Hydroxamic acids sequestering agents

Recently, Porcheddu and Giacomelli have reported a convenient one-step procednre for the synthesis of hydroxamic acids 215 starting from aldehydes 213 and solid-snpported A-hydroxybenzenesulfonamide 214 (Scheme 92). The hydroxamates are isolated in good to high yields and purities by simple evaporation of the volatile solvents, after treatment of the crude reaction mixture with sequestering agents (216 and 217). 

The second main class of Fem-specific sequestering agents (siderophores) responsible for the acquisition and assimilation of iron employ hydroxamate ligating groups (34).157158 186 Two important subclasses are the ferrioxamines and the ferrichromes (Figure 5). Examples are ferrioxamine B, a linear trihydroxamic acid and ferrichrome A, a cyclic hexapeptide carrying three hydroxamate-containing side chains. 

Polymer-supported reagents and sequestering agents may be used to generate an array of variously substituted amino acid derivatives which were converted to hydroxamic acid derivatives as potential inhibitors of matrix metalloproteinases without any chromatographic purification step [32] (Scheme 5.15). 

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