Antimalarial activity of new water-soluble dihydroartemisinin derivatives
作者:Ai Jeng Lin、Daniel L. Klayman、Wilbur K. Milhous
DOI:10.1021/jm00394a037
日期:1987.11
The usefulness of sodium artesunate (3), a water-soluble derivative of artemisinin (1), is impaired by its poor stability in aqueous solution. To overcome the ease of hydrolysis of the ester group in 3, a new series of derivatives of dihydroartemisinin (2) was prepared in which the solubilizing moiety, which contains a carboxylate group, is joined to dihydroartemisinin by an ether rather than an ester linkage. The new derivatives were prepared in good yield by treatment of dihydroartemisinin with an appropriate alcohol under boron trifluoride etherate catalysis at room temperature. All major condensation products are the beta isomer. Hydrolysis of the esters with 2.5% KOH/MeOH gave the corresponding potassium salts, which were converted to free acids (8b-d) by acidification. The derivatives were tested in vitro against two clones of human malaria, Plasmodium falciparum D-6 (Sierra Leone clone) and W-2 (Indochina clone). No cross-resistance to the antimalarial agents mefloquine, chloroquine, pyrimethamine, sulfadoxine, and quinine was observed. In general, the new compounds are more effective against the W-2 than the D-6 strain. Esters (5a-d) possess activity comparable to that of the parent compounds 1 and 2; however, conversion of the esters to their corresponding carboxylates (7a-d) or acids (8b-d), with the exception of artelinic acid (8d), drastically decreases the antimalarial activities in both cell lines. Artelinic acid, which is both soluble and stable in 2.5% K2CO3 solution, possesses superior in vivo activity against Plasmodium berghei than artemisinin or artesunic acid.
LIN, AI JENG;KLAYMAN, DANIEL L.;MILHOUS, WILBUR K., J. MED. CHEM., 30,(1987) N 11, 2147-2150
作者:LIN, AI JENG、KLAYMAN, DANIEL L.、MILHOUS, WILBUR K.
DOI:——
日期:——
Immunoquantitative analysis of artemisinin from Artemisia annua using polyclonal antibodies
作者:Jorge F.S. Ferreira、Jules Janick
DOI:10.1016/0031-9422(95)00542-0
日期:1996.1
successfully detected artemisininfrom crude extracts in concentrations as low as 1.5 ng ml-1; and was epsilon 400-fold more sensitive than the HPLC-EC. The ELISA successfully detected and quantified artemisinin in different organs of greenhouse-grown plants and in eight clones of Artemisiaannua grown in tissue culture but artemisinin was overestimated owing to cross-reactivity of the antibodies with artemisinin-related