Bacterial constituents part XCI - Anachelin, the siderophore of the cyanobacterium Anabaena cylindrica CCAP 1403/2A

A catecholate siderophore - anachelin - has been isolated from the cyanobac terium Anabaena cylindrica CCAP 1403/2A. The central part of the siderophor e is a tripeptide consisting of L-Thr, D-Ser and L-Ser. Its C-terminus is l inked amidically to a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-7,8-dihydroxy quinolinium system and its N-terminus to 6-amino-3,5,7-trihydroxyheptanoic acid. The 7-hydroxyl group of the latter is esterified with salicylic acid whose carboxyl group is condensed with the 6-amino group to an oxazoline ri ng. Anachelin is the first genuine siderophore of a cyanobacterium whose st ructure has been elucidated.