Proton-NMR study of the interaction of trans-dichloro-diamine-platinum(II) with poly(I) and poly(I)·poly(C)

✍ Scribed by G. Victor Fazakerley; Dominique Hermann; Wilhelm Guschlbauer; Geoffrey E. Hawkes

• Publisher: Wiley (John Wiley & Sons)
• Year: 1984
• Tongue: English
• Weight: 577 KB
• Volume: 23
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360230511

✦ Synopsis

The fixation of trans-(NH&Clz Pt(I1) to poly(1)-poly(C) a t low rb (<0.05) leads to the formation of two complexed species. The major species (ca. 82% of bound platinum) involves coordination of platinum to a single hypoxanthine base, while the other species involves coordination of two hypoxanthine bases, which are either far apart on the same strand or on separate poly(1) strands, to the platinum. These same two species are found after reaction with poly(I), as are two other species throughout the entire rb range studied (rb = 0-0.30). The latter two species are assigned to trans-Pt bound to two bases on a poly(1) strand with (a) one or (b) two free bases between the two bound bases. These two species, (a) and (b), account for ca. 35% of the bound platinum, although the 1:l species remains dominant (ca. 55%). These two additional species are observed a t high (>0.075) after reaction with poly(I)-poly(C) but as very minor species. They are formed by reaction with melted poly(1) loops. Also at high rb, we have observed a shifted cytidine H5 resonance arising from interaction of trans-Pt with a melted loop of poly(C). Most probably, this arises from an intramolecular poly(1) to poly(C) crosslink. Results from the reaction of trans-Pt with poly(C) are presented for comparison.