The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by growing a teicoplanin ... more The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by growing a teicoplanin producing strain of Actinoplanes teichomyceticus (ATCC 31121) on glucose containing either 34.0% [1-(13)C]glucose or 9.7% [U-(13)C]glucose. The fractional enrichment pattern of teicoplanin produced in the medium containing [1-(13)C]glucose was obtained from a one-dimensional (13)C spectrum. The enrichment pattern showed characteristic peaks indicating that amino acids 3 and 7 are derived from acetate, whereas amino acids 1, 2, 4, 5, and 6 are derived from tyrosine. Multiplet structures in heteronuclear single quantum coherence spectra of teicoplanin produced in the medium containing [U-(13)C]glucose showed characteristic coupling patterns supporting these results. Fractional enrichment patterns and multiplet structures of the three sugars in teicoplanin showed that about 50% of the sugars have the same labeling pattern as the glucose substrate whereas the rest have a labeling pattern showing that they are reassembled, probably from precursors in the primary metabolism.
... Uffe Anthonia, Klaus Bockb, Carsten Christophersena', Jens 0. Duusb, Eva Bie Kjsere, and ... more ... Uffe Anthonia, Klaus Bockb, Carsten Christophersena', Jens 0. Duusb, Eva Bie Kjsere, and Per H. Nielsena a. Marine Chemistry Section, The HC sted Institute, University of Copenhagen, Universitetsparken 5, DK2100 ... References and Notes d Cr 1. DJ Faulkner, J. Nat. Prod. ...
... Subramaniam Sabesan,* Jens 0. DUUS , ~ ~ ~ Susana Neira, Peter Domaille, Serrge Kelm,§ James ... more ... Subramaniam Sabesan,* Jens 0. DUUS , ~ ~ ~ Susana Neira, Peter Domaille, Serrge Kelm,§ James C. Paulson," and Klaus Bock1 ... Understanding the mechanism of such a carbohydrate-protein interaction may provide us with a clue to promote or prevent a biological reaction of ...
Deamination of LPSs from Klebsiella pneumoniae released O-chain polysaccharides together with a f... more Deamination of LPSs from Klebsiella pneumoniae released O-chain polysaccharides together with a fragment of the core oligosaccharide. The structures of the products from serotypes O1, O2a, O2a,c, O3, O4, O5, and O12 were determined by NMR spectroscopy and chemical methods, identifying the linkage region between the O antigens and the core as well as novel residues at the non-reducing ends of the polysaccharides. All serotypes had an identical linkage between the O chain and core.
The novel compound lumpidin (1) has been isolated as a major compound from an isolate of Penicill... more The novel compound lumpidin (1) has been isolated as a major compound from an isolate of Penicillium nordicum. Compound 1 is a diketopiperazine with a unique ring system likely to be a condensate of one mole each of L-tryptophan, L-phenylalanine, and L-homo-proline. The fact that 1 has been detected from only three out of sixteen isolates of P. nordicum indicates that lumpidin-producing isolates might represent a separate and third ochratoxin A producing Penicillium species.
Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YE... more Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YES). Cultivation of fungal cultures on solid medium allowed the isolation of two novel tryptoquivaline-like metabolites, tryptoquialanine A (1) and tryptoquialanine B (2), also biosynthesized on citrus fruits. Their structural elucidation is described on the basis of their spectroscopic data, including those from 2D NMR experiments. The analysis of the biomass sterols led to the identification of 8-12. Fungal infection on the natural substrates induced the release of citrus monoterpenes together with fungal volatiles. The host-pathogen interaction in nature and the possible biological role of citrus volatiles are also discussed.
The yellow brain mushroom Tremella mesenterica possesses a wide spectrum of medicinal properties,... more The yellow brain mushroom Tremella mesenterica possesses a wide spectrum of medicinal properties, including immunostimulating, protecting against radiation, antidiabetic, anti-inflammatory, hypocholesterolemic, hepatoprotective, and antiallergic effects. A unique feature of T. mesenterica is that most of the above mentioned medicinal properties depend on glucuronoxylomannan (GXM) contained in fruiting bodies or produced in pure culture conditions. We developed a new strain of T. mesenterica CBS 101939, which grows in submerged culture and offers superior yields of one-cell biomass rich in exocellular heteropolysaccharide GXM. The structure of the GXM was analyzed by NMR spectroscopy and chemical methods. The polysaccharide has a defined repeating unit structure, which is O-acetylated at several points: [structure: see text]. These results differ from previously published structure of Tremella extracellular polysaccharides, where mannan backbone was believed to be randomly glycosylated with xylan chains of different length.
