Sapphyrin and its conjugates

One critical exception is the sapphyrin-ethylenediaminetetraacetic (EDTA) conjugate (23). Previous studies of small molecule-EDTA conjugates have shown that these species, in the presence of iron(II), Oj, and a suitable reducing agent, can effect the cleavage of the DNA backbone. In turn, so-called affinity cleavage can be used to elucidate the specificity of the small molecule-DNA interactions. It was thus considered worth making 23. ... 

A rare and interesting example of ONSH with the methoxy group in the sapphyrin dioxouranium (VI) complex has been described (Scheme 34) [130, 131]. Sapphyrin (22-pentaphyrin[l,l,l,l,0]) has 22 electrons in the frames of its Jt-conjugated system, and it belongs to the expanded porphyrin family, thus allowing one to consider it as a macrocyclic aromatic compound. 

Subsequent to the preparation of 8, a number of other sapphyrin-nucleobase conjugated carriers were synthesized in the authors laboratories. These include compound 9 that has two cytosine moieties appended to the sapphyrin macrocycle, as well as two guanine-bearing sapphyrins, 10 and 11. Here, as expected, the ditopic sapphyrin-guanine receptor 10 served to enhance the transport of cytosine-5 -monophosphate (but not GMP or AMP). By contrast, the two tritopic receptors, namely 9 and 11, were designed with the intention of allowing for the formation of the complexation-derived triple-helix-like C-G-C and G-C-G motifs in addition to phosphate chelation by sapphyrin. In other words, it was expected that a centrally... 

The sapphyrin-lasalocid conjugate 5.125 was reported recently. It was synthesized under amide-forming conditions similar to those used to prepare the sapphyrin nucleobase conjugates 5.111, 5.113, 5.117, and 5.119. Specifically, the sapphyrin acid 5.109 was activated using l-(3-dimethylaminopropy)-3-ethylcarbodii-... 

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