Chapter 17, Problem 17.42AP

Interpretation Introduction

Interpretation:

Base and monosaccharide in below nucleoside have to be identified. Also, its name has to be assigned.

Concept Introduction:

A nucleoside is a monomer unit that forms the basic structure of the nucleic acid. They are used for medicinal purposes such as anticancer or antiviral agents. They are composed of two units that are as follows:

1. Monosaccharide unit

2. Nitrogen base

Nucleosides are named accordingly as follows:

1. Identify the type of sugar unit attached is ribose or deoxyribose. If in the structure of nucleoside there is an $\text{OH}$ group at $\text{C}{\text{2}}^{\prime }$ then the sugar is ribose sugar and if there is no $\text{OH}$ group at $\text{C}{\text{2}}^{\prime }$ then it is deoxyribose sugar and prefix deoxy is used.

2. Identify the name of the different nitrogen bases present in the molecule. There are two types of bases that are pyrimidine base and purine base.

(a). Pyrimidine base consists of one ring and is present in uracil, cytosine, and thymine.

(b). Purine base consists of two rings and is present in adenine and guanine.

3. Nucleosides with pyrimidine bases end with the suffix $\text{-idine}$ and purine bases end with $\text{-osine}$.

Abbreviation is assigned with respect to the type of sugar. For ribose sugar, 3 letter abbreviation is used and for deoxyribose sugar, 4 letter abbreviation is used followed by d as a prefix.