A macrocyclic polydentate compound, usually uncharged, in which three or more coordinating ring atoms are or may become suitably close for easy formation of chelate complexes with metal ions or other cationic species.
| Member | Definition | Role |
|---|
| beta-lipotropin, gln(9)- | A crown compound that is enterobactin in which the pro-R hydrogens at positions 2, 6 and 10 of the trilactone backbone are replaced by methyl groups, and in which a glycine spacer separates the trilactone backbone from each of the catecholamide arms. It is the endogenous siderophore of Bacillus subtilis, used for the acquisition of iron. | corynebactin |
| enterobactin | A macrotriolide produced by certain members of Enterobacteriaceae, e.g. Escherichia coli and Salmonella. | enterobactin |
| sodium-binding benzofuran isophthalate | A crown compound that is 1,4,10-trioxa-7,13-diazacyclopentadecane in which the hydrogens of the amino groups at position 7 and 13 are replaced by 2-(2,4-dicarboxyphenyl)-5-methoxy-1-benzofuran-6-yl groups. It is a cell-impermeant fluorescent sodium indicator. | sodium-binding benzofuran isophthalate |