127
A lipophilic coprogen derivative, palmitoylcoprogen (15) is only found inside
the cells and not excreted into the culture broth (Anke et al. 1991).
Bidentate ligand copragens generally capture the Fe
3+
by forming the Fe
3+ 2 Ligand 3
type of structural complexes (Scarrow and Raymond 1985). For example, the three
molecules of rhodotorulic acid makes two ferric ions complex as shown in Fig. 8.8.
Mixed complex of siderophores are also observed with the combination of 3 and
Cis-fusarinine (16) showed in Fig. 8.9 (Jalal et al. 1986).
8.2.2 Ferrichromes
All of these ferrichrome siderophores (Tables 8.2 and 8.3) have a common hexapeptide ring composed of three identical δ-N-acyl-δ-N-hydroxyornithine groups in its
ornithine side chains, but the structure of the acylating acid and their peptide ring
constitution may differ in different ferrichromes. For example, ferrichrysine (17) is
a consecutive cyclic hexapeptide of three amino acids (2 molecules of serine and 1
molecule of glycine) and three molecules of δ-N-acetyl-δ-N-hydroxyornithine
Fig. 8.8 Fe(III) 2 Ligand 3 type of complexes of 2
8 Chemistry and Biomedical Applications of Fungal Siderophores
A lipophilic coprogen derivative, palmitoylcoprogen (15) is only found inside
the cells and not excreted into the culture broth (Anke et al. 1991).
Bidentate ligand copragens generally capture the Fe
3+
by forming the Fe
3+ 2 Ligand 3
type of structural complexes (Scarrow and Raymond 1985). For example, the three
molecules of rhodotorulic acid makes two ferric ions complex as shown in Fig. 8.8.
Mixed complex of siderophores are also observed with the combination of 3 and
Cis-fusarinine (16) showed in Fig. 8.9 (Jalal et al. 1986).
8.2.2 Ferrichromes
All of these ferrichrome siderophores (Tables 8.2 and 8.3) have a common hexapeptide ring composed of three identical δ-N-acyl-δ-N-hydroxyornithine groups in its
ornithine side chains, but the structure of the acylating acid and their peptide ring
constitution may differ in different ferrichromes. For example, ferrichrysine (17) is
a consecutive cyclic hexapeptide of three amino acids (2 molecules of serine and 1
molecule of glycine) and three molecules of δ-N-acetyl-δ-N-hydroxyornithine
Fig. 8.8 Fe(III) 2 Ligand 3 type of complexes of 2
8 Chemistry and Biomedical Applications of Fungal Siderophores