Title page for ETD etd-06142004-174331

Type of Document Master's Thesis
Author Guza, Rebecca Clare
URN etd-06142004-174331
Title Isolation of Natural Products from Casearia nigrescens
Degree Master of Science
Department Chemistry
Advisory Committee
Advisor Name Title
Kingston, David G. I. Committee Chair
Carlier, Paul R. Committee Member
Long, Timothy E. Committee Member
  • Casearia nigrescens
  • clerodane diterpenes
  • natural products
Date of Defense 2004-06-14
Availability unrestricted
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)-(2î-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)-(2î-methylbutanoyloxy)-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.

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