A concise synthesis of the DNA-intercalating and antimalarial alkaloid cryptolepine and its fluorescence behaviour in solvents of different polarities

Abstract

A microwave-induced rapid and facile synthesis of the DNA-intercalating and antimalarial drug cryptolepine is described. The key step in this synthesis involves the aqueous-phase base-catalyzed condensation of isatin and 1-acetyl-1H-indol-3-yl acetate which has been simplified and expedited by dielectric heating, employing an ordinary domestic microwave oven. The method transforms the synthesis of an important drug molecule from a prohibitively lengthy process to a matter of a few minutes with a much improved yield. Dual absorption and fluorescence is observed from the molecular system in solvents of different polarity thus providing valuable insight into its binding modes toward protein or DNA.