关键词: 色胺酮, 吲哚醌, 邻氨基苯甲酸, 仿生合成

Abstract:

Tryptanthrin possesses remarkable antitumor, anti-inflammatory and antibacterial activity as one of the active ingredients in medicinal plants Strobilanthes cusia, Polygonum tinctorum Lour and Isatis Einetorial. However, despite a variety of synthesis methods had been developed, the yield was low, and the cost was high due to the use of isatoic anhydride. Furthermore, not a single current synthesis method is efficacious and simple enough to meet the requirement for the use in lab and industry. Our previous study on the distribution of tryptanthrin in Isatis Einetorial demonstrated that tryptanthrin was a product resulted from the reaction between isatin and anthranilic acid in the leaves during a drying process instead of a constitutive component within the plant. In order to develop an efficient and simple method, a biomimetic synthesis of tryptanthrin was carried out using isatin and anthranilic acid existing naturally in the medical plants as reaction agents, with THF and toluene as solvents in the presence of catalyst POCl₃. A high yield of 40.3% was obtained, and the product showed a structure characterization same to that of standard sample. After the first trial, total other 14 derivatives of tryptanthrin were synthesized using the same method with relatively reasonable yields. Moreover, the raw materials used in this study were readily available and much cheaper than those in conventional methods, and the reaction conditions were relatively mild. It implied that the synthesis method reported could be applied widely.

Key words: Tryptanthrin, Isatin, Anthranilic acid, Biomimetic synthesis