Capsaicin is an important component of some pain relief ointments - VCE - SSCE Chemistry - Question 7 - 2008 - Paper 1

To determine the functional groups present in capsaicin, we first analyze its molecular structure.

Step 1: Identify Functional Groups

1. Ester Functional Group: An ester is formed from the reaction between an alcohol and a carboxylic acid. In the case of capsaicin, there is no functional group arrangement that resembles an ester.

2. Amide Functional Group: Capsaicin contains a carbonyl group (C=O) bonded to a nitrogen atom, indicating it has an amide functional group. This is identified through the structure as outlined in the provided diagram.

3. Alcohol Functional Group: The presence of an -OH (hydroxyl) group associated with one of the alkyl chains suggests that an alcohol group is present in capsaicin.

4. Alkene Functional Group: An alkene is characterized by a carbon-carbon double bond. While there may be double bonds present in certain chains of capsaicin, the primary structure doesn't depict a straightforward characteristic alkene structure.

5. Carboxylic Acid Functional Group: The structure of capsaicin does not contain the typical -COOH configuration that defines carboxylic acids.

Conclusion

Given the presence of an amide functional group and an alcohol functional group, the correct answer is:

C. an alkene functional group and an amide functional group.