Aromatherapy Essential Oil Chemistry 2 — Questions and Answers
Question 1: Which chemical family is primarily responsible for the fresh, citrusy aroma in oils like lemon and orange?
- Monoterpenes (Correct answer)
- Sesquiterpenes
- Phenols
- Oxides
Correct answer: Monoterpenes
Monoterpenes such as limonene dominate citrus oils and give them their fresh, light aroma.
Question 2: The compound eugenol, known for its numbing and antiseptic action, belongs to which chemical group?
- Phenols (Correct answer)
- Esters
- Ketones
- Aldehydes
Correct answer: Phenols
Eugenol is a phenol found in clove oil, giving it strong antiseptic and warming properties.
Question 3: Which functional group is most associated with the calming, relaxing esters found in lavender oil?
- Linalyl acetate (Correct answer)
- Menthol
- Camphor
- 1,8-cineole
Correct answer: Linalyl acetate
Linalyl acetate is an ester that contributes to lavender's soothing, sedative character.
Question 4: Oxides such as 1,8-cineole are best known for which therapeutic effect?
- Expectorant and respiratory support (Correct answer)
- Wound sedation
- Digestive bitters
- Photosensitizing
Correct answer: Expectorant and respiratory support
1,8-cineole (eucalyptol) is a respiratory expectorant common in eucalyptus and rosemary.
Question 5: Which class of oxygenated compounds can be neurotoxic in high doses, requiring caution with oils like pennyroyal?
- Ketones (Correct answer)
- Monoterpenes
- Esters
- Alcohols
Correct answer: Ketones
Ketones such as pulegone can be neurotoxic and hepatotoxic if overused.
Question 6: Sesquiterpenes, such as chamazulene in German chamomile, are chiefly noted for what property?
- Anti-inflammatory action (Correct answer)
- Photosensitivity
- Sedative overdose risk
- Rapid oxidation to acids
Correct answer: Anti-inflammatory action
Sesquiterpenes like chamazulene are recognized for their anti-inflammatory and soothing effects.
Question 7: Which structural feature distinguishes sesquiterpenes from monoterpenes?
- Fifteen carbons vs. ten carbons (Correct answer)
- Presence of nitrogen
- A benzene ring core
- Water solubility
Correct answer: Fifteen carbons vs. ten carbons
Monoterpenes have ten carbons (two isoprene units) while sesquiterpenes have fifteen (three isoprene units).
Aromatherapy Essential Oil Chemistry 2
Which chemical family is primarily responsible for the fresh, citrusy aroma in oils like lemon and orange?