Anthraquinones as artificial DNA building blocks

Synthesis and properties of oligodeoxynucleotides containing anthraquinone-derived building blocks with flexible linkers are described. Starting from the 1,4-, 1,5-, 1,8- and 2,6-dihydroxyanthraquinone isomers, the corresponding phosphoramidites were prepared and incorporated into oligonucleotides. The site of linker attachment was found to be of critical importance for hybrid stability. Whereas the 2,6-isomer led to a significant stabilization, all other isomers had a negative effect on the stability of the duplex. Spectroscopic studies showed that the anthraquinones behave as fluorescence quenchers. Models of anthraquinone-modified double-stranded hybrids are proposed. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).