Short synthesis of parabactin

Bergeron, Raymond J.; Kline, Steven J.

doi:10.1021/ja00380a032

Cited by 46 publications

(33 citation statements)

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“…For the synthesis of agrobactin [154] and parabactin [155] (Figure 28), the diprotected triamine spermidine (from the synthetic scheme shown in Figure 27) is treated briefly with trifluoroacetic acid to yield spermidine, benzylated at the secondary amine function. This is reacted with 2,3-dimethoxybenzoylchloride to the diamide.…”

Section: Chemical Synthesismentioning

confidence: 99%

Peptide siderophores

1998

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Siderophores are low molecular weight iron chelators, produced by virtually all bacteria, fungi and some plants. They serve to deliver the essential element iron, barely soluble under aerobic conditions, into microbial cells. Siderophores are therefore important secondary metabolites which are very often based on amino acids and their derivatives. Biosynthesis, transport, regulation and chemical synthesis of natural siderophores and their analogues is of considerable interest for the protein and peptide chemist. This review gives an overview of the structural classes of peptidic siderophores, along with data on their biosynthesis. On a number of representative examples, strategies and schemes of their chemical synthesis are described.

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Section: Chemical Synthesismentioning

confidence: 99%

Peptide siderophores

1998

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“…Interestingly, the siderophores isolated from both Rhodococcus and Nocardia are in many ways similar to the ligands predicated on polyamine backbones, e.g., parabactin 9 and agrobactin 14 (Figure 2). For example, with parabactin, the bidentate fragments, 2,3-dihydroxybenzoyl groups, are fixed to a linear polyamine backbone at the terminal nitrogens via amide linkages.…”

Section: Introductionmentioning

confidence: 98%

“…These particular ligands form 1:1 complexes with Fe(III). Catecholamide chelators typically form tighter Fe(III) complexes, e.g., parabactin 9 (K f = 10 48 M −1 ) (Figure 2), than their hydroxamate counterparts, e.g., desferrioxamine (10 28 M −1 ) (Figure 1). 10 …”

Section: Introductionmentioning

confidence: 99%

Synthesis of heterobactins A and B and Nocardia heterobactin

2011

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The synthesis of the Rhodococcus erythropolis siderophores heterobactins A and B, and the structurally related Nocardia heterobactin, is described. Two approaches for the assembly of these asymmetric ligand donor chelators are explored. In the first approach, a scheme predicated on the biosynthesis of the Paracoccus denitrificans siderophore, parabactin, is employed. In this approach, the central donor synthon is added last. In the second scheme, the central donor and the terminal 2,3-dihydroxybenzoyl fragment are first fixed to the ligand’s D-ornithine backbone. This is followed by condensation with the cyclic ornithine hydroxamate glycine segment. The schemes offer a flexible approach to other heterobactins. Job’s plots suggest that heterobactin A and Nocardia heterobactin form 1:1 ligand/metal complexes, while heterobactin B forms a 3:2 ligand/metal complex.

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“…55FeCl3 (specific activity, 43.57 Ci g-1) in 0.5 M HCI and Biofluor Scintillation Cocktail were purchased from Du Pont, NEN Research Products. Desferrioxamines B and E were gifts from CIBA-GEIGY Corp. L-Agrobactin (8), L-agrobactin A (9), L-homoparabactin (6), and L-vibriobactin (5) were synthesized as previously reported. D-Parabactin and D-parabactin A were synthesized and purified in a manner identical to that for the corresponding L-enantiomers, but with N-tert-butoxycarbonyl-D-threonine (BOC-D-Thr) instead of BOC-L-Thr (3,4).…”

Section: Methodsmentioning

confidence: 99%

Kinetics of iron acquisition from ferric siderophores by Paracoccus denitrificans

Bergeron

Weimar

1990

J Bacteriol

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The kinetics of iron accumulation by iron-starved Paracoccus denitrificans during the first 2 min of exposure to "5Fe-labeled ferric siderophore chelates is described. Iron is acquired from the ferric chelate of the natural siderophore L-parabactin in a process exhibiting biphastic kinetics by Lineweaver-Burk analysis. The kinetic data for 1 ,uM < [Fe L-parabactin] < 10 ,uM fit a regression line which suggests a low-affinity system (Km = 3.9 ± 1.2 ,uM, Vma,,j = 494 pg-atoms of 55Fe min-' mg of protein-'), whereas the data for 0.1 5AM < [Fe L-parabactin] c 1 1AM fit another line consistent with a high-affinity system (Km = 0.24 ± 0.06 ,uM, Vmax = 108 pg-atoms of 55Fe min'-mg of protein-l). The Km of the high-affinity uptake is comparable to the binding affinity we had previously reported for the purified ferric L-parabactin receptor protein in the outer membrane. In marked contrast, ferric D-parabactin data fit a single regression line corresponding to a simple MichaelisMenten process with comparatively low affinity (Km = 3.1 ± 0.9 ,uM, Vmax = 125 pg-atoms of 55Fe min-' mg of protein-'). Other catecholamide siderophores with an intact oxazoline ring derived from L-threonine (L-homoparabactin, L-agrobactin, and L-vibriobactin) also exhibit biphasic kinetics with a high-affinity component similar to ferric L-parabactin. Circular dichroism confirmed that these ferric chelates, like ferric L-parabactin, exist as the A enantiomers. The A forms of ferric parabactin (ferric D-and L-parabactin A), in which the oxazoline ring is hydrolyzed to the open-chain threonyl structure, exhibit linear kinetics with a comparatively high Km (1.4 ± 0.3 1AM) and high Vmax (324 pg-atoms of 55Fe min-' mg of protein-').Furthermore, the marked stereospecificity seen between ferric D-and L-parabactins is absent; i.e., iron acquisition from ferric parabactin A is nonstereospecific. The mechanistic implications of these findings in relation to a stereospecific high-affinity binding followed by a nonstereospecific postreceptor processing is discussed.The gram-negative soil bacterium Paracoccus denitrificans excretes a hexacoordinate catecholamide iron chelator, a siderophore, parabactin ( Fig. 1) (36, 42). The five aromatic hydroxyls and the oxazoline ring nitrogen of this ligand have been implicated as the donor centers coordinated to iron in the ferric L-parabactin-chelate complex (34). Previously we demonstrated that the kinetics of iron incorporation by P. denitrificans grown in iron-deficient media is consistent with an "iron taxi" mechanism (4). In the mechanism envisaged, the ferric siderophore binds to a specific receptor protein in the outer membrane, with subsequent release of iron from the siderophore complex while still on the extracellular side of the inner cytoplasmic membrane. The released iron is then transported into the cell, while the deferrated ligand remains extracellular where it may be reused for iron transport. We have identified, isolated, and partially purified a stereospecific high-affinity receptor for ferric L-para...

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Short synthesis of parabactin

Cited by 46 publications

References 0 publications

Peptide siderophores

Peptide siderophores

Synthesis of heterobactins A and B and Nocardia heterobactin

Kinetics of iron acquisition from ferric siderophores by Paracoccus denitrificans

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