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ABSTRACT: The crystal structure of crassin p-iodobenzoate has been determined by the heavy-atom technique and refined by the least-squares method using three dimensional intensity data. The crystal is monoclinic with cell dimensions: a = 6.492 ± 0.002, b = 18.098 ± 0.006, c = 11.209 ± 0.004 Å, β = 97.1° ± 0.1°, with Z = 2; space group P21. The absolute configuration of the crassin molecule has been determined by using the anomalous dispersion of the iodine atom and the stereochemistry of the molecule has been confirmed. The molecule is found to consist of a 14-membered cembrane ring fused with a δ-lactone.
Recueil des Travaux Chimiques des Pays-Bas. 09/2010; 88(12):1413 - 1423.
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04/2002;
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ABSTRACT: The structure of the retro-isomer of ferrioxamine E sesqui-hydrate, a ferrioxamine E analog in which the N-hydroxy and carbonyl functions are transposed, was found to be isomorphous with that of ferrioxamine E. The interchange of N and C atoms in the three hydroxamate groups seemed to have caused some noticeable differences in the iron-coordination octahedron. The difference in the average Fe–O(N) and Fe–O(C) distances in the retro-isomer, 0.061, is about one-half of that observed in case of ferrioxamine E, 0.102. The ligand bite of the two complexes is similar (1.27), the retro-isomer has a smaller (42) twist angle than that (45) of ferrioxamine E. Crystal data: C27H45N6O9Fe1.5H2O, triclinic,
P[`1]{P\bar 1}
, a = 19.816(8), b = 10.567(8), c = 7.973(5), = 106.54(6), = 94.99(7), = 97.92(6), V = 1571.1(12)3, Z = 2, D
calc = 1.439g/cm3 = 0.71073.
Journal of Chemical Crystallography 12/1997; 28(1):53-56. · 0.57 Impact Factor
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ABSTRACT: Alternaria longipes ATCC 26293, a highly phytopathogenic fungus, has been found to produce a large number of siderophores under iron-deficient conditions. Most of the compounds are members of the coprogen family. Structures of three novel siderophores, termed hydroxycoprogens, have been determined by1H and13C NMR, FAB mass spectrometry and partial hydrolysis. The compounds are analogs of coprogen, neocoprogen I and isoneocoprogen I, in which one of the terminaltrans-anhydromevalonic acid residues is replaced by atrans-4,5 dihydroxy-3-methyl-2-pentenoic acid residue.
BioMetals 02/1989; 2(1):11-17. · 2.82 Impact Factor
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ABSTRACT: Three novel siderophores have been isolated from a highly pathogenic strain ofAlternaria longipes (ATCC 26293). The compounds are N
-dimethylated analogs of coprogen, neocoprogen I and isoneocoprogen I. Structures of the compounds have been determined by1H- and13C-NMR, fast-atom-bombardment (FAB) mass spectroscopy and partial hydrolysis. One of the new compounds, N
-dimethylcoprogen, is also produced, as the major siderophore, in another fungus,Fusarium dimerum.
BioMetals 02/1988; 1(1):4-8. · 2.82 Impact Factor
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ABSTRACT: Gliocladium virens (ATCC 24290) produces two monohydroxamates (cis- and trans-fusarinine) and a dihydroxamate (dimerum acid) as the major siderophores in the culture filtrate. This fungus also produces minor quantities of three trihydroxamates (the deferri forms of ferricrocin, coprogen B, and coprogen). Structural features of the free ligands and the metal complexed forms of cis-fusarinine (cF), trans-fusarinine (tF), and dimerum acid (DA) have been investigated using electronic (visible), circular dichroism (CD), and NMR spectroscopy. In aqueous solution, in the pH range of 6.5–8.0, all of the ferric complexes of cF (and tF) exist as 3:1 chelates. Fe(cF)3 [or Fe(tF)3] forms both Λ and Δ coordination isomers, but the former in a slight excess. DA forms a 3:2 ferric complex in the pH range of 5.0–8.0. Iron coordination in Fe2(DA)3 is predominantly Δ. DA ligands in Ga2(DA)3 exist as two different conformers at a ratio of 2:1. In mixed solution cF, tF, and DA form a large number of homogeneous and heterogeneous Fe(III) chelates.
Journal of Inorganic Biochemistry.
