SYNTHESIS OF 4-GUANIDINOPYRIMIDINE NUCLEOSIDES FOR TRIPLE HELIX-MEDIATED GUANINE AND CYTOSINE RECOGNITION

Recognition of DNA sequences by triple helix-forming oligonucleotides is restricted to homopurine sequences. Based on geometrical considerat ions, a single nucleoside, 4-guanidinocytidine 1, was designed to reco gnize both guanosine (as the natural 1 beta anomer) and cytidine (as t he 1 alpha anomer) in a new triple helix context where the third stran d is centered in the major groove of the target duplex. Several method s of synthesis of this nucleoside are described. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.