| Description | TEMPOL is a piperidine nitroxide and spin label with superoxide dismutase (SOD) mimetic activity. It inhibits lipid peroxidation in rat liver microsomes with 50% inhibition of microsomal lipid peroxidation (IP50) values of 117, 61, and 381 μM for peroxidation induced by iron plus NADPH, iron plus ascorbate, and t-butylhydroperoxide, respectively. TEMPOL (1 mM) inhibits production of superoxide anions by 92% via a xanthine-xanthine oxidase reaction in vitro. It reduces mean arterial pressure and heart rate in spontaneously hypertensive rats (ED50s = 70 and 63 μmol/kg, respectively) when administered intravenously. TEMPOL is a cell-permeable spin label that has been used to quantify intracellular oxygen in various cell types by electron spin resonance (ESR) spectroscopy. |
| Chemical Properties | solid |
| Uses | A free radical scavenger |
| Uses | Spin label for EPR studies; phase transfer dehydration catalyst; antioxidant; inhibitor of olefin free radical polymerization. |
| Uses | Tempol, a water-soluble piperidine nitroxide derivative having nonspecific radical-scavenging and superoxide dismutase (SOD) activity, protects cultured aerobic, but not hypoxic, cells against radiation-induced killing. Protection does not depend on intracellular thiols and does not involve O2-depletion. Tempol reacts with peroxyl radicals and can also oxidize DNA-bound metal ions, thereby interfering with OH? generation. |
| Synthesis Reference(s) | Synthetic Communications, 19, p. 3509, 1989 DOI: 10.1080/00397918908052760 |
| General Description | 4-Hydroxy-TEMPO is a 4-substituted 2,2,6,6-tetramethylpiperidyl-1-oxy (TEMPO) derivative. It is a low-molecular weight compound and has been proposed as superoxide dismutase mimic. |
| Flammability and Explosibility | Nonflammable |
| Biological Activity | Superoxide scavenger that displays neuroprotective, anti-inflammatory and analgesic effects. |
| References | 1) Lipman et al. (2006), Neuroprotective effects if the stable nitroxide compound Tempol in 1-methyl-4-phenylpyridinium ion-induced neurotoxicity in the Nerve Growth Factor-differentiated model of pheochromocytoma PC12? cells; Eur. J. Pharmacol., 549 50
2) Guron et al. (2006), Acute effects of the superoxide dismutase mimetic tempol on split kidney function in two-kidney one-clip hypertensive rats; J. Hypertens., 24 387
3) Samuni and Barenholz (1997), Gamma-irradiation damage to liposomes differing in composition and their protection by nitroxides; Free Radic. Biol. Med., 23 972
4) Bernardy et al. (2017), Tempol, a Superoxide Dismutase Mimetic Agent, Inhibits Superoxide Anion-Induced Inflammatory Pain in Mice; Biomed. Res. Int., 2017 9584819
5) De Blasio et al. (2017), The superoxide dismutase mimetic tempol blunts diabetes-induced upregulation of NADPH oxidase and endoplasmic reticulum stress in a rat model of diabetic nephropathy; Eur. J. Pharmacol., 807 12 |