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Chemistry of artemisinin: an EPR study and nucleobases interaction

Abstract

In the present, the radical transformations of artemisinin, a potent antimalarial drug have been examined using EPR and EPR spin trapping techniques. The effect of light on artemisinin has been investigated at 77 K as well as with the use of phenyl butyl nitrone (PBN) spin trapping agent. While no EPR signal was observed at 77 K, intense light irradiation of artemisinin/PBN gave EPR signal characteristic of radical transformation of the PBN. The reactions of artemisinin with iron (II), manganese (II), hemin and ferrocyanide ion have been investigated by spin trapping techniques. Artemisinin/iron (II) formed spin adducts with nitrosobenzene, nitroso-t-butane and PBN. The hypertine splittings of the spin adducts were a{sub N}=1.08 mT/a{sub N}=1.25 mT/a{sub N}=0.09 mT and a{sub N}=1.56 mT/a{sub N}=0.29 mT respectively. PBN trapping of artemether/iron (II) gave similar result to artemisinin/iron (II). These results are indicative of secondary carbon-centered radical formation. While artemisinin/hemin/PBN gave very weak EPR signal, ferrocyanide under the same condition gave no signal. Incubation of artemisinin with RNA at different reaction conditions, including irradiation with light, heat and mild acidic media, revealed no RNA damage when examined by agarose electrophoresis. However, artemisinin/iron (II) caused RNA damage in pH-dependant manner. In contrast, hemin did not  More>>
Authors:
Mustafa, Damra Elhaj [1] 
  1. Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)
Publication Date:
Oct 01, 2000
Product Type:
Thesis/Dissertation
Report Number:
INIS-SD-170
Reference Number:
EDB-01:084182
Resource Relation:
Other Information: TH: Thesis (M.Sc.); 64 refs. , 4 tab. , 26 figs; PBD: Oct 2000
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANTIMICROBIAL AGENTS; BUTYL RADICALS; ELECTRON SPIN RESONANCE; ELECTROPHORESIS; MALARIA; NUCLEAR MAGNETIC RESONANCE; PH VALUE; PHENYL RADICALS; RNA; SPECTROSCOPY
OSTI ID:
20189853
Research Organizations:
University of Khartoum, Khartoum (Sudan)
Country of Origin:
Sudan
Language:
English
Other Identifying Numbers:
TRN: SD0100028042655
Availability:
Available from INIS in electronic form; Also available from the Graduate College, University of Khartoum, Khartoum (SD)
Submitting Site:
INIS
Size:
102 pages
Announcement Date:

Citation Formats

Mustafa, Damra Elhaj. Chemistry of artemisinin: an EPR study and nucleobases interaction. Sudan: N. p., 2000. Web.
Mustafa, Damra Elhaj. Chemistry of artemisinin: an EPR study and nucleobases interaction. Sudan.
Mustafa, Damra Elhaj. 2000. "Chemistry of artemisinin: an EPR study and nucleobases interaction." Sudan.
@misc{etde_20189853,
title = {Chemistry of artemisinin: an EPR study and nucleobases interaction}
author = {Mustafa, Damra Elhaj}
abstractNote = {In the present, the radical transformations of artemisinin, a potent antimalarial drug have been examined using EPR and EPR spin trapping techniques. The effect of light on artemisinin has been investigated at 77 K as well as with the use of phenyl butyl nitrone (PBN) spin trapping agent. While no EPR signal was observed at 77 K, intense light irradiation of artemisinin/PBN gave EPR signal characteristic of radical transformation of the PBN. The reactions of artemisinin with iron (II), manganese (II), hemin and ferrocyanide ion have been investigated by spin trapping techniques. Artemisinin/iron (II) formed spin adducts with nitrosobenzene, nitroso-t-butane and PBN. The hypertine splittings of the spin adducts were a{sub N}=1.08 mT/a{sub N}=1.25 mT/a{sub N}=0.09 mT and a{sub N}=1.56 mT/a{sub N}=0.29 mT respectively. PBN trapping of artemether/iron (II) gave similar result to artemisinin/iron (II). These results are indicative of secondary carbon-centered radical formation. While artemisinin/hemin/PBN gave very weak EPR signal, ferrocyanide under the same condition gave no signal. Incubation of artemisinin with RNA at different reaction conditions, including irradiation with light, heat and mild acidic media, revealed no RNA damage when examined by agarose electrophoresis. However, artemisinin/iron (II) caused RNA damage in pH-dependant manner. In contrast, hemin did not show the same effect when it was used instead of iron (II). (Author)}
place = {Sudan}
year = {2000}
month = {Oct}
}