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Cosmetic antioxidants

Caffeic acid

Also known as 3,4-Dihydroxycinnamic acid, 3,4-Dihydroxybenzeneacrylic acid, 3-(3,4-Dihydroxyphenyl)-2-propenoic acid

CAS 331-39-5Formula C9H8O4Molar mass 180.16 g/molEC 206-361-2
GHS signal word: Warning. Pictograms: Harmful or irritant, Serious health hazard 123 suppliers listed Drug substance
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Caffeic acid chemical structure, C9H8O4, CAS 331-39-5
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Yellow crystals from concentrated aqueous solutions. Alkaline solns turn from yellow to…
Melting point
223 to 225
Solubility
Sparingly soluble in cold water. Freely soluble in hot water, cold alcohol.
HS code
291829
Category
Cosmetic antioxidants
Illustrative photo, yellow pigment powder in an open kraft paper sack in a chemical plant
Typical packagingIllustrative packaging image, not the actual product

What is Caffeic acid?

Plain description, key identifiers and synonyms

Caffeic acid is a hydroxycinnamic acid that is cinnamic acid in which the phenyl ring is substituted by hydroxy groups at positions 3 and 4. It exists in cis and trans forms, the latter is the more common. It has a role as an antioxidant, an EC 3.5.1.98 (histone deacetylase) inhibitor, an EC 1.13.11.34 (arachidonate 5-lipoxygenase) inhibitor, an EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor, an EC 2.5.1.18 (glutathione transferase) inhibitor and a plant metabolite. It is a hydroxycinnamic acid and a member of catechols.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
(E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid
CAS number
331-39-5 CAS number cross-checkedOther or deprecated CAS: 331-89-5, 501-16-6, 71693-97-5
EC numbers
206-361-2, 689-473-8
Molecular formula
C9H8O4
UNII
U2S3A33KVM
MDL number
MFCD00004392
INCI name
CAFFEIC ACID
InChIKey
QAIPRVGONGVQAS-DUXPYHPUSA-N
InChI
InChI=1S/C9H8O4/c10-7-3-1-6(5-8(7)11)2-4-9(12)13/h1-5,10-11H,(H,12,13)/b4-2+
Canonical SMILES
O=C(O)C=Cc1ccc(O)c(O)c1
Isomeric SMILES
C1=CC(=C(C=C1/C=C/C(=O)O)O)O

Synonyms

  • 3,4-Dihydroxycinnamic acid
  • 3,4-Dihydroxybenzeneacrylic acid
  • 3-(3,4-Dihydroxyphenyl)-2-propenoic acid
  • Cinnamic acid, 3,4-dihydroxy-
  • (E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid
  • 2-Propenoic acid, 3-(3,4-dihydroxyphenyl)-
  • 4-(2-Carboxyethenyl)-1,2-dihydroxybenzene
  • 3-(3,4-Dihydroxyphenyl)propenoic acid
  • 4-(2'-Carboxyvinyl)-1,2-dihydroxybenzene
  • trans-3,4-Dihydroxycinnamic Acid
  • 2-Propenoic acid, 3-(3,4-dihydroxyphenyl)-, (2E)-
  • Caffeic Acid 1507
  • caffeic acid, (E)-
  • Trans 3,4-Dihydroxycinnamic acid
  • (2Z)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid
  • cis-Caffeic acid
  • trans-caffeic acid
  • 3-(3,4-dihydroxyphenyl)acrylic acid
  • (E)-3-(3,4-dihydroxyphenyl)acrylic acid
  • (2E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid
  • 3,4-Dihydroxy-trans-cinnamate
  • Caffeate
  • 2-Propenoic acid, 3-(3,4-dihydroxyphenyl)-, (E)-
  • 3-(3,4-Dihydroxy phenyl)-2-propenoic acid
  • Caffeicacid
Show all 36 synonyms
  • (E)-3,4-dihydroxycinnamic acid
  • 3,4-Dihydroxycinnamic acid, predominantly trans
  • caffeic-acid
  • e-caffeic acid
  • Caffeic acid pure
  • (e)-caffeic acid
  • Caffeic acid, 1
  • Caffeic acid, trans-
  • 3,4-dihydroxycinnamate
  • CAFFEIC ACID natural
  • (2E)-3-(3,4-dihydroxyphenyl)acrylic acid

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
Yellow crystals from concentrated aqueous solutions. Alkaline solns turn from yellow to orangeexp.
Melting point
223 to 225exp.
Solubility
Sparingly soluble in cold water. Freely soluble in hot water, cold alcohol.exp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
180.16 g/molcalc.
Exact mass
180.0423 Dacalc.
LogP (octanol/water)
1.2calc.
Topological polar surface area
77.76 Ųcalc.
Hydrogen bond donors
3calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
2calc.
Heavy atoms
13calc.
Rings
1calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccccc1

c1ccccc1

1 ring, 6 atoms, the Benzene ring system.

