Gallotannin

Gallotannins are hydrolyzable tannins (as opposed to the non-hydrolysable catechin ), chemically they put sugar esters of gallic acid dar.

Properties

In tannins is the acid radical of two or three linked depsidisch gallic acids, digallic acid or so Trigallussäure. In the ellagitannins is the sugar with ellagic acid, or the precursor Hexahydroxydiphensäure esterified.

Gallotannins have some microbicidal and anti-tumor effects.

Biosynthesis

The biosynthesis of gallotannins is based on UDP -glucose.

Color reactions

Color reactions with gallotannins:

• → blue color
• → green, green precipitates at high concentrations
• Proteins → rainfall
• Ellagitannins with nitrous acid () → first crimson, indigo blue later