Endoperoxide bridge activation

"Endoperoxide bridge activation" refers to the chemical cleavage and reduction of the peroxide bond in endoperoxide-containing drugs, primarily antimalarials such as artemisinins and related synthetic molecules[2][5][8][6][1][4]. When these drugs encounter *intra-parasitic Fe(II)* (iron, largely from heme released during hemoglobin digestion), the iron catalyzes the **homolytic cleavage of the endoperoxide bridge**, generating reactive oxygen species—primarily *carbon-centered radicals* and *oxyl radicals*[2][5][8][6][1]. These cytotoxic species then cause parasite death by: - **Alkylating heme and parasite proteins** - **Causing membrane damage** - **Inducing oxidative stress** - **Inhibiting protein and nucleic acid synthesis** - **Depolarizing mitochondrial or other membranes in specific organisms**[2][5][1][4][6] This process is essential for the activity of drugs like artemisinins; drugs lacking the endoperoxide bridge (e.g. deoxyartemisinin) have no antimalarial effect[2][5]. While "endoperoxide bridge activation" is vital pharmacodynamically, it is **not a therapeutic target itself**, nor is it a gene, protein, receptor, or enzyme that could be directly modulated biochemically or genetically. It is therefore **incorrect to list "endoperoxide bridge activation" as a target molecule/receptor**. For further molecular and pharmacological insights, see artemisinins or trioxane antimalarial mechanisms[2][5][8][1][4][6].

The chemical cleavage and reduction of the peroxide bond in endoperoxide-containing drugs, primarily antimalarials such as artemisinins and related synthetic molecules. This process is catalyzed by intra-parasitic Fe(II) (iron, largely from heme released during hemoglobin digestion), leading to homolytic cleavage of the endoperoxide bridge. This generates reactive oxygen species, primarily carbon-centered radicals and oxyl radicals. These cytotoxic species cause parasite death by alkylating heme and parasite proteins, causing membrane damage, inducing oxidative stress, inhibiting protein and nucleic acid synthesis, and depolarizing mitochondrial or other membranes in specific organisms. This activation process is essential for the antimalarial activity of these drugs.