{"id":{"repo_id":"lsu-thes","oai_identifier":"oai:repository.lsu.edu:gradschool_dissertations-1365"},"canonical_url":"https://search.dev.ndltd.org/etd/lsu-thes/oai:repository.lsu.edu:gradschool_dissertations-1365","repository":{"repo_id":"lsu-thes","name":"Lousiana State University","base_url":"https://repository.lsu.edu/do/oai/"},"display":{"title":"Peroxynitrite-mediated oxidations: nitration and nitrosation","abstract":"Using a direct ultraviolet second-derivative spectroscopy method, three peroxynitrite preparative methods were investigated for the nitrite and nitrate present either as impurities or produced during peroxynitrite decomposition: (I) ozonation of azide, reaction of hydrogen peroxide with (II) isoamyl nitrite and (III) nitrous acid. The oxidation of morpholine by peroxynitrite in the presence and absence of added carbonate gives N-nitromorpholine and N-nitrosomorpholine. Nitration and nitrosation of morpholine are catalyzed by low levels of CO<sub>2</sub>; however, excess CO<sub>2</sub> dramatically reduces the yields of nitrosation but not nitration, and the combined yields of the products are about the same under conditions of high and low concentrations of CO<sub>2</sub>. These data indicate that both nitration and nitrosation by peroxynitrite are free radical processes. The morpholine radical, formed from the reactions of carbonate and/or hydroxyl radicals with morpholine, reacts with either <sup>•</sup>NO or <sup>•</sup>NO<sub>2</sub> and serves as a common precursor for both products. The peroxynitrite-mediated oxidation of &#945;-tocopherol and &#947;-tocopherol dispersed in 1,2-dilauroyl-<i>sn</i>-glycero-3-phosphocholine liposomes in the presence and absence of added carbonate gives &#945;-tocopherylquinone and 5-nitro-&#947;-tocopherol, respectively. The formation of the products is consistent with the current understanding of the free radical nature of oxidations of peroxynitrite and its CO<sub>2</sub>-adducts; the overall reaction involves a one-electron oxidation of &#945;-tocopherol and &#947;-tocopherol by HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, followed by the reaction with <sup>•</sup>NO<sub>2</sub>. When &#945;-tocopherol and &#947;-tocopherol were present in the same liposome and exposed to peroxynitrite, there was preferential oxidation of &#945;-tocopherol over &#947;-tocopherol. An explanation for the protection of &#947;-tocopherol by &#945;-tocopherol could be that &#947;- and &#945;-tocopheryl radicals, formed from the respective reactions of &#945;-tocopherol and &#947;-tocopherol with HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, disproportionate to give &#945;-tocopherylquinone and regenerated &#947;-tocopherol. This is consistent with the lack of protection of &#947;-tocopherol by &#945;-tocopherol when &#945;-tocopherol and &#947;-tocopherol dispersed in different liposomes but present in the same incubation mixer are subjected to oxidation by peroxynitrite.","abstract_html":"Using a direct ultraviolet second-derivative spectroscopy method, three peroxynitrite preparative methods were investigated for the nitrite and nitrate present either as impurities or produced during peroxynitrite decomposition: (I) ozonation of azide, reaction of hydrogen peroxide with (II) isoamyl nitrite and (III) nitrous acid. The oxidation of morpholine by peroxynitrite in the presence and absence of added carbonate gives N-nitromorpholine and N-nitrosomorpholine. Nitration and nitrosation of morpholine are catalyzed by low levels of CO&lt;sub&gt;2&lt;/sub&gt;; however, excess CO&lt;sub&gt;2&lt;/sub&gt; dramatically reduces the yields of nitrosation but not nitration, and the combined yields of the products are about the same under conditions of high and low concentrations of CO&lt;sub&gt;2&lt;/sub&gt;. These data indicate that both nitration and nitrosation by peroxynitrite are free radical processes. The morpholine radical, formed from the reactions of carbonate and/or hydroxyl radicals with morpholine, reacts with either &lt;sup&gt;•&lt;/sup&gt;NO or &lt;sup&gt;•&lt;/sup&gt;NO&lt;sub&gt;2&lt;/sub&gt; and serves as a common precursor for both products. The peroxynitrite-mediated oxidation of &amp;#945;-tocopherol and &amp;#947;-tocopherol dispersed in 1,2-dilauroyl-&lt;i&gt;sn&lt;/i&gt;-glycero-3-phosphocholine liposomes in the presence and absence