trans-Cinnamic acid (E-Cinnamic acid) is an organic compound with the formula C?H?CH=CHCOOH. Here's a concise overview of its key aspects:

1. Chemical Structure

• A phenylpropanoid consisting of a benzene ring attached to an acrylic acid group.

• The trans (E) isomer is the stable, naturally occurring form (vs. unstable cis isomer).

• Molecular formula: C?H?O?.

2. Natural Occurrence

• Found in plants (e.g., cinnamon bark, shea resin, balsams) and honey.

• Biosynthesized from phenylalanine via the shikimate pathway.

3. Physical Properties

• White crystalline solid.

• Melting point: 133°C.

• Poor water solubility; soluble in ethanol, ether.

• Strong UV absorption (λ??? ~273 nm).

4. Chemical Significance

• Key intermediate in plant metabolism (precursor to lignins, flavonoids).

• Used in organic synthesis:

• Pharmaceuticals (e.g., precursor to anticoagulant warfarin).

  Perfumes/fragrances (sweet, floral scent).

  Polymers (e.g., styrene-cinnamate copolymers for UV-sensitive films).

5. Biological Activity

• Exhibits antimicrobial, antioxidant, and anti-inflammatory properties.

• Studied for potential roles in cancer prevention and diabetes management.

6. Synthesis

• Industrially produced via Perkin reaction: Benzaldehyde + acetic anhydride (with sodium acetate catalyst).

Applications:

• Cosmetics: UV-filter in sunscreens.

• Food industry: Flavoring agent.

• Agriculture: Plant growth regulator.

Key Fact: Its trans-configuration allows efficient light-driven dimerization (used in photoresist materials).