Correct option is A
Explanation-
β-thioglucosidases, also known as myrosinases, are enzymes that specifically hydrolyze glucosinolates — a group of natural compounds found predominantly in Brassicaceae family plants (e.g., mustard, broccoli, cabbage). When plant tissue is damaged (e.g., by herbivores), myrosinases come into contact with glucosinolates, leading to their hydrolysis. This reaction produces biologically active compounds like isothiocyanates, thiocyanates, and nitriles, which serve as defense chemicals against pests and pathogens.
Incorrect Options -
Option b - Terpenoids – Derived from isoprene units; not hydrolyzed by β-thioglucosidases.
Option c - Alkaloids – Nitrogen-containing compounds, not glucoside-based, and not substrates for myrosinase.
Option d - Phenolics – Contain phenol groups; not specifically acted upon by myrosinases.
Final Answer: Option a – Glucosinolates
