Plants showing antiplasmodial activity--from crude extracts to isolated compounds.

Abstract

The derivation of important antimalarial compounds started with the discovery of Cinchona bark powder with wine. Subsequently, post World War-I was a period of intensive work in maintaining such ethnobotanical records, in which the use of quinine has remained the drug of choice in malaria. After World War-II new chemical techniques were used to fractionate and isolate, and also for structure determinations, which led to an ever increasing number of potential antiplasmodial compounds. Recently experimental studies in animals and in clinical trials, showed the emergence of CQ-sensitive and CQ-resistant strains of Plasmodium. This paper is an attempt to update a historical list of antimalarial plants and their natural products as studied by pharmacognostic extraction methods of crude drug research of those times. Further an attempt has been undertaken to list the compounds as classified into three major groups, namely alkaloids, terpenes and quassinoids and aromatic and miscellaneous compounds. The most promising is a quassinoid, artemisinin derived from Artemisia annua which has caused a resurgence for the quest of newer antimalarial compounds.