Peptides are compounds of amino acids joined by amide bonds. Which of the following statements is correct ?

Options

A. Amide groups are more resistant to hydrolysis than are similar ester groups
B. p - p resonance stabilizes the amide bond
C. Stable conformations of peptide are restricted to those having planar amide groups
D. Amide groups do not participate in hydrogen bonding interactions

Explanation

To determine which statement about peptides and amide bonds is correct, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Peptides and Amide Bonds**:
- Peptides are formed by the linkage of amino acids through amide bonds (also known as peptide bonds). An amide bond is formed between the carboxyl group of one amino acid and the amino group of another.

2. **Analyzing Option A**:
- **Statement**: "Amide group more resistant to hydrolysis than the similar ester group."
- **Evaluation**: This statement is incorrect. Amide bonds are generally less resistant to hydrolysis compared to ester bonds. Therefore, this option is false.

3. **Analyzing Option B**:
- **Statement**: "π-π resonance stabilizes amide group."
- **Evaluation**: This statement is misleading. While amide groups do exhibit resonance, it is primarily due to the delocalization of the lone pair on nitrogen with the carbonyl group, which is not accurately described as π-π resonance. Hence, this option is also false.

4. **Analyzing Option C**:
- **Statement**: "Stable conformers of peptides are restricted to those planar amides."
- **Evaluation**: This statement is correct. Amide bonds are planar due to the partial double bond character, which restricts rotation around the bond. Thus, this option is true.

5. **Analyzing Option D**:
- **Statement**: "Amide group do not participate in hydrogen bond."
- **Evaluation**: This statement is incorrect. Amide groups can participate in hydrogen bonding due to the presence of both a nitrogen and an oxygen atom, which can act as hydrogen bond donors and acceptors. Therefore, this option is false.

### Conclusion:
The correct statement among the options provided is **Option C**: "Stable conformers of peptides are restricted to those planar amides."