The absolute stereochemistry of anachelins, siderophores from the cyanobacterium Anabaena cylindrica

The absolute stereochemistry of anachelins ( and ), siderophores isolated from the freshwater cyanobacterium Anabaena cylindrica, was determined via the application of Boc-phenylglycine and Mosherʹs method. Consequently, it was revealed that a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-6,7-dihydroxyquinolinium unit (Dmaq) has 3S (eq.) configuration, and a 6-amino-3,5,7-trihydroxyheptanoic acid unit (Atha) has 3R, 5S, 6S configuration. The 6S configuration of Atha suggested that l-Ser was a biosynthetic precursor of Atha.