期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：25
页码：14623-14628
DOI：10.1073/pnas.2434016100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Organometallic chemistry offers novel concepts in structural diversity and molecular recognition that can be used in drug design. Here, we consider DNA recognition by {eta}6-arene Ru(II) anticancer complexes by an induced-fit mechanism. The stereochemistry of the dinuclear complex [(({eta}6-biphenyl)RuCl(en))2-(CH2)6]2 + (3, en = ethylenediamine) was elucidated by studies of the half unit [({eta}6-biphenyl)RuCl(Et-en)]+ (2, where Et-en is Et(H)NCH2CH2NH2). The structures of the separated [IMG]f1.gif" ALT="Formula" BORDER="0"> and [IMG]f2.gif" ALT="Formula" BORDER="0"> diastereomers of 2 were determined by x-ray crystallography; their slow interconversion in water (t[1/2] {approx} 2 h, 298 K, pH 6.2) was observed by NMR spectroscopy. For 2 and 3 the [IMG]f1.gif" ALT="Formula" BORDER="0"> configurations are more stable than [IMG]f2.gif" ALT="Formula" BORDER="0"> (73:27). X-ray and NMR studies showed that reactions of 2 and 3 with 9-ethylguanine gave rise selectively to [IMG]f2.gif" ALT="Formula" BORDER="0"> diastereomers. Dynamic chiral recognition of guanine can lead to high diastereoselectivity of DNA binding. The dinuclear complex 3 induced a large unwinding (31{degrees}) of plasmid DNA, twice that of mononuclear 2 (14{degrees}), and effectively inhibited DNA-directed RNA synthesis in vitro. This dinuclear complex gave rise to interstrand cross-links on a 213-bp plasmid fragment with efficiency similar to bifunctional cisplatin, and to 1,3-GG interstrand and 1,2-GG and 1,3-GTG intrastrand cross-links on site-specifically ruthenated 20-mers. Complex 3 blocked intercalation of ethidium considerably more than mononuclear 2. The concept of induced-fit recognition of DNA by organometallic complexes containing dynamic stereogenic centers via dynamic epimerization, intercalation, and cross-linking may be useful in the design of anticancer drugs.
