Studies on plant cell cultures of Podophyllum Peltatum and Tripterygium Wilfordii for biosynthesis of biologically active compounds
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: Kuri-Brena, Francisco
issued: 2009-01-08T20:49:00Z
issued: 1992
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: This thesis investigates the use of plant cell cultures in combination with synthetic chemistry to provide new routes to biologically active compounds. The first chapter consists of approaches to the lignan podophyllotoxin (4), by means of enzyme catalyzed ring closure reactions of dibenzylbutyrolactone intermediates 56 and 57 mediated by Podophyllum peltatum cells. The substrates 56 and 57 studied were synthesized from readily available aromatic aldehydes employing a "one pot", 1,4addition- enolate alkylation sequence, as the key step. Semi-continuous biotransformation experiments performed with 56 illustrate the potential of the technique yielding the ring-closed products 75 and 76. A possible mechanism for the ring closure in vivo is provided, as well as suggestions to alter the stereochemical outcome of the process. The second chapter of this thesis concerns the attempts to oxidize dehydroisoabietanolide (132) with crude enzyme preparations (CFEs) from Tripterygium wilfordii, as part of an ongoing study regarding the biogenesis of the diterpcne triepoxides tripdiolide (5) and triptolide (91). The 12-hydroxy analogue of 132, isotriptophenolide (190), is also studied. Both compounds were prepared in gram quantities from dehydroabietic acid (122). The results from the biotransformation experiments, suggest that triptophenolide (163), an isomer of 190 and bearing a phenolic group at C-14, is a likely candidate for future biotransformation experiments. The present studies also suggest that an "activated" diterpene, that is, a substrate bearing a hydroxyl group in the aromatic ring (190 or an isomer), is a biogenetic precursor for the triepoxide system present in 5 and 91.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/3399
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note: S T U D I E S O N P L A N T C E L L C U L T U R E S O F P O D O P H Y L L U M P E L T A T U M A N D T R I P T E R Y G I U M W I L F O R D I I F O R B I O S Y N T H E S I S O F B I O L O G I C A L L Y A C T I V E C O M P O U N D S . by F R A N C I S C O K U R I - B R E N A B.Sc. (Chemistry), Universidad Nacional Autonoma de Mexico, 1985 M.Sc. (Chemistry), Universidad Nacional Autonoma de Mexico, 1987 A THESIS S U B M I T T E D I N P A R T I A L F U L F I L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E OF D O C T O R O F P H I L O S O P H Y in T H E F A C U L T Y O F G R A D U A T E STUDIES C H E M I S T R Y We accept this thesis as conforming to the required standard. T H E U N I V E R S I T Y OF B R I T I S H C O L U M B I A 26 August 1992 ® Francisco Kur i -Brena , 1992. In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Chemis t ry The University of British Columbia Vancouver, Canada Date Oc t . 1992 DE-6 (2/88) A B S T R A C T This thesis investigates the use of plant cell cultures in combination with synthetic chemistry to provide new routes to biologically active compounds. The first chapter consists of approaches to the lignan podophyllotoxin (4), by means of enzyme catalyzed ring closure reactions of dibenzylbutyrolactone intermediates 56 and 57 mediated by Podophyllum peltatum cells. The substrates 56 and 57 studied were synthesized from readily available aromatic aldehydes employing a "one pot", 1,4-addition-enolate alkylat ion sequence, as the key step. Semi-continuous b…
has type: Thesis/Dissertation
date issued: 1992-11
is shown at: 10.14288/1.0061736
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/3399