Ferulic Acid (1135-24-6) Physical and Chemical Properties
Ferulic Acid
A naturally occurring cinnamic acid derivative and phenolic antioxidant commonly sourced for cosmetic, nutraceutical and pharmaceutical formulation and R&D applications.
| CAS Number | 1135-24-6 |
| Family | Cinnamic acid derivatives |
| Typical Form | Powder or crystalline solid |
| Common Grades | EP, Food Grade, USP |
Ferulic acid is a hydroxy‑methoxy substituted cinnamic acid, classifiable as a hydroxycinnamate (an unsaturated aromatic carboxylic acid). Structurally it is (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoic acid: a para‑hydroxy, meta‑methoxy phenyl ring conjugated to a trans propenoic acid side chain. The conjugated aromatic/vinylic system and the phenolic hydroxyl impart a delocalized π system and a chromophore that absorbs above 290 nm; the carboxylic acid provides a single acidic proton with a modest acidity for an aromatic acid. The molecule can engage in both hydrogen‑bond donation (phenolic OH and carboxylic OH) and multiple hydrogen‑bond acceptor interactions (carbonyl, ether oxygen, phenolic oxygen), promoting intermolecular association and salt formation.
Acid–base behavior is dominated by the carboxyl group: \(\mathrm{p}K_a = 4.58\), so at neutral and physiological pH ferulic acid predominantly exists as the deprotonated anion, increasing aqueous solubility and reducing passive membrane partitioning relative to the neutral form. Log‑partition data indicate moderate lipophilicity (log Kow ≈ 1.51, XLogP ≈ 1.5) and a topological polar surface area (TPSA) of 66.8 Å^2, consistent with an amphipathic profile that affords reasonable solubility in polar organic solvents and limited partitioning into nonpolar phases. The conjugated vinyl–aryl system and the phenolic unit are susceptible to oxidation and photochemical reactions; however, the molecule lacks hydrolyzable ester or labile heteroatom‑linked functionalities that would undergo facile hydrolysis under typical environmental conditions.
Ferulic acid is widely encountered in plant biomass and is used industrially as an antioxidant and preservative; it is also a common feedstock for biocatalytic conversions to value‑added aromatics (for example, conversion to vanillin) and is used in food, cosmetic and analytical applications.
Common commercial grades reported for this substance include: EP, Food Grade, USP.
Basic Physical Properties
Density
No experimentally established value for this property is available in the current data context.
Melting Point
Reported melting range for the predominant trans isomer: 168 - 171 \(\,^\circ\mathrm{C}\). An orthorhombic crystalline form (needles grown from water) has been reported with melting point 174 \(\,^\circ\mathrm{C}\).
Boiling Point
No experimentally established value for this property is available in the current data context.
Vapor Pressure
Reported vapor pressure: \(0.00000269\,\mathrm{mmHg}\).
Flash Point
No experimentally established value for this property is available in the current data context.
Chemical Properties
Solubility and Phase Behavior
The trans isomer is a solid (tan powder) while the cis isomer is reported as a yellow liquid. Solubility behavior (trans form) is solvent‑dependent: soluble in hot water, alcohol and ethyl acetate; moderately soluble in diethyl ether; sparingly soluble in petroleum ether and benzene. The carboxylic acid readily forms salts (e.g., sodium ferulate), which greatly increases aqueous solubility. The compound displays UV absorption maxima in alcohol near 236 and 322 nm (trans form) and ca. 316 nm for the cis form, consistent with the conjugated cinnamate chromophore.
Reactivity and Stability
Ferulic acid is chemically stable under typical ambient conditions but can undergo redox reactions at the phenolic site and conjugated double bond. The phenolic OH is a site for conjugation reactions (e.g., glucuronidation, sulfation in biological systems) and the methoxy group can be demethylated under oxidative or enzymatic conditions. The chromophore (absorption >290 nm) makes the compound susceptible to direct photolysis; vapor‑phase molecules will react with atmospheric hydroxyl radicals on an ~hours timescale. Hydrolysis is not expected to be a significant abiotic degradation pathway because the molecule lacks hydrolyzable functional groups. In the solid state the molecule participates in multiple hydrogen‑bonding motifs, including reported C–H···O interactions in the crystal lattice, which influence crystal packing and stability.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
No experimentally established value for this property is available in the current data context.
Molecular Parameters
Molecular Weight and Formula
Molecular formula: C10H10O4.
Molecular weight: \(194.18\,\mathrm{g}\,\mathrm{mol}^{-1}\).
Exact/monoisotopic mass: 194.05790880.
Additional computed descriptors: heavy atom count 14; formal charge 0; complexity 224; isotope atom count 0.
SMILES: CO C1=C(C=CC(=C1)/C=C/C(=O)O)O
InChI: InChI=1S/C10H10O4/c1-14-9-6-7(2-4-8(9)11)3-5-10(12)13/h2-6,11H,1H3,(H,12,13)/b5-3+
InChIKey: KSEBMYQBYZTDHS-HWKANZROSA-N
(Do not alter SMILES/InChI formatting above; they are provided as structural identifiers.)
LogP and Polarity
Reported log Kow/logP: log Kow = 1.51; XLogP = 1.5. Topological polar surface area (TPSA): 66.8. Hydrogen‑bond donor count = 2; hydrogen‑bond acceptor count = 4; rotatable bond count = 3. These parameters indicate moderate polarity with retained capacity for hydrogen bonding; combined with \(\mathrm{p}K_a = 4.58\), the anionic form at neutral pH increases aqueous affinity and reduces lipophilic membrane partitioning.
