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Stereochemical aspects of virginiamycin biosynthesis: biosynthesis of antibiotic A33853

The biochemical pathways for the formation of the unusual amino acids found in virginiamycin M₁ and A33853 were investigated. Specifically tritiated and carbon 14 labeled serines were incorporated into virginiamycin M₁. (2S)-serine and (2S,3R)-[3-³H] serine were found to be precursors, thus giving evidence of stereochemical control in the formation of the oxazole moiety. This information allowed for postulation of a ring closure pathway. Stereochemical investigations were also carried out on the dehydroproline unit and it was shown that both (R) and (S) prolines were incorporated into the dehydroproline unit. (2S,3R)-[3-³H] proline was synthesized and upon incorporation lost the (3-³H) label as evidence of stereochemical control in the formation of the dehydroproline unit from a saturated precursor.

The basic biosynthetic origins of A33853 were investigated by feeding of D-[U-¹⁴C] glucose, sodium [U-¹⁴C] acetate, (S)-[U-¹⁴C] lysine, (S)-[U-¹⁴C] aspartic acid, [carboxyl-¹⁴C] anthranilic acid, and (S)-[5-³H] tryptophan. D-[U-¹⁴C]. Glucose and (S)-[U-¹⁴C] lysine appeared to be the main precursors. ¹³C¹⁵N lysine was synthesized and used to examine the ring closure of the 3-hydroxypicolinic amide ring in virginiamycin S₁. / Ph. D.

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/54266
Date January 1989
CreatorsPurvis, Michael Bernard
ContributorsChemistry, Kingston, David G. I., Bell, Harold M., White, Robert H., Dorn, Harry C., Lewis, N.G.
PublisherVirginia Polytechnic Institute and State University
Source SetsVirginia Tech Theses and Dissertation
Languageen_US
Detected LanguageEnglish
TypeDissertation, Text
Formatxvii, 200 leaves, application/pdf, application/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/
RelationOCLC# 20139789

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