Pyrrolidino-DNA.

We synthesized pyrrolidino-C-nucleosides, incorporated them into oligodeoxynucleotides and investigated their pairing properties. The thermal duplex and triplex stabilities were measured. While triplex formation is destabilized in the case of pyrrolidino-pseudo-U and -T, pyrrolidino-pseudo-iso-C leads to an increase of the Tm value for third strand dissociation. Duplexes are destabilized with all pyrrolidino-C-nucleosides.