{"id":{"repo_id":"sask","oai_identifier":"oai:harvest.usask.ca:10388/etd-05192010-134624"},"canonical_url":"https://search.dev.ndltd.org/etd/sask/oai:harvest.usask.ca:10388/etd-05192010-134624","repository":{"repo_id":"sask","name":"University of Saskatchewan","base_url":"https://harvest.usask.ca/server/oai/request"},"display":{"title":"Synthesis of analogues of nordihydroguaiaretic acid and their oxidative metabolism","abstract":"In order to investigate the structural features responsible for the cytotoxicity of the naturally occurring lignan nordihydroguaiaretic acid, the synthesis of four structural analogues of NDGA is proposed for the purpose of studying their oxidative metabolism. One analogue in particular (1), a mono-catechol analogue, is successfully synthesized employing a double Stobbe condensation approach. Following synthesis of this compound a series of oxidation experiments is performed consisting of: incubation in rat liver microsomes with and without the trapping agent glutathione (GSH), oxidation with mushroom tyrosinase, oxidation with silver oxide, and oxidation with horseradish peroxidase. Results are analyzed via HPLC and UPLC-MS. It is found that 1 does not autoxidize at pH 7.4 as NDGA does. Two products are produced during incubation of 1 in rat liver microsomes with UPLC-ESI(-)-MS results giving m/z of 879.2 and 574.18. This is consistent with 1 plus 2 GSH and 1 plus 1 GSH respectively; confirming 1 will oxidize to an electrophilic moiety. Oxidation with mushroom tyrosinase is found to produce high levels of product two with m/z 574.2. Oxidation with horseradish peroxidase is found to produce high levels of the m/z 879.2 product. Silver Oxide produced multiple products rather than the expected one major product, but most are found to be inconsistent with the products seen during rat liver microsomal incubation, and are not pursued.","abstract_html":"In order to investigate the structural features responsible for the cytotoxicity of the naturally occurring lignan nordihydroguaiaretic acid, the synthesis of four structural analogues of NDGA is proposed for the purpose of studying their oxidative metabolism. One analogue in particular (1), a mono-catechol analogue, is successfully synthesized employing a double Stobbe condensation approach. Following synthesis of this compound a series of oxidation experiments is performed consisting of: incubation in rat liver microsomes with and without the trapping agent glutathione (GSH), oxidation with mushroom tyrosinase, oxidation with silver oxide, and oxidation with horseradish peroxidase. Results are analyzed via HPLC and UPLC-MS. It is found that 1 does not autoxidize at pH 7.4 as NDGA does. Two products are produced during incubation of 1 in rat liver microsomes with UPLC-ESI(-)-MS results giving m/z of 879.2 and 574.18. This is consistent with 1 plus 2 GSH and 1 plus 1 GSH respectively; confirming 1 will oxidize to an electrophilic moiety. Oxidation with mushroom tyrosinase is found to produce high levels of product two with m/z 574.2. Oxidation with horseradish peroxidase is found to produce high levels of the m/z 879.2 product. Silver Oxide produced multiple products rather than the expected one major product, but most are found to be inconsistent with the products seen during rat liver microsomal incubation, and are not pursued.","abstract_has_math":false,"creators":["Maloney, Katherine Ann"],"institution":"University of Saskatchewan","degree_name":"Master of Science (M.Sc.)","degree_level":"Masters","degree_discipline":"Pharmacy","degree_department":null,"school":null,"contributors":[],"advisors":["Krol, Ed S."],"committee_chairs":[],"committee_members":["Berry, Mark","Palmer, David","Majewski, Marek","Alcorn, Jane"],"year":2010,"date_issued":"2010","date_published":"2010","updated_at":"2026-07-24T04:26:59Z","subjects":["cytochrome P450","bioactivation","reactive intermediate","lignan","anhydrosecoisolariciresinol","quinone","nordihydroguaiaretic acid","stobbe condensation","glutathione adduct"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10388/etd-05192010-134624","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Krol, Ed S."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Berry, Mark","Palmer, David","Majewski, Marek","Alcorn, Jane"]},{"key":"dc:creator","label":"Author","values":["Maloney, Katherine Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2010-05-19T13:46:24Z","2013-01-04T04:31:13Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2011-06-01T08:00:00Z","2013-01-04T04:31:13Z"]},{"key":"dc:date.issued","label":"Date","values":["2010"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Pharmacy"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (M.Sc.)