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Biomedical subjects

H Vanderhaeghe

Publications and source records attributed to H Vanderhaeghe.

At least 55 records · Page 3Linked to original sources
PubMed1976

Incorporation of double-labelled valine into delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine by Penicillium chrysogenum.

The incorporation of valine into the LLD-tripeptide, delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine, a precursor of penicillin, was studied by incubating mycelial mats of Penicillium chrysogenum Wis. 49-2105 with double labelled valines. L-valine was incorporated into the LLD-tripeptide without formation of an alpha, beta-didehydrovaline intermediate. Intact D-valine was not incorporated into the LLD-tripeptide.

Carbon Radioisotopes↗
PubMed1975

Preparation and properties of 5-phenylphenoxymethylpenicillin.

Cycloaddition of azidoacetyl chloride to benzyl D-5,5-dimethyl-5-phenyl-2-thiazoline-4-carboxylate (1a) gave 5-phenyl-6alpha-azidopenicillanate (2a). By catalytic reduction of 2a and reaction with phenoxyacetyl chloride, 5-phenyl-6-epiphenoxymethylpenicillin benzyl ester (4a) was obtained. Oxidation of 4a gave the sulfoxide 6, which was isomerized in the presence of DBN. The sulfoxide 7 with the normal configuration could be isolated but deoxygenation of the sulfoxide was not successful. Isomerization of 4a with DBN, either with or without silylation of the side chain, gave a mixture from which 5-phenylphenoxymethylpenicillin benzyl ester (5) was isolated. Compound 5 was debenzylated to 5-phenylphenoxymethylpenicillin potassium salt (8). The antibacterial activity of 8 was low, whereas the 6-epimer 9 was inactive. Contary to published information, the 5-phenylpenam derivative 4c could be prepared by the same method.

Isomerism↗
PubMed1975

Incorporation of double-labeled L-cystine and DL-valine in penicillin.

l-[3,3'-(3)H]cystine was incorporated into penicillin with retention of one tritium. This result can be explained by beta-lactam formation through ring closure between C3 of cysteine and NH of valine. No radioactivity of dl-[2,3-(3)H]valine was incorporated into penicillin. The loss of isotope at C2 occurs during the inversion of configuration. The loss of label at C3 is discussed in terms of possible intermediates for the formation of the thiazolidine ring of penicillin.

Carbon Radioisotopes↗
PubMed1975

Presence of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine in fermentations of Penicillium chrysogenum.

Cultures of Penicillium chrysogenum, growth with [(35)S]sulfate or labeled amino acids, were examined by ion-exchange chromatography for possible peptidic precursors of penicillin. A sulfur-containing compound, present in both the mycelial extracts and the culture filtrates, was eluted at the location of the synthetic lld-tripeptide delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine. Since this compound was also labeled when the cultures were incubated with dl-[6-(14)C]alpha-aminoadipic acid, l-[3,3'-(3)H]cystine, or dl-[1-(14)C]valine, its identity with the synthetic lld-tripeptide can be accepted. No delta-(l-alpha-aminoadipyl)-l-cysteine or lll-tripeptide were detected. The implications of these findings for tripeptide and penicillin biosynthesis are discussed.

Culture Media↗