Artemisinin extraction

Analytic Methods for Artemisinin Extraction and Quantification from Artemisia annua... 

Lapkin AA, Peters M, Greiner L, Chemat S, Leonhard K, Liauw MA, Leitner W. (2010) Screening of new solvents for artemisinin extraction process using ab initio methodology. Green Chem 12 241-251. 

Quispe-Condori S, Sanchez D, Foglio MA, Rosa PTV, Zetzl C, Brunner G Meireles MAA. (2005) Global yield isotherms and kinetic of artemisinin extraction from Artemisia annua L leaves using supercritical carbon dioxide. J Supercriti Fluids 36 40 8. 

How do traditional remedies fare in such trials Some perform quite well and prove to be highly effective, but others are no better than placebos. One striking success is an extract of sweet wormwood (Artemisia annua), which Chinese physicians have prescribed for the chills and fevers of malaria for more than two thousand years. About twenty-five years ago, Chinese chemists obtained from sweet wormwood its principal active component, a compound now called artemisinin. Clinical trials on malaria patients in Southeast Asia agreed with Chinese tradition on the value of artemisinin and also identified a few even more useful drugs prepared from it in the laboratory. These compounds are effective against the deadliest form of malaria and are now frequently the therapies of choice for treating it. 

Haynes RK, Vonwiller SC. (1994) Extraction of artemisinin and artemisinic acid Preparation of artemether and new analognes. Trans R Soc Trap Med Hyg 88 23-26. 

Artemisinin, a tetracyclic 1,2,4-trioxane isolated from Artemisia annua L., is currently recommended as a first-line agent against Plasmodium falciparum malaria. Artemisinin and its synthetic derivatives have also been shown to be promising prototypes for the development of new antiproliferative agents. This chapter presents the recent advances on the analytic methods for extraction and quantification of artemisinin from A. annua plants as well as the biological properties of this natural product. 

FDA) for use in humans to treat malaria because this drug is considered a safe drug with few side effects.These features prompted various scientists around the world to evaluate the potential of artemisinin (1) and derivatives to control cancer cells proliferation. This chapter reviews the recent advances on analytical methods for extraction and quantification of artemisinin (1) from A. annua. Examples of artemisinin-derivatives with antiproliferative activities are listed, describing the structure-activity relationships of 96 compounds. This knowledge is essential for future development and use of artemisinin derivatives in cancer therapy. The mechanism of action of artemisinin and derivatives on cancer cells have been well reviewed in literature and therefore is not discussed in this chapter. 

According to Coimbra et solvents play a central role in the majority of chemical and pharmaceutical industrial processes. The most used method to obtain artemisinin (1) from A. annua is through the use of organic solvents such as toluene, hexane, cyclohexane, ethanol, chloroform and petroleum ether. Rodrigues et al described a low-cost and industrial scaled procedure that enables artemisinin (1) enhanced yields by using inexpensive and easy steps. Serial extraction techniques allowed a reduction of 65% in solvent consumption. Moreover, the use of ethanol for compound extraction is safer when compared to other solvents. Flash column pre-purification employing silicon dioxide (Zeosil ) as stationary phase provided an enriched artemisinin (1) fraction that precipitated in hexane/ethyl acetate (85/15, v/v) solution. These results indicate the feasibility of producing artemisinin (1) at final cost lowered by almost threefold when compared to classical procedures. 

Tzeng et al studied the SCCO2 extractions with addition of 16.25% ethyl alcohol as a co-solvent to obtain scopoletin and artemisinin (1) from A. annua. A two-factor central composite experimental design was adopted to determine the optimal extraction conditions. Two-hour ethanol-modified SCCO2 extractions was more efficient than 16 h-Soxldet hexane extraction to provide pure artemisinin (1). ... 

Rodrigues RAF, Foglio MA, Junior SB, Santos AS, Rehder VLG. (2006) Optimization of the extraction and isolation of the antimalarial drug artemisinin from Artemisia annua L. Quim Nova 29 368-372. 

Tzeng TC, Lin YL, Jong TT, Chang CMJ. (2007) Ethanol modified supercritical fluids extraction of scopoletin and artemisinin from Artemisia annua L. Separ PurifTech 56 18-24. 

Hao JY, Han W, Huang SD, Xue BY, Deng X. (2002) Microwave-assisted extraction of artemisinin from Artemisia annua L. Sep Purif Technol 28 191-196. 

In 1972, Chinese researchers isolated, by extraction at low temperature from a plant, a crystalline compound that they named qinghaosu [the name artemisinin (la) is preferred by Chemical Abstracts, RN 63968-64-9]. The plant source of artemisinin is a herb, Artemisia annua (Sweet wormwood), and the fact that artemisinin is a stable, easily crystallizable compound renders the extraction and purification processes reasonably straightforward. The key pharmacophore of this natural product is the 1,2,4-trioxane unit (2) and, in particular, the endoperoxide bridge. Reduction of the peroxide bridge to an ether provides an analogue, deoxyartemisinin 3, that is devoid of antimalarial activity. ... 

A new gas chromatography (GC) method was developed to characterize artemether 28a and its metabolites in body fluids. The extracts were derivatized and then separated on an optimized capillary GC system and identified by chemical ionization MS using ammonia as the reagent gas <1998JCH(B)101>. A sensitive, selective, and reproducible GC-MS-SIM method has also been developed for the determination of artemether 28a and dihydroartemisinin 29a in plasma, using artemisinin 9a as an internal standard <1999JCH(B)251>. 

An FIPLC method using electrochemical detection in the reductive mode for the determination of artemether 28a and its metabolite dihydroartemisinin 29a <1997JCFI(B)145> and for the simultaneous quantification of artesunate 31 and dihydroartemisinin 29a in plasma has been developed <1997JCFI(B)259, 1998JCFI(B)201>. An effective reversed-phase FIPLC method using electrochemical and UV detection has been developed for the simultaneous determination in plant extracts of artemisinin and its bioprecursors such as arteannuin B 32a, and artemisitene 27 <1995JNP798, 2001JIC489>. 

Artemisinin 9a has been extracted from Artemisia annua L. by supercritical fluid extraction and analyzed by supercritical fluid chromatography (SFC) using a capillary column coupled with a flame ionization detector <1997JCFI(A)353>. The SFC method has also been used for the determination of artemisinin in whole blood <1995JCH(B)183>. 

Malaria is one of the most prevalent diseases in the world. Although there are numerous drugs on the market for both the treatment and prevention of the disease, multiple drug resistance by parasites is now ubiquitous in all parts of the world where malaria is endemic.55 Therefore, there is an increasing need for the development of new antimalarial drugs, especially ones that possess novel modes of action. The antimalarial properties of nonalkaloidal compounds such as artemisinin (54) and yingzhaosu A (55) have attracted considerable attention because of the limited availability of the natural product by extraction from the Chinese Artemisia annua plant.56 58... 

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