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Dihydroartemisinin : ウィキペディア英語版 | Dihydroartemisinin
Dihydroartemisinin (also known as dihydroqinghaosu, artenimol or DHA) is a drug used to treat malaria. Dihydroartemisinin is the active metabolite of all artemisinin compounds (artemisinin, artesunate, artemether, etc.) and is also available as a drug in itself. It is a semi-synthetic derivative of artemisinin and is widely used as an intermediate in the preparation of other artemisinin-derived antimalarial drugs. It is sold commercially in combination with piperaquine and has been shown to be equivalent to artemether/lumefantrine. ==Chemistry== The lactone of artemisinin could selectively be reduced with mild hydride-reducing agents, such as sodium borohydride, potassium borohydride, and lithium borohydride to dihydroartemisinin (a lactol) in over 90% yield. It is a novel reduction, because normally lactone cannot be reduced with sodium borohydride under the same reaction conditions (0-5 ˚C in methanol). Reduction with LiAlH4 leads to some rearranged products. It was surprising to find that the lactone was reduced, but that the peroxy group survived. However, the lactone of deoxyartemisinin resisted reduction with sodium borohydride and could only be reduced with diisobutylaluminium hydride to the lactol deoxydihydroartimisinin. These results show that the peroxy group assists the reduction of lactone with sodium borohydride to a lactol, but not to the alcohol which is the over-reduction product. No clear evidence for this reduction process exists.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Dihydroartemisinin」の詳細全文を読む
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