P-D-ribose

Nitrogenous base plus sugar moiety are called nucleosides. Ribonucleic acids (RNA) resemble DNA in that nucleoside monophosphates are joined through phosphodiester bonds. RNAs differ in that the sugars are p-D-ribose units and the pyrimidine uracil is found in place of thymine. Molecular structures and nomenclature for nitrogenous bases, nucleosides, and nucleotides are delineated in Table 2.2. 

RNA is made up of nucleotides similar to DNA, except that the sugar is P-d-ribose compared to DNA s P-D-deoxyribose (Fig. 2.4).There are two-stranded RNAs, but normally RNA exists in single strand form. 

Figure 33 The two forms of sugar residues commonly found in nucleic acids. P-D-Ribose is the sugar constituent of RNA, while p-D-2-deoxyribose is a component of DNA.

Ribitol is the reduction product of D-Ribose. P-D-Ribose-1 -phosphate is the phosphoric ester of the OH group on the anomeric carbon of P-D-ribofuranose. 

FAB CID at low collision energy of the (M — H) anion from the decaprenylphosphates of P-D-ribose... 

Figure 11.8. Envelope Conformations of P - d -ribose. The C2-endo and C3-endo forms of p -d-ribose are shown. The color indicates the four atoms that lie approximately in a plane. 

A sugar, P D-ribose (in RNA) or P D-2 -deoxyribose (in DNA). This sugar is in the cyclic five-membered furanoside form. 

Refer to the linear structure of D-ribose. Draw the Haworth projections of a- and P-D-ribose. Note that D-ribose is a pentose. 

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