10 Questions & Answers to Learn More about Cinnamic Acid

Cinnamic acid (CAS NO. 140-10-3) is an important substance because it is widely used in perfume, food, photographic, polymer and pharmaceutical industries, as well as for clinical and toxicological studies. Do you know anything about cinnamic acid? Here is a list of questions & answers which can help you to learn more about cinnamic acid.

What is cinnamic acid?

Cinnamic acid has the formula C6H5CHCHCOOH and is an odorless white crystalline acid, which is slightly soluble in water.

Cinnamic acid is a polyphenol and an antioxidant. It is created by the deamination of phenylalanine and it is then itself converted to any of the various polyphenols synthesized by plants. It is sometimes called the parent polyphenol because all of the myriad polyphenol compounds synthesized by plants are derived from cinnamic acid.

Thus whilst cinnamic acid is itself an antioxidant, its real importance stems from its role in the plant synthesis of the many important polyphenol antioxidant derivatives such as caffeic acid, vanillic acid, ferulic acid, and coumaric acid which are derived from cinnamic acid.

What is IUPAC name of cinnamic acid and what else is it called?

The IUPAC name of cinnamic acid is (E)-3-phenylprop-2-enoic acid. This chemical can be identified by different names, including: trans-Cinnamic acid; trans-3-Phenyl-2-propenoic acid; 3-Phenylpropenoic acid; Cinnamylic acid; 2-Propenoic acid, 3-phenyl-, (2E)-; 3-Phenylacrylic acid; 3-Phenylacrylic acid, etc…

Where does cinnamic acid come from?

Cinnamic Acid is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter.

Is cinnamic acid saturated or unsaturated?

Cinnamic acid is classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.

Is cinnamic acid soluble in water?

Cinnamic acid is slightly soluble in water, and freely soluble in many organic solvents. It is soluble in alcohol, ether, acetic acid, chloroform and acetone, etc…  It is very slightly soluble in water (25 ℃: 0.1; 98 ℃: 0.588), soluble in ethanol (25 ℃: 23), chloroform (15 ℃: 5.9), easily soluble in benzene, ether, acetone, acetic acid and carbon disulfide.

How to dissolve cinnamic acid?

Place 1.0 g of trans-cinnamic acid and 50 mL of 5% NaOH into a 250-mL Erlenmeyer flask. Heat the mixture to 90 oC on a hot plate to dissolve the solid. When the trans- cinnamic acid is dissolved, remove the flask from the hot plate.

What role does cinnamic acid play in cosmetics?

Cinnamic acid has been rated as a low hazard risk for use in skincare and cosmetic formulations and is safe to use as a topical application on the skin.

Is cinnamic acid a phenolic acid?

No, these compounds belong to different chemical classes of compounds.

Phenolic acids are compounds whose molecule contains both a phenolic ring, C₆H₄(OH)-, and a carboxyl group, -COOH.

Cinnamic acid is 3-phenylacrylic acid, C₆H₅-CH=CH-COOH and therefore lacks the phenolic ring characteristic of phenolic acids.

What is the differences between cis and trans cinnamic acid?

Cinnamic acid has trans-/cis- two isomers. The trans-isomer is more stable and has a melting point of 133°C, and a boiling point of 300°C. The cis-isomer forms three polymorphic forms with melting points of 68°, 58°, and 42°C, respectively; the first form, allocinnamic acid, exhibits the highest degree of stability. Cis-cinnamic acid is a naturally occurring compound, presumably converted from trans- cinnamic acid in higher plants.

What is the functions of cinnamic acid derivatives?

Cinnamic acid and its derivatives occur naturally in high levels of plant-based foods. Cinnamic acid derivatives are widely used in cosmetics and possess various functions.