Herbs - Plant Constituents - Acids

Weak acids, usually in the form of salts or esters, are present in most plants. They are chemically differentiated by how many carboxyl (acid) groups are present in the molecule. An example is an ester of Valeric acid from Valerian, used as a sedative in orthodox medicine. Formic acid found in Nettles causes the sting but can also be used in a stimulating liniment. Acids containing more than 12 carbon atoms form the basis of polyunsaturated and saturated fats which play an important role in nutrition. Aromatic acids, such as benzoic acid, are composed of a benzene ring and a carboxyl group. They are medically important as inhalants for upper respiratory congestion and infections and are useful externally for infections and irritations.