Carbohydrate calicheamicin/esperamicin

J.3 Synthetic Approaches to the Calicheamicin/Esperamicin Carbohydrate Fragments... 

Simulation of the calicheamicin/esperamicin cascade has been amply demonstrated by Danishefsky and co-workers with a variety of compounds (Scheme 7-49) [219-221]. Furthermore, comparisons of ealicheamicin yj (2) and calicheamicinone (222) in DNA-cleavage experiments pointed to the importance of the carbohydrate fragment of the natural product in the molecular recognition of its target sequence [85]. 

NMR studies depicting natural products bound to DNA, conducted by the Patel laboratory, provided a detailed understanding as to how the carbohydrate motifs engaged double-stranded DNA and delivered selectivity.30 Structures of the DNA complexes of esperamicin At (Figure 3.2a)31 and calicheamicin X (Figure 3.2b)32 identified multiple interactions between the carbohydrate motifs and the DNA backbone. 

Synthetic work has been reported on compound 9 which is a hydrolytically stable analogue of GM3 ganglioside lactone. Compound 10, which contains a trisaccharide having a hydrojgrlamine linking unit, and which is a derivative of the carbohydrate domain of calicheamicin, has been reported, and carbohydrate fragments of esperamicin Aj which also contain this type of bonding, have likewise been described. ... 

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