{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/9975"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/9975","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Isolation of Natural Products from Casearia nigrescens","abstract":"As part of the continuing work of the International Cooperative Biodiversity Group (ICBG), plant extracts were received from Madagascar. The extracts were screened for cytotoxicity using the A2780 human ovarian cancer cell line bioassay. The crude extract of Casearia nigrescens was fractionated and yielded five known compounds and one new compound that were cytotoxic. Mass spectrometry and 1D and 2D NMR techniques were used to determine the structure of the isolated compounds. The dichloromethane fraction of Casearia nigrescens was weakly active in the A2780 human ovarian cancer cell line bioassay. Further separation of the dichloromethane fraction resulted in the isolation of five known compounds (casearlucin A, caseamenbrol A, rel-18(S),19(R)-diacetoxy-18,19-epoxy-6(R)-hydroxy-2(S)-(2ξ-methylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene, casearlucin B, and rel-18(S),19(R)-diacetoxy-18,19-epoxy-2(S)-(2ξ-ethylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene) and one new compound (casearlucin L). Based on the available literature this was the first investigation of the natural products of Casearia nigrescens. The structure of the known compounds was determined by comparison of the NMR, MS, optical rotation, UV, and IR data with the data found in the literature. The structure of casearlucin L was determined by NMR data and comparison with the NMR data for similar known compounds.","abstract_html":"As part of the continuing work of the International Cooperative Biodiversity Group (ICBG), plant extracts were received from Madagascar. The extracts were screened for cytotoxicity using the A2780 human ovarian cancer cell line bioassay. The crude extract of Casearia nigrescens was fractionated and yielded five known compounds and one new compound that were cytotoxic. Mass spectrometry and 1D and 2D NMR techniques were used to determine the structure of the isolated compounds. The dichloromethane fraction of Casearia nigrescens was weakly active in the A2780 human ovarian cancer cell line bioassay. Further separation of the dichloromethane fraction resulted in the isolation of five known compounds (casearlucin A, caseamenbrol A, rel-18(S),19(R)-diacetoxy-18,19-epoxy-6(R)-hydroxy-2(S)-(2ξ-methylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene, casearlucin B, and rel-18(S),19(R)-diacetoxy-18,19-epoxy-2(S)-(2ξ-ethylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene) and one new compound (casearlucin L). Based on the available literature this was the first investigation of the natural products of Casearia nigrescens. The structure of the known compounds was determined by comparison of the NMR, MS, optical rotation, UV, and IR data with the data found in the literature. The structure of casearlucin L was determined by NMR data and comparison with the NMR data for similar known compounds.","abstract_has_math":false,"creators":["Guza, Rebecca Clare"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Chemistry","degree_department":"Chemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Kingston, David G. I."],"committee_members":["Carlier, Paul R.","Long, Timothy E."],"year":2004,"date_issued":"2004-06-17","date_published":"2004-06-17","updated_at":"2026-07-22T22:20:00Z","subjects":["Casearia nigrescens","clerodane diterpenes","natural products"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06142004-174331"],"render_values":[{"text":"etd-06142004-174331","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/9975","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. I."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Carlier, Paul R.","Long, Timothy E."]},{"key":"dc:contributor.department","label":"Department","values":["Chemistry"]},{"key":"dc:creator","label":"Author","values":["Guza, Rebecca Clare"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2011-08-06T16:01:45Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2011-08-06T16:01:45Z","2004-06-30"]},{"key":"dc:date.issued","label":"Date","values":["2004-06-17"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Casearia nigrescens","clerodane diterpenes","natural products"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06142004-174331"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/9975"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["As part of the continuing work of the International Cooperative Biodiversity Group (ICBG), plant extracts were received from Madagascar. The extracts were screened for cytotoxicity using the A2780 human ovarian cancer cell line bioassay. The crude extract of Casearia nigrescens was fractionated and yielded five known compounds and one new compound that were cytotoxic. Mass spectrometry and 1D and 2D NMR techniques were used to determine the structure of the isolated compounds. The dichloromethane fraction of Casearia nigrescens was weakly active in the A2780 human ovarian cancer cell line bioassay. Further separation of the dichloromethane fraction resulted in the isolation of five known compounds (casearlucin A, caseamenbrol A, rel-18(S),19(R)-diacetoxy-18,19-epoxy-6(R)-hydroxy-2(S)-(2ξ-methylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene, casearlucin B, and rel-18(S),19(R)-diacetoxy-18,19-epoxy-2(S)-(2ξ-ethylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene) and one new compound (casearlucin L). Based on the available literature this was the first investigation of the natural products of Casearia nigrescens. The structure of the known compounds was determined by comparison of the NMR, MS, optical rotation, UV, and IR data with the data found in the literature. The structure of casearlucin L was determined by NMR data and comparison with the NMR data for similar known compounds."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Isolation of Natural Products from Casearia nigrescens"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Kingston, David G. I."],"dc:contributor.committeemember":["Carlier, Paul R.","Long, Timothy E."],"dc:contributor.department":["Chemistry"],"dc:creator":["Guza, Rebecca Clare"],"dc:date.accessioned":["2011-08-06T16:01:45Z"],"dc:date.available":["2011-08-06T16:01:45Z","2004-06-30"],"dc:date.issued":["2004-06-17"],"dc:description.abstract":["As part of the continuing work of the International Cooperative Biodiversity Group (ICBG), plant extracts were received from Madagascar. The extracts were screened for cytotoxicity using the A2780 human ovarian cancer cell line bioassay. The crude extract of Casearia nigrescens was fractionated and yielded five known compounds and one new compound that were cytotoxic. Mass spectrometry and 1D and 2D NMR techniques were used to determine the structure of the isolated compounds. The dichloromethane fraction of Casearia nigrescens was weakly active in the A2780 human ovarian cancer cell line bioassay. Further separation of the dichloromethane fraction resulted in the isolation of five known compounds (casearlucin A, caseamenbrol A, rel-18(S),19(R)-diacetoxy-18,19-epoxy-6(R)-hydroxy-2(S)-(2ξ-methylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene, casearlucin B, and rel-18(S),19(R)-diacetoxy-18,19-epoxy-2(S)-(2ξ-ethylbutanoyloxy)-5(R),8(S),9(S),10(R)-cleroda-3,13(16),14-triene) and one new compound (casearlucin L). Based on the available literature this was the first investigation of the natural products of Casearia nigrescens. The structure of the known compounds was determined by comparison of the NMR, MS, optical rotation, UV, and IR data with the data found in the literature. The structure of casearlucin L was determined by NMR data and comparison with the NMR data for similar known compounds."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["etd-06142004-174331"],"dc:identifier.uri":["http://hdl.handle.net/10919/9975"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Casearia nigrescens","clerodane diterpenes","natural products"],"dc:title":["Isolation of Natural Products from Casearia nigrescens"],"dc:type":["Thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:00Z"}