Synthesis Of Juglone And Its Derivatives

Juglone (5-hydroxy-1,4-naphthoquinone) is a natural 1,4-naphthoquinone found in root bark, branch bark and leaves of Juglans mandshurica, a traditional herbal medicine used for a long time as a folk remedy. Juglone has exhibited cytotoxic action against various tumor cells and also has antifungal, antiviral and antibacterial activities.To begin with, the thesis reviews the isolation, chemical structures, biological activities and synthetic methods of natural naphthoquinones, such as juglone, plumbagin, lapachones and shikonins.Secondly, as a result of juglone's cytotoxic effects against normal cells, clinical application is greatly restricted. Juglone's high toxicity drives us to search for its derivatives with lower toxic side effects. The study indicated that naphthoquinone is a indispensable structure for antitumor activities. Therefore, we design eight juglone derivatives by introducing side chains of different sizes on the different positions of its stucture.The synthesis of the eight compounds was accomplished by a few routes through a strategy featuring acylation reaction on the different positions of the naphthalene ring as the key step. Using a serious of reactions such as desugarization, etherification, acylation reaction, Clemmensen reduction and oxidation reaction, the eight derivatives was synthesized from 4,8-dihydroxynaphthol-β-D-glucoside. All products were determined by their physicochemical properties, ¹H NMR and ¹³C NMR spectra.