [15]. In order to establish the correlation between the ferric-taimate formation and the low inhibition efficiency observed at high pH from the electrochemical studies, phase transformations of pre-rusted steels in the presence of tannins were evaluated. In this work the quantum chemical calculations are conducted to analyse the relationship between the molecular stracture and properties of ferric-taimate complex and its inhibitory mechanism. 

Wall ME, Wani MC, Brown DM, et al., Effects of tannins on screening of plant extracts for en2yme inhibitory activity and techniques for their removal. Phytomedicine 5-.2% —2%5, 1996. 

Hatano, T. et al., Effects of interactions of tannins with co-existing substances. VII. Inhibitory effects of tannins and related polyphenols on xanthine oxidase, Chem. Pharm. Bull., 38, 1224, 1990. 

Another major problem associated with the extraction of DNA from archaeological specimens is that the procedure often co-extracts impurities that can later complicate, or prevent, the study of the extracted DNA by inhibiting PCR amplification (reviewed by 5). Commonly encountered inhibitory substances found in aDNA extracted from teeth, bones, mummified tissue, and coprolites include humic acids, ftilvic acids, tannins, porphyrin products, phenolic compounds, hematin, and collagen type I (37—42). The formation of Maillard products, commonly encountered in coprolite samples, can also prevent PCR amplification by causing DNA to become inaccessibly trapped in these sugar-derived condensation products (12). As the negative results in many aDNA studies are attributed to the presence of PCR inhibitors, our extraction method outlined below pays particular attention to the problem and offers a simple test for the presence of PCR inhibitors in DNA extracts. 

McAllister TA, Martinez T, Bae FID, Muir AD, Yanke LJ, Jones GA. 2005. Characterization of condensed tannins purified from legume forages Chromophore production, protein precipitation, and inhibitory effects on cellulose digestion. J Chem Ecol 31 2049-2068. 

Feeny, P.P., Inhibitory effect of oak leaf tannins on the hydrolysis of proteins by trypsin, Phytochemistry, 8, 2119, 1969. 

Green, F. B. and Corcoran, M. R. 1975. Inhibitory action of five tannins on growth induced by several gibberellins. Plant Physiol. 56, 801-806... 

Kandra, L., Gyemant, G., Zajacz, A., Batta, G. (2004). Inhibitory effects of tannin on human salivary alpha-amylase. Biochem. Bioph. Res. Comm., 319, 1265-1271. 

H. Kakegawa, H. Matsumoto, K. Endo, T. Satoh, G. Nonaka, and I. Nishioka. Inhibitory effects of tannins on hyaluronidase activation and on the degranulation from rat mesentery mast cells. Chem. Pharm. Bull. 33 5079 (1985). 

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