Synthesis of some modified nucleosides

Abstract

The synthesized C-Ompmmds include amino and amino acids residues

,also some of the synthesized derivatives had a biological activity since it had the ability to interfere into the ONA of the cell .Such that modified nucleosides arc derivatives from the nonnal nucleosides which had an important role in biological acti,ity especially the binding between tRNA and mRNA . They had an important role in protein biosynrhesis. SOme of these twcleosides used as aotibiotics and can be prepared in laboratory which are resemble in the structure of the nucleosides which are present in DNA . Also it can be used as amiturnor , attifungs , inhibitor for

virus and used as therapy for both of rhewnatic arthritis and increa.sing uric

acid in blood .

g-Bromoguanoeine was used as a suitable substrate and it was easily prep• ared by reacting guanosine with bromine in presence of water.Then it was used as a substrate to prepare rnany derivatives by tmc!eophil!ic substitution