Aspects of natural product chemistry: Biosynthesis, structure elucidation and HSCCC/MBI/FABMS
McGuire, James Norton
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/20994
Description
Title
Aspects of natural product chemistry: Biosynthesis, structure elucidation and HSCCC/MBI/FABMS
Author(s)
McGuire, James Norton
Issue Date
1996
Doctoral Committee Chair(s)
Rinehart, Kenneth L., Jr.
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Chemistry, Analytical
Chemistry, Organic
Chemistry, Pharmaceutical
Language
eng
Abstract
The structure and biosynthesis of cremeomycin, a novel cytotoxic antibiotic from Streptomyces cremeus NRRL 3241, were established. Cremeomycin was found to be 3-diazo-4-methoxycyclohexa-4,6-dien-2-one carboxylic acid by X-ray crystallography. Through the intermediacy of 4-methoxysalicylic acid, cremeomycin was shown to be biosynthesized by a $\rm C\sb2+C\sb2+C\sb3$ pathway in contrast to 3-amino-5-hydroxybenzoic acid and 3-aminobenzoic acid, which are made by variants of the shikimic acid pathway. Incorporation of (1-$\sp{13}$C) - scD-glucose, (6-$\sp{13}$C) - scD-glucose, (U-$\sp{13}$C$\sb6\rbrack$- scD-glucose, (1,2-$\rm\sp{13}C\sb2$) -acetate and (2-$\sp{13}$C) -acetate revealed that the C$\sb3$ piece was labeled by glucose most likely through glycolysis. The C$\sb2$ portions were found to be constructed of acetate and assembled in a tail-tail fashion as from the citric acid cycle. Two putative intermediates, (3,5-$\rm\sp2H\sb2$) -2,4-dihydroxybenzoic acid and (5-$\sp2$H) -3-amino-4-hydroxybenzoic acid, were synthesized, but were not incorporated.
A system for on-line detection in high-speed countercurrent chromatography using fast atom bombardment mass spectrometry through a moving belt interface (HSCCC/MBI/FABMS) was assembled. Analytes that are normally difficult to see by optical methods were detected by the mass spectrometer and identified using the resulting structural information. The MBI displayed advantages over thermospray and frit FAB (also CF-FAB) with respect to back-pressure and flow-rate compatibility, respectively. Furthermore, the MBI did not require the addition of a FAB matrix, which can sometimes adversely affect chromatographic separations.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.