Sesquiterpenes isolated from Artemisia annua

Foglio MA, Dias PC, Antonio MA, Possenti A, Rodrigues RA, da Silva EF, Rehder VL, de Carvalho JE. (2002) Antiulcerogenic activity of some sesquiterpene lactones isolated from Artemisia annua. Planta Med 68 515-518. 

Stiles, L. H., Leather, G. R., and Chen, P. K. 1994. Effects of two sesquiterpene lactones isolated from Artemisia annua on physiology of Lemna minor. J. Chem. Ecol. 20, 969-978... 

Artemisinin 1, a naturally occurring sesquiterpene peroxy-lactone, has been isolated in up to 0.25% yield from the dry leaves of Artemisia annua L.1 Interest in artemisinin is based on its phytomedicinal properties. In 168 b.c. China, as described in a Treatment of 52 Sicknesses, the leaves of A. annua (Qinghao) were used for the treatment of chills and fever.2 It was not until 1972 that the active antimalarial agent qinghaosu was isolated in pure form. This allowed for the unequivocal elucidation of its structure through the use of x-ray crystallography. This complex tetracyclic peroxide is now referred to as artemisinin in various sources such as Chemical Abstracts or the Merck Index. 

Artemisinin (23), isolated from a Chinese medicinal plant, annual wormwood Artemisia annua L.), is a unique sesquiterpene lactone bearing an endoperoxide moiety. This compound displays a strong antimalarial activity and inhibits seed germination and plant growth.11... 

Qinghao (Artemisia annua L.) is an important medicinal herb, which has h>een used in the Chinese traditional system of medicine for many centuries. In 1972, Chinese scientists isolated (+)-artemisinin (7, qinghaosu) from the above plant, which is indigenous to China [27-30]. Artemisinin is a sesquiterpene lactone peroxide, whose structure and synthesis have been worked out [27,28]. It has marked activity against both chloroquine-sensitive and resistant strains of Plasmodium falciparum and is particularly suitable for treating cerebral malaria as it is very fast acting [29-31]. 

Artemisinin (Fig. 1), isolated in 1972 from Chinese medicinal plant Artemisia annua L, is a novel antimalarial drug with a sesquiterpene lactone structure containing an internal endoperoxide linkage which is essential for the drug s activity. Artemisinin and its derivatitives form a series of antimalarial compounds with activity against chloroquine-resistant malaria parasites. In contrast to chloroquine, artemisinin penetrates the blood brain barrier, which makes it especially valuable for the treatment of cerebral malaria. ... 

An effective antimalarial constituent, artemesinin (128), was isolated from a Chinese medicinal herb, Artemisia annua (Asteraceae). A promising antimalarial, but only weakly toxic sesquiterpene lactone, was isolated from this plant (Fischer, 1991b Klayman, 1985, 1989 Lewis, 1992 Pieman, 1986a). A similar compound, yingzhaosu A (129), from Artabotrys uncinatus (Annonaceae) also has efficacy as an antimalarial agent (Borris and Schaeffer, 1992). 

Artemisinin, a sesquiterpene lactone endoperoxide and isolated from aerial parts of Artemisia annua L. plants (family Asteraceae commonly known as sweet wormwood), is popular as a potent, promising, highly effective, safe, and best therapeutic agent against drug-resistant strains of Plasmodium sp. The low yield of artemisinin content, is a serious limitation to its ability and affordablity to the most malaria sufferers. The chemically synthesized artemisinin is also costly due to low yield of the process. The World Health Organization (WHO) recommends the use of artemisinin-based combination therapies (ACTs), for the first-line treatment of malaria. To date, A. annua L. 

Plant sesquiterpenes comprise a large class of natural products with a number of biological activities, including some with interesting herbicidal and allelopathic potentials [19]. Artemisinin (Fig. 1) and its structural analog arteether (Fig. 1) are sesquiterpene endoper-oxide lactones with strong phytotoxic activity isolated from the shoots of Artemisia annua [20, 21]. 

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