of added carbonate gives &amp;#945;-tocopherylquinone and 5-nitro-&amp;#947;-tocopherol, respectively. The formation of the products is consistent with the current understanding of the free radical nature of oxidations of peroxynitrite and its CO&lt;sub&gt;2&lt;/sub&gt;-adducts; the overall reaction involves a one-electron oxidation of &amp;#945;-tocopherol and &amp;#947;-tocopherol by HO&lt;sup&gt;•&lt;/sup&gt; or CO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;•-&lt;/sup&gt;, followed by the reaction with &lt;sup&gt;•&lt;/sup&gt;NO&lt;sub&gt;2&lt;/sub&gt;. When &amp;#945;-tocopherol and &amp;#947;-tocopherol were present in the same liposome and exposed to peroxynitrite, there was preferential oxidation of &amp;#945;-tocopherol over &amp;#947;-tocopherol. An explanation for the protection of &amp;#947;-tocopherol by &amp;#945;-tocopherol could be that &amp;#947;- and &amp;#945;-tocopheryl radicals, formed from the respective reactions of &amp;#945;-tocopherol and &amp;#947;-tocopherol with HO&lt;sup&gt;•&lt;/sup&gt; or CO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;•-&lt;/sup&gt;, disproportionate to give &amp;#945;-tocopherylquinone and regenerated &amp;#947;-tocopherol. This is consistent with the lack of protection of &amp;#947;-tocopherol by &amp;#945;-tocopherol when &amp;#945;-tocopherol and &amp;#947;-tocopherol dispersed in different liposomes but present in the same incubation mixer are subjected to oxidation by peroxynitrite.","abstract_has_math":false,"creators":["Bolzan, Rachel"],"institution":"Chemistry","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-01-01T08:00:00Z","date_published":"2002-01-01T08:00:00Z","updated_at":"2026-07-24T02:57:30Z","subjects":["mechanism"],"languages":[],"rights":["unrestricted","Release the entire work immediately for access worldwide."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-0612102-234815","https://repository.lsu.edu/gradschool_dissertations/366"],"render_values":[{"text":"etd-0612102-234815","href":null,"code":true},{"text":"https://repository.lsu.edu/gradschool_dissertations/366","href":"https://repository.lsu.edu/gradschool_dissertations/366","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.31390/gradschool_dissertations.366","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Bolzan, Rachel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2002-05-22"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-05-12T23:08:35Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Chemistry"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["mechanism"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["unrestricted","Release the entire work immediately for access worldwide."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-0612102-234815","10.31390/gradschool_dissertations.366","https://repository.lsu.edu/gradschool_dissertations/366"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Using a direct ultraviolet second-derivative spectroscopy method, three peroxynitrite preparative methods were investigated for the nitrite and nitrate present either as impurities or produced during peroxynitrite decomposition: (I) ozonation of azide, reaction of hydrogen peroxide with (II) isoamyl nitrite and (III) nitrous acid. The oxidation of morpholine by peroxynitrite in the presence and absence of added carbonate gives N-nitromorpholine and N-nitrosomorpholine. Nitration and nitrosation of morpholine are catalyzed by low levels of CO<sub>2</sub>; however, excess CO<sub>2</sub> dramatically reduces the yields of nitrosation but not nitration, and the combined yields of the products are about the same under conditions of high and low concentrations of CO<sub>2</sub>. These data indicate that both nitration and nitrosation by peroxynitrite are free radical processes. The morpholine radical, formed from the reactions of carbonate and/or hydroxyl radicals with morpholine, reacts with either <sup>•</sup>NO or <sup>•</sup>NO<sub>2</sub> and serves as a common precursor for both products. The peroxynitrite-mediated oxidation of &#945;-tocopherol and &#947;-tocopherol dispersed in 1,2-dilauroyl-<i>sn</i>-glycero-3-phosphocholine liposomes in the presence and absence of added carbonate gives &#945;-tocopherylquinone and 5-nitro-&#947;-tocopherol, respectively. The formation of the products is consistent with the current understanding