Chapter 4 - Biological and Pharmacological Activities of Carbazole Alkaloids

Abstract

The chapter presents a summary on some of the important biological and pharmacological activities of carbazole alkaloids. A wide range of synthetic analogs based on natural products emerged as therapeutically useful anti-tumor agents. Among these natural products, the carbazole alkaloids constitute one of the important classes of natural products. Within the carbazole alkaloids, natural and synthetic congeners of the pyrido’4,3- b ]carbazole and the indolo’2,3- a ]pyrrolo’3,4- c ]carbazole alkaloids comprise a large group of therapeuti­cally useful anti-tumor agents, either in current clinical use, or in the various stages of clinical development. Among the various carbazole derivatives, murrayanine (3-formyl-1-methoxycarba­zole) was the first carbazole alkaloid isolated from a natural source and it shows antimicrobial properties. The tubingensins A and B showed activity against the widespread crop pest Heliothis zea , and display in vitro anti-viral activity against herpes simplex virus type 1. The anti-inflammatory properties of several carbazole derivatives have attracted widespread attention. Some acidic tetrahydrocarbazoles have been shown to have anti-inflammatory activity. N-Alkylamino carbazoles possess significant anti-convulsant and diuretic activity. Murrayaquinone A was found to produce a triphasic inotropic response of guinea-pig papillary muscle. This triphasic inotropic response is mediated through a mechanism involving ATP production.