A Review on Properties and Pharmacological Activity of Naphthoquinone and its Derivatives

Naphthoquinone forms the central chemical structure of many natural compounds, most notably the K Vitamins. 2-Methylnaphthoquinone is a more effective coagulant than vitamin K. Naphthoquinone derivatives are cytotoxic, they have significant antibacterial, antifungal, antiviral, insecticidal, anti-inflammatory, and antipyretic properties. Quinone derivatives may be toxic to cells by a number of mechanisms including redox cycling, arylation, intercalation, induction of DNA strands breaks, generation of free radicals and alkylation via quinone methide formation. 5-Hydroxy-1, 4-naphthoquinone, juglone, which is found in walnut hulls and leaves, is toxic and behaves as a weak tumor promoter in mouse skin. The bioactive quinones include lapachol, α-lapachone and β-lapachone, originally isolated from the heartwood of trees of the Bignoniaceae family (Tabebuia sp). The inner bark of Tabebuia avellanedae, commonly known as "pau d'arco" is used as an analgesic, an anti-inflammatory, an antineoplasic and a diuretic by the local people in the northeastern regions of Brazil. A series of synthetic isoxazolyl naphthoquinones was assayed in vitro and in vivo on T. cruzi, and the most active was (E)-4-(3,5-dimethylisoxazol-4-ylimino)-2-hydroxynapththalene-1(4H)-one, which led to parasitemia reduction in infected mice. Plumbagin (5-Hydroxy-2-methyl-1,4-naphthoquinone) has been found to be active on epimastigote forms. Naphthoquinones are one of the groups of secondary metabolites widespread in nature. Catalysis of dioxygen reduction to hydrogen peroxide at the surface of carbon paste electrodes is modified by 1, 4-naphthoquinone and some of its derivatives.