Title page for ETD etd-11292012-040200
|Type of Document
||Pullockaran, Anie Jose
||Synthesis of labelled precursors of podophyllotoxin
||Master of Science
|Kingston, David G. I.
|Lewis, Norman G.
|Wolfe, James F.
|Date of Defense
Podophyllotoxin is an aryltetralin lignan and anticancer agent produced by the Podophyllum
and some other species and is extracted from Podophyllin in up to 30 percent yield. Little definitive
information is available on the biosynthetic pathways to podophyllotoxin. Administering various
specifically labelled precursors into intact plants and tissue cultures can give a much improved
insight into the lignan biogenesis. The first part of the work has been to the synthesis of two
diastereotopically labelled with 2H at C-4. Desoxypodophyllotoxin is the penultimate intermediate of
the podophyllotoxin pathway and specifically labelled compounds can be used for the C-4
hydroxylation studies. Doubly 2H labelled desoxypodophyllotoxin at C-4 was also prepared which
can be used for a control experiment. This work also led to the unambiguous assignment of the
proton nmr of desoxypodophyllotoxin. A second part of the work has been the synthesis of p-coumarlc acid, a known lignan precursor, doubly labeled with 2H or 2H and
at the C-3’ position.
This labeling was selected because the availability of a C-3’ labeled monomeric precursor would
thus make possible the isolation and study of dimeric compounds labeled at this key positions.
These compounds were synthesized, and their identity and stereochemistry were determined by
spectroscopic and analytical techniques. The isotopic incorporation of these compounds was 95%
d, or d2 (or greater), as determined by mass spectral analysis.
|| Approximate Download Time
| 28.8 Modem
|| 56K Modem
|| ISDN (64 Kb)
|| ISDN (128 Kb)
|| Higher-speed Access
next to an author's name indicates that all
files or directories associated with their ETD
are accessible from the Virginia Tech campus network only.
If you have questions or technical
problems, please Contact DLA.