In Purine nucleosides C - 1 of sugar forms glycosidic linkage with which position of purine ?

Options

A. 1
B. 3
C. 9
D. 8

Answer

To solve the question regarding the glycosidic linkage between the sugar and purine in purine nucleosides, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Purine:**
- Purine is a bicyclic compound composed of a six-membered and a five-membered ring. The key atoms in purine are nitrogen and carbon.

2. **Number the Positions in Purine:**
- The positions in purine are numbered starting from one of the nitrogen atoms in the six-membered ring. The numbering goes as follows:
- 1 (N), 2 (C), 3 (C), 4 (N), 5 (C), 6 (C) for the six-membered ring.
- 7 (N), 8 (C), 9 (N) for the five-membered ring.
- This gives us a total of nine positions in purine.

3. **Understand the Structure of Sugar:**
- The sugar (ribose or deoxyribose) has a carbon backbone. The first carbon (C1) of the sugar is where the glycosidic bond will form with the purine base.

4. **Identify the Glycosidic Linkage:**
- In nucleosides, the glycosidic bond is formed between the C1 position of the sugar and a specific position on the purine base.

5. **Determine the Position of Purine Linked to C1 of Sugar:**
- For purine nucleosides, the C1 of the sugar forms a glycosidic linkage with the 9th position of the purine base.

6. **Conclusion:**
- Therefore, the C1 of the sugar forms a glycosidic linkage with the 9th position of purine.

### Final Answer:
The C1 of the sugar forms a glycosidic linkage with the 9th position of purine.

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