title: Novel 2-substituted nitronyl nitroxides as free radical scavengers: synthesis, biological evaluation and structure-activity relationship.
abstract: To develop more potent small molecules with enhanced free radical scavenger properties, we designed and synthesized a series of nitronyl nitroxide derivatives 4a-h. A lead compound 4f was discovered based on Ach-induced vascorelaxation assay. Further chemical modification based on this scaffold provided a new series of 2-substituted phenylnitronyl nitroxide derivatives 6a-s. The newly synthesized compounds 6a-s possess improved radical scavenger's activity based on PC12 cell survival assay. Compounds 6g,n,o, and s are some of the most potent compounds in terms of NO, H(2)O(2), and OH scavenging ability. 2-Substitued phenylnitronyl nitroxides had a higher radical scavenging activity with the electron-donating group (EDG). In contrast, the introduction of electron-withdrawing group (EWG) to the aromatic ring led to a dramatic decrease in its radical scavenging activity. These results suggest that the electron-donating group (EDG) of the aromatic ring may be an important factor influencing the radical scavenging behavior of these compounds, and the potency of free radical scavenging activity largely depended on the position and electronic properties of the phenyl ring substituents. The enhanced radical scavenging capacities of the novel 2-substituted nitronyl nitroxides may be potential drug leads against the deleterious action of ROS (reactive oxygen species)/RNS (reactive nitrogen species).
authors.affiliation: College of Pharmaceutical Sciences, Capital University of Medical Sciences, Beijing, PR China.
authors.forename: Yihui
authors.initials: Y
authors.lastname: Wu
authors.forename: Lanrong
authors.initials: L
authors.lastname: Bi
authors.forename: Wei
authors.initials: W
authors.lastname: Bi
authors.forename: Zeng
authors.initials: Z
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Jingfang
authors.initials: J
authors.lastname: Ju
authors.forename: Shiqi
authors.initials: S
authors.lastname: Peng
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D003497:Cyclic N-Oxides / Q000138:chemical synthesis / Q000494:pharmacology*; D004583:Electrons; D016166:Free Radical Scavengers / Q000138:chemical synthesis / Q000494:pharmacology*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000378:metabolism; D007093:Imidazoles / Q000138:chemical synthesis / Q000494:pharmacology*; D009589:Nitrogen Oxides / Q000138:chemical synthesis / Q000494:pharmacology*; D010084:Oxidation-Reduction; D016716:PC12 Cells; D051381:Rats; D026361:Reactive Nitrogen Species / Q000737:chemistry / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D006841:Hydrocarbons, Aromatic; D007093:Imidazoles; D009589:Nitrogen Oxides; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide