Intercalating nucleic acids: The inversion of the stereocenter in 1-O-(pyren-1-ylmethyl)glycerol from R to S. Thermal stability towards ssDNA, ssRNA and its own type of oligodeoxynucleotides

The synthesis and insertions of (S)-1-O-(pyren-1-ylmethyl)glycerol into intercalating nucleic acids is described. Insertions of this S-isomer as a bulge lead to reduced binding affinity towards complementary ssDNA compared to intercalating nucleic acids possessing (R)-1-O-(pyren-1-ylmethyl)glycerol in the same positions. Insertions of both (R) or (S) 1-O-(pyren-1-ylmethyl)glycerols as bulges into two complementary strands decreased the stability of the complex compared to dsDNA possessing the pyrene pseudo-nucleotide in one of the strands.