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1
المؤلفون: Jack E. Baldwin, Christopher J. Schofield, Robert A. Field
المصدر: J. Chem. Soc., Chem. Commun.. :1531-1532
مصطلحات موضوعية: biology, Stereochemistry, viruses, ACV synthetase, virus diseases, chemistry.chemical_element, Oxygen, chemistry.chemical_compound, Biosynthesis, chemistry, Covalent bond, Valine, Cephalosporium acremonium, biology.protein, Molecular Medicine, skin and connective tissue diseases, Incubation
الوصف: Incubation of [18O2]valine with purified ACV synthetase from Cephalosporium acremonium gave exclusive incorporation of a single 18O label into δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV), consistent with the formation of a covalent valinoyl-ACV synthetase complex.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::660c48173b05701494828ab4748f780b
https://doi.org/10.1039/c39910001531 -
2
المؤلفون: Robin T. Aplin, Eeva-M. M. John, Leslie D. Field, Edward P. Abraham, Jack E. Baldwin, Robert M. Adlington, Robert L. White
المصدر: J. Chem. Soc., Chem. Commun.. :137-139
مصطلحات موضوعية: biology, Chemistry, Acremonium, Stereochemistry, Isopenicillin N, Cell free, Tripeptide, biology.organism_classification, Mass spectrometry, Valine, Cephalosporium acremonium, polycyclic compounds, Molecular Medicine, Incubation
الوصف: δ-(L-α-Amino[1,1,6-17O/18O]-adipyl)-L-cysteiny-D-valine was converted into isopenicillin N in cell-free extracts of Cephalosporium acremonium with no loss of 17O/18O label as shown by 17O n.m.r. spectroscopy and mass spectrometry; incubation of unlabelled tripeptide in cell-free system containing 17O/18O-enriched water produced isopenicillin N with no incorporation of 17O/18O.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::f10aef8487708cb480b6b684cd2ff6bc
https://doi.org/10.1039/c39820000137 -
3
المؤلفون: Hong-Hoi Ting, Sabine L. Flitsch, Nicholas J. Turner, Robert M. Adlington, Jack E. Baldwin
المصدر: J. Chem. Soc., Chem. Commun.. :1305-1308
مصطلحات موضوعية: inorganic chemicals, chemistry.chemical_classification, biology, Chemistry, Stereochemistry, Isopenicillin N synthase, Peptide, Cofactor, Enzyme, Oxygen atom, Cephalosporium acremonium, β lactams, polycyclic compounds, biology.protein, Molecular Medicine, Penicillin biosynthesis
الوصف: Two unsaturated peptide substrates were each cyclised by the enzyme isopenicillin N synthase (IPNS) from Cephalosporium acremonium CO 728 simultaneously to both desaturated and hydroxylated β-lactam products whose hydroxy groups have been shown to derive their oxygen atom from the cosubstrate dioxygen; a working hypothesis involving iron–oxo species is proposed to explain this phenomenon.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::0fa48a231f6a17b59ab2fb66851a7f15
https://doi.org/10.1039/c39860001305 -
4
المؤلفون: Masataka Fukumura, A. Ian Scott, Robert Baxter
المصدر: J. Chem. Soc., Chem. Commun.. :66-68
مصطلحات موضوعية: biology, Chemistry, Acremonium, Stereochemistry, Mutant, biology.organism_classification, law.invention, Hydrolysis, chemistry.chemical_compound, Biosynthesis, law, Valine, Molecular Medicine, Chirality (chemistry), Walden inversion
الوصف: (2S,3S)-[4-13C]Valine has been incorporated into the title compound (1) by a β-lactam negative mutant of Cephalosprium acremonium; isolation [as the corresponding sulphonic acid (1a) and subsequent hydrolysis afforded (2R,3S)-4-13C]valine, showing retention of the chirality at the 3-position.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::b121f39ef60047d9442a561a206e1799
https://doi.org/10.1039/c39820000066 -
5
المؤلفون: John J. Usher, Brian L. Johnson, Jack E. Baldwin, Robert L. White, Edward P. Abraham, Joyce A. Huddleston
المصدر: J. Chem. Soc., Chem. Commun.. :1271-1273
مصطلحات موضوعية: Chemistry, Stereochemistry, Valine, Isopenicillin N, Cephalosporium acremonium, polycyclic compounds, Molecular Medicine, Cell free
الوصف: Carbon-13 n.m.r. spectroscopy has been used to observe the efficient conversion of (L-α-amino-δ-adipyl)-L-cysteinyl-D-valine into isopenicillin N in cell-free extracts of Cephalosporium acremonium.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::4b5a841d597c6d269bc918611e64defd
https://doi.org/10.1039/c39800001271 -
6
المؤلفون: Robert Baxter, A. Ian Scott, Gordon A. Thomson
المصدر: J. Chem. Soc., Chem. Commun.. :32-34
