Search PubMed⌕ Search

Biomedical subjects

M Gorman

Publications and source records attributed to M Gorman.

At least 91 records · Page 5Linked to original sources
PubMed1970

Metabolism of tryptophan by Pseudomonas aureofaciens. 3. Production of substituted pyrrolnitrins from tryptophan analogues.

Exogenous tryptophan is metabolized by Pseudomonas aureofaciens to yield pyrrolnitrin [3-chloro-4-(2'-nitro-3'-chlorophenyl)-pyrrole], an antifungal agent. The ability of this culture to metabolize tryptophan analogues in a similar manner was investigated by addition of the appropriate compound to the fermentation. Tryptophan precursors and metabolites or nonphenyl-substituted tryptophans had little effect on pyrrolnitrin biosynthesis, but simple derivatives of indole inhibited the production of pyrrolnitrin. Tryptophans substituted at the 4 position decreased pyrrolnitrin production and were converted into the corresponding substituted indoles. Tryptophans substituted at the 5, 6, and 7 position with fluorine or at the 5 and 7 position with methyl yielded new pyrrolnitrin derivatives. Substitution of larger groups (such as chloro, bromo, trifluoromethyl, and methoxy) at these positions led to the formation of the intermediate, amino pyrrolnitrin [3-chloro-4-(2'-amino-3'-chlorophenyl)-pyrrole], with the appropriate new substituent. The trifluoromethyl group at the 6 position of tryptophan prevented chlorination at the 3 position of pyrrolnitrin.

Antifungal Agents↗
PubMed1969

Determination of pyrrolnitrin and derivatives by gas-liquid chromatography.

A gas-liquid chromatographic technique was applied to the separation of pyrrolnitrin and its derivatives. The simultaneous use of a flame detector and an electron capture detector made possible the distinction between the nitro derivatives of pyrrolnitrin and the other metabolites. The metabolites could be readily quantitated with the electron capture detector, offering a much more sensitive assay than the flame detector.

Antifungal Agents↗
PubMed1968

Metabolism of tryptophans by Pseudomonas aureofaciens. VI. Production of pyrrolnitrin by selected Pseudomonas species.

Twenty-nine strains of Pseudomonas, classified as P. fluorescens biotype D or E or as P. multivorans, were examined for the production of pyrrolnitrin, an antifungal agent synthesized in P. aureofaciens. Eight strains were shown to produce pyrrolnitrin in shake-flask fermentation. Four cultures were from the multivorans taxon, and the remaining four were members of the fluorescens group. The antifungal agent produced in these strains was isolated and shown to be pyrrolnitrin by comparison with an authentic sample. The strains differed markedly with respect to the amount of pyrrolnitrin produced and in their utilization of exogenous tryptophan. Secondary metabolites, not related to pyrrolnitrin, were also examined and compared with those synthesized in P. aureofaciens. Marked differences were noted in both phenazine pigments and phenolic metabolites. The results of the study suggest that the production of pyrrolnitrin may be widespread in selected taxonomic groups of Pseudomonas.

Antifungal Agents↗