Preparation of Naphthoquinone Derivatives from Plumbagin and Their Ichthyotoxicity.

Abstract

Various naphthoquinone derivatives were prepared from a natural product, 5-hydroxy-2-methyl-1, 4-naphthoquinone (plumbagin); these were mostly substituted at C-3 through carbon-carbon bond formation mediated by a metal-based oxidant such as lead tetraacetate in the presence of various carboxylic acids. The halogenated compounds showed stronger ichthyotoxicity than plumbagin, but other derivatives were less active.