2-Deoxyribose 5-phosphate, acid hydrolysis

Cytosine was isolated from hydrolysis of calf thymus in 1894 and by 1903 its structure was known and it had been synthesized from 2-ethylthiopyrimidin-4(3H)-one. The acid hydrolysis of ribonucleic acid gives nucleotides, among which are two cytidylic acids, 2 -and 3 -phosphates of cytidine further hydrolysis gives cytidine itself, i.e. the 1-/3-D-ribofuranoside of cytosine, and thence cytosine. The deoxyribonucleic acids likewise yield deoxyribonucleotides, including cytosine deoxyribose-5 -phosphate, from which the phosphate may be removed to give cytosine deoxyriboside and thence cytosine. 

Nucleosides and nucleotides are combinations of a base with a sugar. A nucleoside is an N-glycoside formed between a base and a sugar (usually ribose or deoxyribose). A nucleotide is a phosphate ester of a nucleoside. DNA nucleotides are more stable to acid hydrolysis of the glycosidic bond, which is one reason tfrat DNA has superceded RNA as the main genetic storage molecule it is less prone to mutation. 

Deoxy-D-ribose 5-phosphate has been obtained by the action of a nucleoside phosphorylase and a mutase on hypoxanthine , by enzymic condensation of triose phosphate and acetaldehyde and by enzymic phosphorylation of D-2-deoxyribose . Acid hydrolysis of deoxy-adenylic or deoxy-guanylic acid yields deoxyribose 5-phosphate . A chemical s)mthesis is available . 

RNA is relatively resistant to the effects of dilute acid, but gentle treatment of DNA with 1 mM HCl leads to hydrolysis of purine glycosidic bonds and the loss of purine bases from the DNA. The glycosidic bonds between pyrimidine bases and 2 -deoxyribose are not affected, and, in this case, the polynucleotide s sugar-phosphate backbone remains intact. The purine-free polynucleotide product is called apurinic acid. 

The nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are biological polymers that act as chemical carriers of an organism s genetic information. Enzyme-catalyzed hydrolysis of nucleic acids yields nucleotides, the monomer units from which RNA and DNA are constructed. Further enzyme-catalyzed hydrolysis of the nucleotides yields nucleosides plus phosphate. Nucleosides, in turn, consist of a purine or pyrimidine base linked to Cl of an aldopentose sugar—ribose in RNA and 2-deoxyribose in DNA. The nucleotides are joined by phosphate links between the 5 phosphate of one nucleotide and the 3 hydroxyl on the sugar of another nucleotide. 

The fundamental units of nucleic acid, are nucleotides, nucleic acids, and polynucleotides in which the nucleotides are linked by phosphate bridges. Upon extensive heating in the presence of water (hydrolysis), nucleic acids yield amixture of purines and pyrimidines, (i-ribose or (i-deoxyribose, and phosphoric acid. Nucleic acids are subdivided into... 

N. and deoxynucleosides can be synthesized via a Salvage pathway (see). TTiey are also produced by hydrolysis of nucleic acids and nucleotides. Nucleoside phosphorylases and deoxynucleoside phosphorylases catalyse the reversible, phosphate-dependent cleavage of N. and deoxyribonucleosides, forming ribose 1-phosphate or deoxyribose 1-phosphate and the free base. N. and deoxyribonucleosides can be converted into their corresponding nucleotides by the action of specific kinases. 

Complete hydrolysis of nucleic acids (see Section 3.4) by chemical or enzymatic means liberates the nucleic acid building blocks" phosphate, sugar (ribose or deoxyribose), and bases, in a 1 1 1 ratio. Depending on the conditions of the hydrolysis, larger compounds containing these building blocks are obtained (oligonucleotides). 

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