Fluorescence and hybridization properties of peptide nucleic acid containing a substituted phenylpyrrolocytosine designed to engage guanine with an additional H-bond

A new pyrrolocytosine derivative has been designed to selectively interact with guanine and has been evaluated in peptide nucleic acid where it imparts increased selective binding affinity for complementary oligonucleotides. The modified nucleobase also possesses an exceptionally high fluorescence quantum yield that is responsive to hybridization.