Alizarine dye obtained from the root of madder plant is Anthra quinone derivative. Its structure corresponds to -

Options

A. 1, 2- dihydroxy anthraquinone
B. 2, 3- dihydroxy anthraquinone
C. 1, 4- dihydroxy anthraquinone.
D. 1 - hydroxyl anthraquinone.

Answer

To determine the structure of Alizarin dye, which is an anthraquinone derivative obtained from the root of the madder plant, we can follow these steps:

### Step 1: Understand the Structure of Anthraquinone
Anthraquinone is a compound that consists of three fused benzene rings with two carbonyl (C=O) groups. It has the general formula C14H8O2.

### Step 2: Identify the Hydroxy Groups
Alizarin is specifically known as 1,2-dihydroxyanthraquinone. This means that there are two hydroxyl (–OH) groups attached to the anthraquinone structure.

### Step 3: Determine the Positions of Hydroxy Groups
In the name 1,2-dihydroxyanthraquinone:
- The "1" indicates that there is a hydroxyl group at the first carbon of the anthraquinone structure.
- The "2" indicates that there is another hydroxyl group at the second carbon.

### Step 4: Draw the Structure
To draw the structure:
- Start with the anthraquinone backbone (three fused rings).
- Add the two hydroxyl groups at the 1st and 2nd positions.

### Step 5: Compare with Given Options
The options provided are:
1. 1,2-dihydroxyanthraquinone
2. 2,3-dihydroxyanthraquinone
3. 1,4-dihydroxyanthraquinone
4. 1-hydroxyanthraquinone

Since we have identified the structure as 1,2-dihydroxyanthraquinone, the correct answer is option 1.

### Final Answer
The structure corresponds to **1,2-dihydroxyanthraquinone** (Option A).

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