3,4-dihydroxybenzoic acid, also known as protocatechuic acid, is a phenolic acid found naturally in a variety of fruits and vegetables. It has good solubility in water and is also soluble in ethanol and ether. The molecular formula of 3,4-dihydroxybenzoic acid is C7H6O4, molecular weight 154.12, CAS number 99-50-3, melting point about 200°C, density 1.54g/cm3.
Currently available on the market, 3,4-dihydroxybenzoic acid usually appears as a white to brown crystalline powder that changes color when exposed to air and turns blue-green when exposed to ferric chloride aqueous solution. Storage of 3,4-dihydroxybenzoic acid is recommended in a cool, dark environment.
3,4-dihydroxybenzoic acid has many functions such as antibacterial, nerve protection, detoxification snake venom and so on. In recent years, it has been vigorously applied in medicine, health care products, feed and other industries. The production and market demand of 3,4-dihydroxybenzoic acid are increasing. Visible its market development uses the big space.