Catechu is a natural extract derived from the wood of the Acacia catechu tree, commonly found in tropical regions. It is obtained by boiling the wood in water and then evaporating the liquid to produce a concentrated powder. This powder has a dark brown color and astringent properties. Traditionally, catechu has been used in various cultures for its medicinal benefits, including treating diarrhea and sore throats. It is also an ingredient in some types of chewing tobacco and is used in the production of certain dyes and inks due to its coloring properties.