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Show IIIo In the INTRODUCTION TO THE NUCLEOSIDE.PROBL,EM lst few years the become ceIlt:ral pr-ob.Lem in' molecul,ar' .func't Lon of nucleic acids has biology The double-helix 0 deoxyribonucleic acid (DNA) as to secondary structure of ribonucleic acid now and their drivativeso bering systemo of either In particular little work has given (the nucleotides) The structures of the nucleosides just nucleotides minus are However, aqueous,solutions and that of DNA in the monomeric units of the nucleic acids on RNA and DNA ben well establishedo (RNA) in amorphou solids and in solutions there been done are has remain much to be studiedo to seem . configuratiqn of the crystalline salts of the invstigtiQn of thf! pq:pef(tie and in a molecule of Figure phosphoric acid) 301 along with the All nucleosides may be considered purine or pyrimi4n (see Figure 30l},0 (which found in convent,io,nal. numas derivatives The purine or pyrimidine chromophores are soetimes referre, o a "the nitrogen base" or imply "the base chromopbere o· Note that there chromophores: to the plane to the are two types of nitrogen (1) Pyridine type rngl'l a lone-pair orbital (2) Pyrrole type nitrogen which ,adds conjugate sY$temo ! . in the base nitrgn which furnish one electron delocalized =system and have of the atoms in the two electrons |
