Chapter 9, Problem 8P

Interpretation Introduction

Interpretation:

The structure of $\text{GlcUAβ(1}\to \text{3)GlcNAc}$ units are connected with $\text{β(1}\to 4)$ should be determined.

Concept introduction:

A Haworth projection is common way to represent the cyclic structure of monosaccharides.

Five and six member hemiacetals are represented as planar pentagons or hexagons.

$\text{α}$ form of the Haworth projection indicates, the exocyclic O group at the anomeric center is on the opposite face as to the ${\text{CH}}_{\text{2}}\text{OH}$ group.

$\text{β}$ form of the Haworth projection, the exocyclic O group at the anomeric center is on the same face as to the ${\text{CH}}_{\text{2}}\text{OH}$ group.

In the Haworth projection ${\text{- CH}}_{\text{2}}\text{OH}$ group is present in the RIGHT side of the ring is called D- form.

In the Haworth projection ${\text{- CH}}_{\text{2}}\text{OH}$ group is present in the LEFT side of the ring is called L- form.

For example:

Haworth projections of glucose:

Pictorial representation:

The structure of Hyaluronic acid where $\text{GlcUAβ(1}\to \text{3)GlcNAc}$ units are connected with $\text{β(1}\to 4)$ is as follows.