Question

Tannins chemically belongs to which class?

• A. Alkaloids
• B. Phenolic compounds
• C. Steroids
• D. Glycosides

Hint:

Tannins are the astringent (mouth-puckering) compounds found in tea, unripe fruits and many barks. To classify them, look at the chemical groups present in their structure.

Answer 1

The Correct Option is B

Concept:
Tannins are the astringent (mouth-puckering) compounds found in tea, unripe fruits and many barks. To classify them, look at the chemical groups present in their structure.

Step 1:
Tannins are large molecules rich in many hydroxyl (–OH) groups attached to benzene rings. Anything built around phenol (an –OH on a benzene ring) belongs to the phenolic compounds class.

Step 2:
It is these abundant phenolic –OH groups that let tannins bind and precipitate proteins, which explains their astringent action and their use in tanning leather.

Step 3:
They are not nitrogen-based like alkaloids, not ring-fused like steroids, and although some are linked to sugars, their defining chemistry is phenolic, not glycosidic.

Answer: Option (2) — Phenolic compounds.