ABSTRACT Zonisamide (ZNS), a commonly used anticonvulsant, scavenged hydroxyl radicals at a clinically relevant concentration. Reactants of ZNS with hydrogen peroxide and with hydrogen peroxide plus UV irradiation, yielding hydroxyl radicals, were analyzed by the LC/MS technique. Many small fragments were found in the both reactions, suggesting that ZNS was decomposed not only by hydroxyl radicals but also by hydrogen peroxide. Furthermore, mass-fragment-grams showed that m/z: 213 (ZNS itself) was decreased markedly and m/z: 118 (may be a decomposed product by ring cleavage of ZNS) was detected specifically by treatment with hydroxyl radical. These data suggested that ZNS may react directly with free radicals.
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Tanaka, K. , Nanba, T. , Furubayashi, T. , Noda, Y. , James Willmore, L. and Mori, A. (2012) Molecular basis of scavenging effect of zonisamide on hydroxyl radical in vitro. Journal of Biophysical Chemistry, 3, 256-258. doi: 10.4236/jbpc.2012.33030.
 Mori, A., Noda, Y. and Packer, L. (1998) The anticonvulsant zonisamide scavenges free radicals. Epilepsy Research, 30, 153-158.
 Asanuma, M., Miyazaki, I., Diaz-Corrales, F.J., Miyoshi, K., Ogawa, N. and Murata, M. (2008) Preventing effects of a novel anti-parkinsonian agent zonisamide on dopamine quinone formation. Neuroscience Research, 60, 106-113. doi:10.1016/j.neures.2007.10.002
 Mori, A., Noda, Y., Kaneyuki, T. and Packer, L. (2000) Antiepileptic mechanism of zonisamide involves its antioxidant effect in the brain. In: Karanithi, N. and Packer, L., Eds., Microneutrients and Health: Molecular Biological Mechanisms, AOCS Press, Champaign, 236-246.
 Rosen, G.M. and Rauckman, E.J. (1984) Spin trapping of superoxide and hydroxyl radicals. In: Packer, L., Ed., Methods in Enzymology, Oxygen Radicals in Biological Systems, Academic Press, San Diego, 198-209.
 Janzen, E.G. (1984) Spin trapping. In: Packer, L., Ed., Methods in Enzymology Oxygen Radicals in Biological Systems, Academic Press, San Diego, 188-198.
 Ito, T., Yamaguchi, T., Miyazaki, H., Sekine, Y., Shimizu, M., Ishida, S., Yagi, K., Kakegawa, N., Seino, M. and Wada, T. (1982) Pharmacokinetic studies of AD-810, a new antiepileptic compound. Phase I trials. Arzneinmittelforsch, 32, 1581-1586.
 Nakasa, H., Komiya, M., Ohmori, S., Rikihisa, T., Tiuchi, M. and Kitada, M. (1993) Characterization of human liver microsomal cytochrome P450 involved in the reductive metabolism of zonisamide. Molecular Pharmacology, 44, 216-221.
 Nakasa, H., Ohmori, S. and Kitada, M. (1996) Formation of 2-sulphamoylphenol from zonisamide under aerobic conditions in rat liver microsomes. Xenobiotica, 26, 495-501. doi:10.3109/00498259609046727
 Kitamura, S., Sugihara, K., Kuwasako, M. and Tatsumi, K. (1997) The role of mammalian intestinal bacteria in the reductive metabolism of zonisamide. Journal of Pharmacy and Pharmacology, 49, 253-256.