1,4-Naphthoquinone forms yellow triclinic crystals and has an odor similar to benzoquinone. It is sparingly soluble in cold water, slightly soluble in petroleum ether, and freely soluble in most polar organic solvents. In alkaline solutions it produces a reddish-brown color. Because of their aromatic stability, 1,4-naphthoquinone derivatives are known to possess anti-bacterial and anti-tumor properties.  Naphthoquinone forms the central chemical structure of many natural compounds, most notably the K vitamins.  Medicinal uses  Naphthoquinone derivatives have significant pharmacological properties. They are cytotoxic, they have significant antibacterial, antifungal, antiviral, insecticidal, anti-inflammatory, and antipyretic properties. Plants with naphthoquinone content are widely used in China and the countries of South America, where they are used to treat malignant and parasitic diseases.