3.2.1. [Fe]fusarinine C ([Fe]FSC) and [Fe]*N*-Monoacetylfusarinine C ([Fe]MAFC)

The macrocyclic iron protected precursors were obtained according to previously published procedures [19]. Briefly, [Fe]FSC was directly isolated from fungal culture in high yield and sufficient chemical purity (>90%, UV–Vis, λ = 220 nm). The monoacetylated derivative [Fe]MAFC could be isolated with reasonable yield and in high purity (>99% UV-detection, λ = 220 nm) via preparative RP-HPLC from a mixture of mono- and multiple acetylated [Fe]FSC-derivatives when reacting [Fe]FSC with acetic anhydride. Both derivatives gave a red−brown colored solid after lyophilization.

