{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/40067"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/40067","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Structural and synthetic studies of bioactive natural products","abstract":"Bioassay directed fractionation of the methyl ethyl ketone extract of Crescentia cujete resulted in the isolation of nine bioactive compounds, and detailed spectroscopic interpretation led to the assignment of their structures as (2S,3S)-3-hydroxy-5,6-dimethoxy dehydroiso-α-Iapachone [2.10], (2R)-5,6- dimethoxydehydroiso-α-Iapachone [2.11], (2R)-5-methoxy dehydroiso-alapachone [2.12], 5-hydroxy-2-(1'-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.13], 2-(1 '-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.14]' 2-isopropenylnaphtho[ 2,3-b ]furan-4,9-dione [2.15], 5-hydroxydehydro-iso-a-Iapachone [2.16], 3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.17], and 9- hydroxy-3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.18]. Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system. The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from <i>Pseudobersama mossambicensis</i>, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed.","abstract_html":"Bioassay directed fractionation of the methyl ethyl ketone extract of Crescentia cujete resulted in the isolation of nine bioactive compounds, and detailed spectroscopic interpretation led to the assignment of their structures as (2S,3S)-3-hydroxy-5,6-dimethoxy dehydroiso-α-Iapachone [2.10], (2R)-5,6- dimethoxydehydroiso-α-Iapachone [2.11], (2R)-5-methoxy dehydroiso-alapachone [2.12], 5-hydroxy-2-(1&#x27;-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.13], 2-(1 &#x27;-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.14]&#x27; 2-isopropenylnaphtho[ 2,3-b ]furan-4,9-dione [2.15], 5-hydroxydehydro-iso-a-Iapachone [2.16], 3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.17], and 9- hydroxy-3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.18]. Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system. The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from &lt;i&gt;Pseudobersama mossambicensis&lt;/i&gt;, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed.","abstract_has_math":false,"creators":["Heltzel, Carl E."],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Chemistry","degree_department":"Chemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Kingston, David G. I."],"committee_members":["Bell, Harold M.","Castagnoli, Neal Jr.","Merola, Joseph S.","Taylor, Larry T."],"year":1993,"date_issued":"1993-10-26","date_published":"1993-10-26","updated_at":"2026-07-22T22:20:31Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-10212005-123005"],"render_values":[{"text":"etd-10212005-123005","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/40067","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Kingston, David G. 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Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system. The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from <i>Pseudobersama mossambicensis</i>, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Structural and synthetic studies of bioactive natural products"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Kingston, David G. I."],"dc:contributor.committeemember":["Bell, Harold M.","Castagnoli, Neal Jr.","Merola, Joseph S.","Taylor, Larry T."],"dc:contributor.department":["Chemistry"],"dc:creator":["Heltzel, Carl E."],"dc:date.accessioned":["2014-03-14T21:21:55Z"],"dc:date.available":["2014-03-14T21:21:55Z","2005-10-21"],"dc:date.issued":["1993-10-26"],"dc:description.abstract":["Bioassay directed fractionation of the methyl ethyl ketone extract of Crescentia cujete resulted in the isolation of nine bioactive compounds, and detailed spectroscopic interpretation led to the assignment of their structures as (2S,3S)-3-hydroxy-5,6-dimethoxy dehydroiso-α-Iapachone [2.10], (2R)-5,6- dimethoxydehydroiso-α-Iapachone [2.11], (2R)-5-methoxy dehydroiso-alapachone [2.12], 5-hydroxy-2-(1'-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.13], 2-(1 '-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.14]' 2-isopropenylnaphtho[ 2,3-b ]furan-4,9-dione [2.15], 5-hydroxydehydro-iso-a-Iapachone [2.16], 3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.17], and 9- hydroxy-3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.18]. Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system. The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from <i>Pseudobersama mossambicensis</i>, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed."],"dc:description.degree":["Ph. D."],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-10212005-123005"],"dc:identifier.uri":["http://hdl.handle.net/10919/40067"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Structural and synthetic studies of bioactive natural products"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:31Z"}