مصطلحات موضوعية: chemistry.chemical_classification, biology, Stereochemistry, Isopenicillin N, Biological activity, Tripeptide, Amino acid, chemistry.chemical_compound, chemistry, Biosynthesis, Enzyme inhibitor, Valine, Cephalosporium acremonium, biology.protein, Molecular Medicine
الوصف: δ-(L-α-Aminoadipoly)-L-cysteinyl-N-hydroxy-D-valine (3a) has been prepared from the appropriately protected amino acids; (3a) was not converted into isopenicillin N (2) using a cell-free from Cephalosporium acremonium but inhibited the formation of (2) from δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (1) by this system.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::4d852709897765cb3905e3e920b6e81f
https://doi.org/10.1039/c39840000032 -
7
المصدر: J. Chem. Soc., Chem. Commun.. :984-986
مصطلحات موضوعية: Chemistry, Stereochemistry, Substrate (chemistry), Ring (chemistry), Penicillin, chemistry.chemical_compound, Biosynthesis, Biochemistry, Cephalosporium acremonium, Lactam, medicine, Molecular Medicine, Incubation, Penicillin biosynthesis, medicine.drug
الوصف: Incubation of a 1 : 1 mixture of δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (L,L,D-ACV) and L,L,D-A[3,3-2H2]CV with a cell-free extract of isopenicillin N synthetase from Cephalosporium acremonium results in preferential conversion of the fully protiated substrate into isopenicillin N; alternatively a similar experiment with a 1 : 1 mixture of L,L,D-ACV and L,L,D-AC[3-2H]V gave isopenicillin N without isotopic discrimination between the two substrates.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::c1f309eca00f65f8daaf3fae96a5466e
https://doi.org/10.1039/c39840000984 -
8
المؤلفون: Edward P. Abraham, Jack E. Baldwin, Robert L. White, Joyce A. Huddleston, Mankil Jung, John J. Usher
المصدر: J. Chem. Soc., Chem. Commun.. :246-247
مصطلحات موضوعية: biology, Chemistry, Acremonium, Stereochemistry, Valine, Cephalosporium acremonium, Isopenicillin N, Molecular Medicine, Tripeptide, Cell free, biology.organism_classification, Penicillin biosynthesis
الوصف: The tripeptide (L-α-amino-δ-adipyl)-L-cysteinyl-D-[22H, Me2–2H6]valine was converted into isopenicillin N by a cell-free extract ofCephalosporium acremonium;; complete retention of all deutrons was confirmed by 2H n.m.r. spectroscopy
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::2c981f91e4c368004f57ee8c17fe9da6
https://doi.org/10.1039/c39810000246 -
9
المؤلفون: Jack E. Baldwin, Joyce A. Huddleston, Terence Wan, Robert L. White, Edward P. Abraham, Mankil Jung, Gulam A. Bahadur
المصدر: J. Chem. Soc., Chem. Commun.. :1146-1147
مصطلحات موضوعية: chemistry.chemical_classification, Biochemistry, Stereochemistry, Chemistry, Isopenicillin N, Cephalosporium acremonium, Molecular Medicine, Peptide, Penicillin biosynthesis
الوصف: The two thiazepinone-containing peptides (5) and (7), as well as the β-hydroxyvaline peptide (3), have been synthesised and tested as substrates for isopenicillin N synthesis in a cell-free extract from Cephalosporium acremonium; none of these compounds behaved as substrates, in contradiction to a recent proposal.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::ab6a038fe865a1388527003120419479
https://doi.org/10.1039/c39810001146 -
10
المؤلفون: Edward P. Abraham, Max Lutstorf, Chi-Pui Pang, David H. G. Crout, Andrew E. Derome, Robert L. White, Phillip J. Morgan
المصدر: J. Chem. Soc., Chem. Commun.. :723-724
مصطلحات موضوعية: chemistry.chemical_compound, Stereospecificity, chemistry, Valine, Stereochemistry, Cephalosporium acremonium, polycyclic compounds, Molecular Medicine, Tritium, Cephalosporin C, Methylene, Methyl group
الوصف: Analysis by tritium n.m.r. has indicated that the incorporation or the pro-S methyl group of ‘chiral methyl valine’[as (1)] into the C-3′ exocyclic methylene group of cephalosporin C (5) in Cephalosporium acremonium occurs with at least 70% stereospecificity overall; in contrast, the tritium n.m.r. spectra obtained after the incorporation of pro-R methyl groups of opposite configuration into the C-2 methylene group of cephalosporin C were virtually identical, indicating that at some stage there is a common stereochemically identical intermediate.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::a9ccb21e6b468a59ccf5f3830c034161
https://doi.org/10.1039/c39830000723