Aureolic acid oligosaccharides

Iodo-glycosides can be a valuable alternative to the above-mentioned 2-bromo derivatives. Easily prepared via addition reactions to glycals of NIS or I(coIl)2C104 and alcohols [30,157], these donors were successfully used in the synthesis of aureolic acid oligosaccharides [155,156,158]. 

Members of this group feature tricyclic carbon framework decorated with two oligosaccharide chains. Mithramycin 48 and chromomycin A3 49 are two aureolic acids that have found their use in cancer chemotherapy. These compounds, interacting with Mg2+, bind GC-rich DNA in a nonintercalative way, and sugar chains are indispensable in stabilizing metal-antibiotic complexes. Carbohydrates are... 

Aureolic acids are a group of tetrahydroanthracene oligosaccharide antibiotics, the name of which is related to their characteristic golden appearance. Members of the aureolic acid group include chromomycin A3, olivomycin A and mithramycin, as the most prominent examples (O Fig. 15). 

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