Structural Features
Ferulic acid is a (E)-configured cinnamic acid derivative bearing a 4‑hydroxy and 3‑methoxy substitution pattern on the aromatic ring (a guaiacyl motif). The trans (E) configuration across the propenoic double bond is the defined stereochemical state for the common crystalline form. The molecule supports intramolecular resonance between the aromatic ring and the conjugated vinyl‑carboxyl system, stabilizing the carboxylate anion upon deprotonation. Crystal structure data report space group P 1 21/n 1 with unit‑cell parameters: a = 4.58870 \(\text{Å}\), b = 16.7619 \(\text{Å}\), c = 11.7853 \(\text{Å}\); \(\alpha = 90^\circ\), \(\beta = 91.8520^\circ\), \(\gamma = 90^\circ\); Z = 4, Z' = 1; residual factor 0.045. Charge‑density and diffraction analyses indicate multiple intermolecular hydrogen bonding motifs including trifurcated C–H···O interactions that contribute to packing robustness.
Identifiers and Synonyms
Registry Numbers and Codes
CAS: 1135-24-6
Additional registry and database identifiers (as reported): EC numbers 214-490-0; 208-679-7; 805-535-0.
UNII: AVM951ZWST
ChEBI: CHEBI:193350
ChEMBL: CHEMBL32749
DrugBank: DB07767
KEGG: C01494
InChIKey: KSEBMYQBYZTDHS-HWKANZROSA-N
SMILES: COC1=C(C=CC(=C1)/C=C/C(=O)O)O
Synonyms and Structural Names
Common synonyms appearing in supplier and nomenclature lists include: ferulic acid; trans‑ferulic acid; (E)-ferulic acid; 4‑hydroxy‑3‑methoxycinnamic acid; 3‑(4‑hydroxy‑3‑methoxyphenyl)acrylic acid; coniferic acid; (E)-3-(4‑hydroxy‑3‑methoxyphenyl)prop‑2‑enoic acid; trans‑4‑hydroxy‑3‑methoxycinnamate. Multiple depositor and reference synonyms exist reflecting salts, isomers and formulation names.
Industrial and Commercial Applications
Representative Uses and Industry Sectors
Ferulic acid is widely distributed in plant material and is used industrially as an antioxidant and preservative (notably to limit lipid peroxidation in food matrices). It finds application in food and flavoring formulations, cosmetic and personal‑care products as an antioxidant/antimicrobial ingredient, and as an analytical reference standard. In pharmaceutical and traditional medicine contexts, sodium ferulate (the sodium salt) has been used regionally as a cardiovascular/cerebrovascular agent; ferulic acid derivatives are also investigated for antioxidant and radioprotective properties. Additionally, ferulic acid is used as a renewable aromatic feedstock and a precursor in synthetic and biocatalytic routes to higher‑value aromatics (for example, conversion to vanillin) and is a component in some MALDI matrix formulations.
Role in Synthesis or Formulations
Ferulic acid is produced industrially from lignocellulosic sources (e.g., rice bran pitch) or synthetically (for example by Knoevenagel‑type condensations of vanillin derivatives and malonic acid). In chemical and biocatalytic transformations it undergoes reactions typical of hydroxycinnamates: non‑oxidative decarboxylation, O‑demethylation, reduction of the side chain, and enzymatic conjugation. Its capacity to form water‑soluble salts (e.g., sodium ferulate) is exploited in formulations to increase aqueous compatibility. In formulation development its antioxidant capacity and UV‑absorbing chromophore are the principal functional attributes.
Safety and Handling Overview
Acute and Occupational Toxicity
Ferulic acid is associated with skin and eye irritation and may cause respiratory irritation on exposure. Aggregated classification information reports hazard statements including skin irritation (H315), serious eye irritation (H319), and specific target organ (respiratory) irritation (H335); sensitization (skin) has also been reported (H317) in notified classifications. Animal toxicology excerpts include central nervous system effects observed in high‑dose intraperitoneal studies (noted effects at doses with LD50 values reported as > \(350\,\mathrm{mg}\,\mathrm{kg}^{-1}\) via intraperitoneal administration in mice). Routes of occupational exposure of concern are inhalation of dust/aerosol and dermal contact. For emergency treatment of exposure, standard first‑aid measures apply (remove contaminated clothing, flush eyes and skin with water, move to fresh air, seek medical attention); do not induce emesis for ingestion without professional guidance.
For detailed hazard, transport and regulatory information, users should refer to the product‑specific Safety Data Sheet (SDS) and local legislation.
Storage and Handling Considerations
Handle ferulic acid with appropriate industrial hygiene controls: use local exhaust ventilation to control dust and aerosols, and minimize skin and eye contact by using chemical‑resistant gloves and splash goggles or face shields as appropriate. Use respiratory protection when airborne concentrations are likely to exceed occupational exposure limits or in poorly ventilated areas. Store in a cool, dry, well‑ventilated area in tightly closed containers, protected from strong oxidants and from direct sunlight to limit photodegradation; segregate from incompatible materials per standard laboratory/industrial practice. Dispose of waste material in accordance with applicable environmental and regulatory requirements. For detailed hazard, transport and regulatory information, users should refer to the product‑specific Safety Data Sheet (SDS) and local legislation.