of the free radical nature of oxidations of peroxynitrite and its CO<sub>2</sub>-adducts; the overall reaction involves a one-electron oxidation of &#945;-tocopherol and &#947;-tocopherol by HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, followed by the reaction with <sup>•</sup>NO<sub>2</sub>. When &#945;-tocopherol and &#947;-tocopherol were present in the same liposome and exposed to peroxynitrite, there was preferential oxidation of &#945;-tocopherol over &#947;-tocopherol. An explanation for the protection of &#947;-tocopherol by &#945;-tocopherol could be that &#947;- and &#945;-tocopheryl radicals, formed from the respective reactions of &#945;-tocopherol and &#947;-tocopherol with HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, disproportionate to give &#945;-tocopherylquinone and regenerated &#947;-tocopherol. This is consistent with the lack of protection of &#947;-tocopherol by &#945;-tocopherol when &#945;-tocopherol and &#947;-tocopherol dispersed in different liposomes but present in the same incubation mixer are subjected to oxidation by peroxynitrite."]},{"key":"dc:title","label":"Title","values":["Peroxynitrite-mediated oxidations: nitration and nitrosation"]}]}],"canonical_facts":{"dc:creator":["Bolzan, Rachel"],"dc:date":["2002-05-22"],"dc:date.available":["2022-05-12T23:08:35Z"],"dc:description.abstract":["Using a direct ultraviolet second-derivative spectroscopy method, three peroxynitrite preparative methods were investigated for the nitrite and nitrate present either as impurities or produced during peroxynitrite decomposition: (I) ozonation of azide, reaction of hydrogen peroxide with (II) isoamyl nitrite and (III) nitrous acid. The oxidation of morpholine by peroxynitrite in the presence and absence of added carbonate gives N-nitromorpholine and N-nitrosomorpholine. Nitration and nitrosation of morpholine are catalyzed by low levels of CO<sub>2</sub>; however, excess CO<sub>2</sub> dramatically reduces the yields of nitrosation but not nitration, and the combined yields of the products are about the same under conditions of high and low concentrations of CO<sub>2</sub>. These data indicate that both nitration and nitrosation by peroxynitrite are free radical processes. The morpholine radical, formed from the reactions of carbonate and/or hydroxyl radicals with morpholine, reacts with either <sup>•</sup>NO or <sup>•</sup>NO<sub>2</sub> and serves as a common precursor for both products. The peroxynitrite-mediated oxidation of &#945;-tocopherol and &#947;-tocopherol dispersed in 1,2-dilauroyl-<i>sn</i>-glycero-3-phosphocholine liposomes in the presence and absence of added carbonate gives &#945;-tocopherylquinone and 5-nitro-&#947;-tocopherol, respectively. The formation of the products is consistent with the current understanding of the free radical nature of oxidations of peroxynitrite and its CO<sub>2</sub>-adducts; the overall reaction involves a one-electron oxidation of &#945;-tocopherol and &#947;-tocopherol by HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, followed by the reaction with <sup>•</sup>NO<sub>2</sub>. When &#945;-tocopherol and &#947;-tocopherol were present in the same liposome and exposed to peroxynitrite, there was preferential oxidation of &#945;-tocopherol over &#947;-tocopherol. An explanation for the protection of &#947;-tocopherol by &#945;-tocopherol could be that &#947;- and &#945;-tocopheryl radicals, formed from the respective reactions of &#945;-tocopherol and &#947;-tocopherol with HO<sup>•</sup> or CO<sub>3</sub><sup>•-</sup>, disproportionate to give &#945;-tocopherylquinone and regenerated &#947;-tocopherol. This is consistent with the lack of protection of &#947;-tocopherol by &#945;-tocopherol when &#945;-tocopherol and &#947;-tocopherol dispersed in different liposomes but present in the same incubation mixer are subjected to oxidation by peroxynitrite."],"dc:identifier":["etd-0612102-234815","10.31390/gradschool_dissertations.366","https://repository.lsu.edu/gradschool_dissertations/366"],"dc:rights":["unrestricted","Release the entire work immediately for access worldwide."],"dc:subject":["mechanism"],"dc:title":["Peroxynitrite-mediated oxidations: nitration and nitrosation"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"],"thesis:institution_name":["Chemistry"]},"updated_at":"2026-07-24T02:57:30Z"}