“…Microorganisms have themselves developed siderophore–antibiotic conjugates known as sideromycins (Braun and Braun, ; Braun et al ., ; Mislin and Schalk, ), in which the antibiotic moiety is connected to the siderophore via a spacer arm. The archetypal conjugates of this type are albomycins (Benz et al ., ; Braun and Braun, ; Mislin and Schalk, ), ferrimycins (Bickel et al ., ), danomycins (Tsukiura et al ., ), salmycins (Tsukiura et al ., ) and certain microcins (de Lorenzo, ; de Lorenzo et al ., ; Thomas et al ., ; Destoumieux‐Garzon et al ., ; Nolan and Walsh, ). These natural siderophore–antibiotic conjugates can chelate iron(III) and are then transported into the target bacterium via the siderophore‐dependent iron uptake pathways.…”