485,677 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
  • H351Suspected of causing cancer.
  • H361Suspected of damaging fertility or the unborn child.
Precautionary statements (18)
  • P203Obtain, read and follow all safety instructions before use.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P318If exposed or concerned, get medical advice.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Caffeic acid suppliers

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All 123 suppliers
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Where suppliers are based

123 suppliers in 17 countries

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Caffeic acid price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Caffeic acid is not know to be a significant commercial product. It is available as the trans isomer in research quantities at purities ranging from 97% to greater than 99%, the cis isomer of caffeic acid is not available commercially.

Cosmetic ingredient, INCI name CAFFEIC ACID(antioxidant, fragrance)

Pharmacological actions

  • Antioxidants

Roles

  • animal metabolite
  • antioxidant
  • enzyme inhibitor
  • eukaryotic metabolite
  • geroprotector
  • lipoxygenase inhibitor
  • mammalian metabolite
  • metabolite
  • mouse metabolite
  • pharmaceutical
  • plant metabolite
  • protective agent

Functional uses

  • Antioxidant
  • Deodorizer

Cosmetic functions

  • Antioxidant
  • Fragrance

Pharmacology

Caffeic Acid is an orally bioavailable, hydroxycinnamic acid derivative and polyphenol, with potential anti-oxidant, anti-inflammatory, and antineoplastic activities. Upon administration, caffeic acid acts as an antioxidant and prevents oxidative stress, thereby preventing DNA damage induced by free radicals. Caffeic acid targets and inhibits the histone demethylase (HDM) oncoprotein gene amplified in squamous cell carcinoma 1 (GASC1, JMJD2C, KDM4C) and inhibits cancer cell proliferation. GASC1, a member of the KDM4 subgroup of Jumonji (Jmj) domain-containing proteins, demethylates trimethylated lysine 9 and lysine 36 on histone H3 (H3K9 and H3K36), and plays a key role in tumor cell development.

How it is made

Constituent of plants, probably occurs in plants only in conjugated forms, e.g., chlorogenic acid.

Isolation from green coffee: Wolfrom et al., J. Agr. Food Chem. 8, 58 (1960), from roasted coffee: Krasemann, Arch. Pharm. 293, 721 (1960). Formation by acid hydrolysis of chlorogenic acid: Fiedler, Arzneimittel-Forsch. 4, 41 (1954), Whiting, Carr, Nature 180, 1479 (1957), Guern, C.A. 61, 9965h (1964).

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory
  • Active ingredient in FDA approved drug labels

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Caffeic acid is traded under.

HS 2918.29Indicative HS code

Carboxylic acids, (with phenol function but without other oxygen function), their anhydrides, halides…

World exports in 2024
$861M
+0.9% vs 2023, imports $892M
2019 to 2024
Top exporters
  1. China30.5%
  2. South Korea18.3%
  3. Switzerland * partner reported13.3%
Top importers
  1. United States14.7%
  2. Germany13.3%
  3. Japan10.3%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Caffeic acid is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Caffeic acid, based on the data on this page

What is Caffeic acid?

Caffeic acid is a hydroxycinnamic acid that is cinnamic acid in which the phenyl ring is substituted by hydroxy groups at positions 3 and 4. It exists in cis and trans forms, the latter is the more common.

What is the CAS number of Caffeic acid?

The CAS registry number of Caffeic acid is 331-39-5. Other or deprecated CAS numbers: 331-89-5, 501-16-6, 71693-97-5.

What is the molecular formula and weight of Caffeic acid?

The molecular formula of Caffeic acid is C9H8O4 and its molar mass is 180.16 g/mol.

What is Caffeic acid used for?

Caffeic acid is not know to be a significant commercial product. It is available as the trans isomer in research quantities at purities ranging from 97% to greater than 99%, the cis isomer of caffeic acid is not available commercially.

Is Caffeic acid hazardous?

Caffeic acid carries the GHS signal word "Warning". Main hazards: causes skin irritation, causes serious eye irritation, may cause respiratory irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Caffeic acid?

Caffeic acid is usually classified under HS code 291829 (Carboxylic acids with phenol function but without other oxygen function, their…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Caffeic acid?

CompoundList lists 123 suppliers of Caffeic acid in China, United States, Germany, United Kingdom and 13 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Caffeic acid?

Suppliers quote Caffeic acid on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Caffeic acid

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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