X-ray structure of the zinc complex of the central metal chelation site ofthe antitumour drug streptonigrin

The X-ray structure of the 1:1 complex between zinc(II) triflate and 3-amin o-6,6'-bis(methoxycarbonyl) -2,2'-bipyridine is reported. This ligand conta ins the central chelation site present in the DNA-binding antitumour antibi otic streptonigrin. The complex is distorted octahedral involving the 2,2'- bipyridyl site and the carbonyl groups at the 6,6'-positions as well as two axial water molecules. The structure confirms that formation of similar co mplexes with streptonigrin is possible. (C) 2000 Elsevier Science Ltd All r ights reserved.