Pungent principle, a sinigrin, of crucifers is a

Options

A. (a) glycoside having sulphur
B. (b) glycoside having cyanide
C. (c) having special amino acids
D. (d) tannin

Answer

**Step-by-Step Solution:**

1. **Identify the Compound:** The question refers to "sinigrin," which is a pungent principle found in cruciferous plants.

2. **Understand the Family:** Sinigrin is associated with the family Brassicaceae, commonly known as crucifers. This family includes vegetables like cabbage, broccoli, brussels sprouts, and mustard seeds.

3. **Chemical Structure:** Sinigrin is identified as a glycoside that contains sulfur. Glycosides are compounds where a sugar is bound to another functional group via a glycosidic bond.

4. **Enzymatic Reaction:** When cruciferous vegetables are crushed, an enzyme called myrosinase is activated. This enzyme catalyzes the conversion of sinigrin into its aglycone form and subsequently into allyl isothiocyanate.

5. **Properties of Allyl Isothiocyanate:** Allyl isothiocyanate is a volatile compound responsible for the pungent smell and taste of mustard oil and other cruciferous vegetables. It is also noted for its medicinal properties, including anti-inflammatory and antioxidant effects.

6. **Evaluate the Options:**
- Option A states that sinigrin is a glycoside having sulfur, which aligns with the information provided.
- Option B mentions glycoside having cyanide, which is incorrect.
- Option C refers to special amino acids, which is also incorrect.
- Option D states tannin, which is not relevant to sinigrin.

7. **Conclusion:** Based on the analysis, the correct answer is Option A: glycoside having sulfur.

---