Crystallization of artemisinin from chromatography fractions of Artemisia annua extract

摘要

Artemisinin is an important natural product recommended by World Health Organization (WHO) for the use in combination with other drugs against drug resistant Plasmodium falciparum induced malaria [1]. Artemisinin is obtained mainly from dried leaves of the plant Artemisia annua. Existing processes include extraction of dried leaves of A. annua by using organic solvents and subsequent purification of artemisinin from crude extract [2-4]. Recently, Levesque et al. [5] have reported continuous flow synthesis of artemisinin from artemisinic acid, a precursor of artemisinin, by using flow chemistry. In both cases artemisinin needs to be purified from the impurities and crystallization is the method of choice to obtain artemisinin in pure form. However, crystallization of artemisinin especially from crude extract is challenging and often plagued by poor yields possibly due to the complex nature of crude extract.