Question

The 'royal jelly' on which queen larvae are fed contains

• A. 10-hydroxy-trans-2-decanoic acid
• B. 10-hydroxy-cis-2-decanoic acid
• C. 10-hydroxy-cis-4-decanoic acid
• D. 10-hydroxy-trans-4-decanoic acid

Hint:

The chemical marker of royal jelly is 10-HDA, which possesses a trans double bond at position 2 of the 10-carbon chain.
Always look for "trans" and "2" in the option text.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Royal jelly is a nutrient-rich glandular secretion produced by nurse worker honey bees, which plays a major role in caste determination and queen development.

Step 2: Detailed Explanation:
Royal jelly is fed to all honey bee larvae for the first three days of life, but only the larva designated to become the queen is fed royal jelly exclusively throughout her entire larval stage.
Chemically, royal jelly is a complex mixture of proteins, sugars, lipids, vitamins, and free fatty acids.
The major lipid component and primary bioactive marker of royal jelly is a unique 10-carbon intermediate chain fatty acid.
This specific bio-compound is scientifically identified as 10-hydroxy-2-decenoic acid (commonly referred to as 10-HDA, or under decanoic acid nomenclature).
Its natural, biologically active form is the trans-isomer: 10-hydroxy-trans-2-decenoic acid (or 10-hydroxy-trans-2-decanoic acid derivatives).
This compound possesses potent antibacterial, immunomodulatory, and caste-inducing properties, ensuring the development of healthy, long-lived queen bees.

Step 3: Final Answer:
Royal jelly contains the key bioactive compound 10-hydroxy-trans-2-decanoic acid.