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Saskatchewan"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["cytochrome P450","bioactivation","reactive intermediate","lignan","anhydrosecoisolariciresinol","quinone","nordihydroguaiaretic acid","stobbe condensation","glutathione adduct"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10388/etd-05192010-134624"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In order to investigate the structural features responsible for the cytotoxicity of the naturally occurring lignan nordihydroguaiaretic acid, the synthesis of four structural analogues of NDGA is proposed for the purpose of studying their oxidative metabolism. One analogue in particular (1), a mono-catechol analogue, is successfully synthesized employing a double Stobbe condensation approach. Following synthesis of this compound a series of oxidation experiments is performed consisting of: incubation in rat liver microsomes with and without the trapping agent glutathione (GSH), oxidation with mushroom tyrosinase, oxidation with silver oxide, and oxidation with horseradish peroxidase. Results are analyzed via HPLC and UPLC-MS. It is found that 1 does not autoxidize at pH 7.4 as NDGA does. Two products are produced during incubation of 1 in rat liver microsomes with UPLC-ESI(-)-MS results giving m/z of 879.2 and 574.18. This is consistent with 1 plus 2 GSH and 1 plus 1 GSH respectively; confirming 1 will oxidize to an electrophilic moiety. Oxidation with mushroom tyrosinase is found to produce high levels of product two with m/z 574.2. Oxidation with horseradish peroxidase is found to produce high levels of the m/z 879.2 product. Silver Oxide produced multiple products rather than the expected one major product, but most are found to be inconsistent with the products seen during rat liver microsomal incubation, and are not pursued."]},{"key":"dc:title","label":"Title","values":["Synthesis of analogues of nordihydroguaiaretic acid and their oxidative metabolism"]}]}],"canonical_facts":{"dc:contributor.advisor":["Krol, Ed S."],"dc:contributor.committeemember":["Berry, Mark","Palmer, David","Majewski, Marek","Alcorn, Jane"],"dc:creator":["Maloney, Katherine Ann"],"dc:date.accessioned":["2010-05-19T13:46:24Z","2013-01-04T04:31:13Z"],"dc:date.available":["2011-06-01T08:00:00Z","2013-01-04T04:31:13Z"],"dc:date.issued":["2010"],"dc:description.abstract":["In order to investigate the structural features responsible for the cytotoxicity of the naturally occurring lignan nordihydroguaiaretic acid, the synthesis of four structural analogues of NDGA is proposed for the purpose of studying their oxidative metabolism. One analogue in particular (1), a mono-catechol analogue, is successfully synthesized employing a double Stobbe condensation approach. Following synthesis of this compound a series of oxidation experiments is performed consisting of: incubation in rat liver microsomes with and without the trapping agent glutathione (GSH), oxidation with mushroom tyrosinase, oxidation with silver oxide, and oxidation with horseradish peroxidase. Results are analyzed via HPLC and UPLC-MS. It is found that 1 does not autoxidize at pH 7.4 as NDGA does. Two products are produced during incubation of 1 in rat liver microsomes with UPLC-ESI(-)-MS results giving m/z of 879.2 and 574.18. This is consistent with 1 plus 2 GSH and 1 plus 1 GSH respectively; confirming 1 will oxidize to an electrophilic moiety. Oxidation with mushroom tyrosinase is found to produce high levels of product two with m/z 574.2. Oxidation with horseradish peroxidase is found to produce high levels of the m/z 879.2 product. Silver Oxide produced multiple products rather than the expected one major product, but most are found to be inconsistent with the products seen during rat liver microsomal incubation, and are not pursued."],"dc:identifier.uri":["https://hdl.handle.net/10388/etd-05192010-134624"],"dc:language.iso":["en_US"],"dc:subject":["cytochrome P450","bioactivation","reactive intermediate","lignan","anhydrosecoisolariciresinol","quinone","nordihydroguaiaretic acid","stobbe condensation","glutathione adduct"],"dc:title":["Synthesis of analogues of nordihydroguaiaretic acid and their oxidative metabolism"],"thesis:degree_discipline":["Pharmacy"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science (M.Sc.)"],"thesis:institution_name":["University of Saskatchewan"]},"updated_at":"2026-07-24T04:26:59Z"}