Catechu tannic acid

Catechu and gambier have catechu-tannic acid and catechin for their essential components. They may be adulterated with mineral matter (earth, ochre, clay, sand), starch, dextrin, extraneous tanning materials and dried blood. 

Catechu and gambter usually contain 12-25% of water, 2-5% of mineral matter, 24-48% of catechu-tannic acid and 2-12% of catechin. 

Catechu-tannic Acid.—tannic acid which is found in gum cate- j chin and which yields catechin, protocatechuic acid and p3rrocatechinoh is known as catechu-tannic acid. 

Querci-tannic Acid.— Another tannic acid, probably also a catechu-tannic acid, as it yields the same products as above, is known as querci-tannic acid. It derives this name from Quercus, the generic name for the oak tree, as it is found in oak bark, but not, however, in oak galls. 

The principal constituents of catechu are catechin and catechu-tannic acid. 

Catechu-tannic Acid.—This body, also known as catechin-red, is obtained by extracting catechu with cold water, or by heating catechin with water to 110°. It precipitates gelatine but not tartar-emetic, and gives a green coloration with ferric acetate. 

Incompat Acids, alkalies, alum, ammonia water, amyl nitrite benzoates betanaphthol, phenol, calomel, chloral hydrate, copper sulfate, ferric chloride ferrous sulfate chromium trioxide (chromic acid), cinchona alkaloids, hydrocyanic acid iodides iodine Lead subacetate mercuric chloride, orthoform potassium permanganate, resorcinol, sod. bicarbonate sod. salicylate (in powder) soln arsenic and mercury iodide, spirit nitrous ether (unless prescribed with sod, bicarbonate), syrup ferrous iodide, tartar emetic tannic acid, thymol, urethane, infusions of catechu, cinchona, rose leaves and uva ursi tinctures of catechu, ferric chloride, cinchona, hamanielis iodine, kino, and rhubarb. 

Antidotes.— Tannic acid, or agents containing it, e,g. powdered gall-nuts, catechu, c. 

Because of their high tannin content, black catechu and pale catechu have astringent, antibacterial, and other pharmacological properties, as well as toxicities of tannins (see tannic acid). 

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