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.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1989

Author dc:creator

• Purvis, Michael Bernard

Chair dc:contributor.committeechair

• Kingston, David G. I.

Committee members dc:contributor.committeemember

• Bell, Harold M.
• White, Robert H.
• Dorn, Harry C.
• Lewis, N.G.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/54266

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/54266