Phenols tannins

Developments in glued laminated structures and panel products such as plywood and chipboard raises the question of the durability of adhesives as well as wood. Urea-formaldehyde adhesives are most commonly used for indoor components. For exterior use, resorcinol adhesives are used for assembly work, whilst phenolic, tannin and melamine/urea adhesives are used for manufactured wood products. Urea and casein adhesives can give good outdoor service if protected with well-maintained surface finishes. Assembly failures of adhesives caused by exudates from some timber species can be avoided by freshly sanding the surfaces before glue application. 

Chemical analyses and fractionations. Freeze-dehydrated cotton tissue was analyzed for condensed tannin (heated n-BuOH-HCl), gossypol (phlorogluclnol-HCl), and anthocyanlns-anthocyanldlns (ale. HCl at 540 nm). Other analyses performed but not reported here were for catechin, total phenols, (tannin), and aniline reactive terpenes (gossypol). 

N.A. Triterpenoid saponins, flavonoids, phenols, tannins, volatile oil. Internally for bronchitis, respiratory tract infections, insomnia, anxiety, rheumatic disorders. 

Table XIII. Total Phenol, Tannin, and Non tannin Content of Wines From the Data of Mitjavila et al. (37)...

H NMR data from these seven sites are presented by spectral peak-height ratios in Table III. The sites were listed in order of increasing aromatic plus olefinic carbon percentages. Fulvic acids from all the lake samples are much lower in aromatic plus oleflnic carbon content than those from river samples. These results confirm the hypothesis that autothonous inputs result in dissolved humic substances that have a low aromatic plus oleflnic carbon content. The lake samples also are lower in the ratios of peak 2 (carboxylated chains and aliphatic ketones), peak 3 (carbohydrates), and peak 4 (phenolic tannins and lignins) to peak 1 (branched methyl groups and alicyclic ali-phatics) than are the river samples. 

We use 5 mM L-histidine monohydrochloride (pH 7.0) as a homogenization buffer. For plant tissues containing secondary metabolites that can inhibit enzyme activity (e.g., resins, phenolics, tannins), complex extraction buffers are usually required.11 14,17 Examples of extraction buffers for... 

Many deciduous and coniferous trees contain varying levels of phenolics, including tannins. Blackwater rivers in forested areas of the world, such as the Amazon basin or the southern United States, carry phenolics (tannins) leached out of trees. Such rivers differ in plant and animal life from whitewater rivers. ... 

Discoloration and/or precipitation occur with various substances, especially phenols, tannins, tars, and tarlike materials. The antimicrobial activity of paraben preservatives is reduced in the presence of polysorbates. See Methylparaben. 

To determine the effects of the constituents in the culture medium on phenolic (tannin) production in G. thunbergii hairy roots, two culture media were prepared one consisted of 1/2 MS major and minor elements (inorganic elements) and B5 vitamins (named as "1/2 MS vB5") and the other B5 major and minor elements and MS vitamins (B5 vMS). The hairy roots (ca 70 mg, fw) subcultured in 1/2 MS and B5 liquid media, respectively, were inoculated into four hormone-free liquid media (1/2 MS, B5, 1/2 MS vB5 and B5 vMS). After four week-culture in the dark at 25 C, the contents of 1, 2, 5, 6, 12 and 13 in these hairy roots were determined by HPLC (Table 5). 

Skills in separation of grain components and their analysis are needed to address these problems. Some examples of naturally occurring antinutritional compounds are phytates (already mentioned), phenols, tannins, and trypsin- and a-amylase inhibitors. Phenols and tannins bind with and precipitate proteins in food systems, thus decreasing digestibility. Minimizahon of these compounds in cereals is an objective. 

Dubourdieu (1992) points out that wine yeasts Saccharomyces cerevisiae also contains the cinnamate decarboxylase and thus are capable of producing the vinyl phenol intermediate. However, flavonoid phenols (tannins) inhibit its activity hence, the formation of volatile phenols in red and rose wines is significantly less than that seen in white wine fermentations. Activity of cinnamate decarboxylase in the case of Brettanomyces and Dekkera, however, is not inhibited by polymeric phenols. 

Shikimic acid phenols, tannins, aromatic alkaloids... 

Leaves Mimosine, terpenoids, flavonoids, glycosides, alkaloids, quinone, phenols, tannins, saponins, and coumarins [42-43, 46]... 

Ionic bonds Phenolics, tannins, bases, acids... 

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