The structure of the LPS from Serratia marcescens serotype O19 was investigated. Deamination of t... more The structure of the LPS from Serratia marcescens serotype O19 was investigated. Deamination of the LPS released the O-chain polysaccharide together with a fragment of the core oligosaccharide. The following structure of the product was determined by NMR spectroscopy, mass spectrometry, and chemical methods: [carbohydrate structure: see text] The main polymer consists of a repeating disaccharide V-U and is present on average of 18 units per chain as estimated by integration of signals in the NMR spectra. The residue O corresponds to the primer, which initiates biosynthesis of the O-chain, and an oligomer of a disaccharide R-S is an insert between the primer and the main polymer. The polysaccharide has a beta-Kdo residue at the non-reducing end, a feature similar to that observed previously in the LPS from Klebsiella O12.
Journal of the Chemical Society Perkin Transactions 1
A panel of alpha-helical, dimeric coiled-coil peptides has been designed and synthesized for the ... more A panel of alpha-helical, dimeric coiled-coil peptides has been designed and synthesized for the evaluation of the effect of glycosylation on the conformation of these coiled-coil peptides, Two glycosylated building blocks, N-alpha-(fluoren-9-ylmethoxycarbonyl)-O-(2,3,4-tri-O-acetyl-6-axido-6-deoxy-beta-D-glucopyranosyl)-L-threonine pentafluorophenyl ester 8 and N-alpha-(fluoren-9-ylmethoxycarbonyl)-O-{2,3,4-tri-O-acetyl-6-[2'-(tert-butoxycarbonylamino)benzoylamino]-6-deoxy-beta-D-glucopyranosyl}-L-theronine pentafluorophenyl ester 9 containing the fluorogenic 2-aminobenzamide (Abz) group, have been synthesized, These compounds have been obtained by the glycosylation of N-alpha-Fmoc-Thr-OPfp with the corresponding glycosyl trichloroacetimidate donors and have been incorporated into the solid-phase synthesis of the peptides 1-3 and 7 and glycopeptides 4-6, Compounds 1 and 4-7 have been synthesized as internally quenched fluorogenic compounds where the Abz group has been employed ...
The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by growing a teicoplanin ... more The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by growing a teicoplanin producing strain of Actinoplanes teichomyceticus (ATCC 31121) on glucose containing either 34.0% [1-(13)C]glucose or 9.7% [U-(13)C]glucose. The fractional enrichment pattern of teicoplanin produced in the medium containing [1-(13)C]glucose was obtained from a one-dimensional (13)C spectrum. The enrichment pattern showed characteristic peaks indicating that amino acids 3 and 7 are derived from acetate, whereas amino acids 1, 2, 4, 5, and 6 are derived from tyrosine. Multiplet structures in heteronuclear single quantum coherence spectra of teicoplanin produced in the medium containing [U-(13)C]glucose showed characteristic coupling patterns supporting these results. Fractional enrichment patterns and multiplet structures of the three sugars in teicoplanin showed that about 50% of the sugars have the same labeling pattern as the glucose substrate whereas the rest have a labeling pattern showing that they are reassembled, probably from precursors in the primary metabolism.
... Uffe Anthonia, Klaus Bockb, Carsten Christophersena', Jens 0. Duusb, Eva Bie Kjsere, and ... more ... Uffe Anthonia, Klaus Bockb, Carsten Christophersena', Jens 0. Duusb, Eva Bie Kjsere, and Per H. Nielsena a. Marine Chemistry Section, The HC sted Institute, University of Copenhagen, Universitetsparken 5, DK2100 ... References and Notes d Cr 1. DJ Faulkner, J. Nat. Prod. ...
... Subramaniam Sabesan,* Jens 0. DUUS , ~ ~ ~ Susana Neira, Peter Domaille, Serrge Kelm,§ James ... more ... Subramaniam Sabesan,* Jens 0. DUUS , ~ ~ ~ Susana Neira, Peter Domaille, Serrge Kelm,§ James C. Paulson," and Klaus Bock1 ... Understanding the mechanism of such a carbohydrate-protein interaction may provide us with a clue to promote or prevent a biological reaction of ...
Deamination of LPSs from Klebsiella pneumoniae released O-chain polysaccharides together with a f... more Deamination of LPSs from Klebsiella pneumoniae released O-chain polysaccharides together with a fragment of the core oligosaccharide. The structures of the products from serotypes O1, O2a, O2a,c, O3, O4, O5, and O12 were determined by NMR spectroscopy and chemical methods, identifying the linkage region between the O antigens and the core as well as novel residues at the non-reducing ends of the polysaccharides. All serotypes had an identical linkage between the O chain and core.
The novel compound lumpidin (1) has been isolated as a major compound from an isolate of Penicill... more The novel compound lumpidin (1) has been isolated as a major compound from an isolate of Penicillium nordicum. Compound 1 is a diketopiperazine with a unique ring system likely to be a condensate of one mole each of L-tryptophan, L-phenylalanine, and L-homo-proline. The fact that 1 has been detected from only three out of sixteen isolates of P. nordicum indicates that lumpidin-producing isolates might represent a separate and third ochratoxin A producing Penicillium species.
Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YE... more Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YES). Cultivation of fungal cultures on solid medium allowed the isolation of two novel tryptoquivaline-like metabolites, tryptoquialanine A (1) and tryptoquialanine B (2), also biosynthesized on citrus fruits. Their structural elucidation is described on the basis of their spectroscopic data, including those from 2D NMR experiments. The analysis of the biomass sterols led to the identification of 8-12. Fungal infection on the natural substrates induced the release of citrus monoterpenes together with fungal volatiles. The host-pathogen interaction in nature and the possible biological role of citrus volatiles are also discussed.
The yellow brain mushroom Tremella mesenterica possesses a wide spectrum of medicinal properties,... more The yellow brain mushroom Tremella mesenterica possesses a wide spectrum of medicinal properties, including immunostimulating, protecting against radiation, antidiabetic, anti-inflammatory, hypocholesterolemic, hepatoprotective, and antiallergic effects. A unique feature of T. mesenterica is that most of the above mentioned medicinal properties depend on glucuronoxylomannan (GXM) contained in fruiting bodies or produced in pure culture conditions. We developed a new strain of T. mesenterica CBS 101939, which grows in submerged culture and offers superior yields of one-cell biomass rich in exocellular heteropolysaccharide GXM. The structure of the GXM was analyzed by NMR spectroscopy and chemical methods. The polysaccharide has a defined repeating unit structure, which is O-acetylated at several points: [structure: see text]. These results differ from previously published structure of Tremella extracellular polysaccharides, where mannan backbone was believed to be randomly glycosylated with xylan chains of different length.
The structure of the LPS from Serratia marcescens serotype O19 was investigated. Deamination of t... more The structure of the LPS from Serratia marcescens serotype O19 was investigated. Deamination of the LPS released the O-chain polysaccharide together with a fragment of the core oligosaccharide. The following structure of the product was determined by NMR spectroscopy, mass spectrometry, and chemical methods: [carbohydrate structure: see text] The main polymer consists of a repeating disaccharide V-U and is present on average of 18 units per chain as estimated by integration of signals in the NMR spectra. The residue O corresponds to the primer, which initiates biosynthesis of the O-chain, and an oligomer of a disaccharide R-S is an insert between the primer and the main polymer. The polysaccharide has a beta-Kdo residue at the non-reducing end, a feature similar to that observed previously in the LPS from Klebsiella O12.
Journal of the Chemical Society Perkin Transactions 1
A panel of alpha-helical, dimeric coiled-coil peptides has been designed and synthesized for the ... more A panel of alpha-helical, dimeric coiled-coil peptides has been designed and synthesized for the evaluation of the effect of glycosylation on the conformation of these coiled-coil peptides, Two glycosylated building blocks, N-alpha-(fluoren-9-ylmethoxycarbonyl)-O-(2,3,4-tri-O-acetyl-6-axido-6-deoxy-beta-D-glucopyranosyl)-L-threonine pentafluorophenyl ester 8 and N-alpha-(fluoren-9-ylmethoxycarbonyl)-O-{2,3,4-tri-O-acetyl-6-[2'-(tert-butoxycarbonylamino)benzoylamino]-6-deoxy-beta-D-glucopyranosyl}-L-theronine pentafluorophenyl ester 9 containing the fluorogenic 2-aminobenzamide (Abz) group, have been synthesized, These compounds have been obtained by the glycosylation of N-alpha-Fmoc-Thr-OPfp with the corresponding glycosyl trichloroacetimidate donors and have been incorporated into the solid-phase synthesis of the peptides 1-3 and 7 and glycopeptides 4-6, Compounds 1 and 4-7 have been synthesized as internally quenched fluorogenic compounds where the Abz group has been employed ...
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