Chromatographic research analyte
Sigma documents E-cinnamic acid in a liquid-chromatography/UV and MS/MS compound-library study. [5]
01
THE ESSENTIALS
Cinnamic Acid in 30 Seconds
A CH=CH unit connects the phenyl ring to COOH. E describes the opposite-side arrangement of the higher-priority substituents across that double bond. This structure has no phenolic hydroxyl group.
This page covers E, or trans, cinnamic acid, CAS 140-10-3. Its nonaromatic alkene and aromatic ring are both structural features; the name alone does not establish a quantitative isomer-purity specification. [1] [3]
Safety at a glance — TCI C0353 identifies skin and eye irritation; Sigma 133760 identifies serious eye irritation. Control dust and contact exposure for the solid. Cell-study findings do not justify therapeutic handling or use, and the exact local SDS remains necessary. [4] [5] [6]
Condensed connectivity schematic; see the specified stereochemical identity below. [1]
02
GO A LITTLE DEEPER
Understanding Cinnamic Acid
THE SIMPLE EXPLANATION
The functional groups
A CH=CH unit connects the phenyl ring to COOH. E describes the opposite-side arrangement of the higher-priority substituents across that double bond. This structure has no phenolic hydroxyl group. [1]
A LITTLE DEEPER
What the structure changes
The alkene connects the aromatic ring and carboxyl unit in a conjugated system. Alkene geometry and chemical assay are separate product attributes. Conjugation does not by itself prove a particular antimicrobial or therapeutic effect. [1] [12]
Technical detail Identity, dissociation & specification
The molecular formula specifies the neutral free acid. A commercial solution, salt, ester or anhydride needs its own composition and specification. Quantitative references retain temperature, pressure, product identity and unresolved method qualifiers. [1] [2] [4] [5] [6]
Acid–base reference values describe equilibria under specified conditions. They are not a substitute for a validated formulation or an assay on the purchased lot.
03
MAKE THE CONNECTION
How Cinnamic Acid Compares
Similar names and functional groups do not mean interchangeable chemicals.
SIDE-BY-SIDE COMPARISON
Cinnamic Acid vs Phenylacetic Acid
Aromatic unsaturated monocarboxylic acid
versusAromatic-side-chain monocarboxylic acid
Fixed comparison for this prototype. Acid selectors are disabled; additional comparisons are coming later.
| Property | Cinnamic Acid | Phenylacetic Acid |
|---|---|---|
| Molecular formula | C₉H₈O₂ [1] | C₈H₈O₂ [7] |
| Molecular weight | 148.16 g/mol [1] | 136.15 g/mol [7] |
| Carbon atoms | 9 [1] | 8 [7] |
| Carboxyl groups | 1 [1] | 1 [7] |
| Structure | C₆H₅–CH=CH–COOH · E (trans) [1] | C₆H₅–CH₂–COOH [7] |
| Chemical family | Aromatic unsaturated monocarboxylic acid [1] | Aromatic-side-chain monocarboxylic acid [7] |
| Identity focus | E (trans) free acid [1] | Free acid [7] |
Chemical identities are compared here; supplier grades, concentrations, and stereochemical specifications are separate purchasing attributes. pKa values retain their stated conditions; no quantitative solubility ranking is implied. The structure schematic does not encode stereochemistry.
When Might You Choose One Instead of the Other?
Choose E-cinnamic acid when the method calls for that conjugated aromatic alkene or analytical target. Choose phenylacetic acid for the saturated benzyl acid residue. Request E/Z and other impurity limits separately from a titration or total assay. [1] [3] [7]
Specified starting material
Cinnamic Acid
Match C₆H₅–CH=CH–COOH · E (trans) and the method’s required chemical form.
Phenylacetic Acid
Match C₆H₅–CH₂–COOH; verify the identity before substituting a related acid.
Before choosing: match the reaction or formulation, then verify the exact form, grade, assay basis, and impurities. These contexts do not establish suitability for an industrial or regulated application.
04
FROM STRUCTURE TO APPLICATION
What Is Cinnamic Acid Used For?
Chromatographic research analyte
Sigma documents E-cinnamic acid in a liquid-chromatography/UV and MS/MS compound-library study. This verifies a direct research-analyte context, not certification of the displayed general reagents as reference materials. [5]
06
SOURCE WITH CONTEXT
Cinnamic Acid Suppliers
Compare specific products and package options. Listings are not ranked recommendations.
3 suppliers · 3 products · 8 package listingsLatest supplier check: October 3, 2026
Package sizes stay grouped under the supplier product. Assay methods, product forms, and regional markets remain visible. All three products state trans identity, but their 97%, 98% and 99.5% assays have different stated or unstated methods. A trans name is not a measured isomer-purity percentage. Separate MALDI, food and reference-standard products do not transfer their grades to these listings.
Scroll horizontally if needed. Supplier and package identity stay visible.
| Supplier | Product / Grade | Purity / Assay | Package Size | Public Price | Normalized Price | Documentation | Last Checked | Action |
|---|---|---|---|---|---|---|---|---|
| TCI AmericaCinnamic Acid | Named grade not statedC0353 · 25 gTrans identity. This is not the separate TCI MALDI grade. | GC: minimum 98.0% Neutralization titration: minimum 98.0% | 25 g | $22.00USD · US public price | Not comparedGrades, assay bases, or forms differ | Document notes: TCI America
| View Product: TCI America, C0353 · 25 g (opens new tab) | |
| Named grade not statedC0353 · 100 gTrans identity. This is not the separate TCI MALDI grade. | GC: minimum 98.0% Neutralization titration: minimum 98.0% | 100 g | $31.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: TCI America, C0353 · 100 g (opens new tab) | |||
| Named grade not statedC0353 · 500 gTrans identity. This is not the separate TCI MALDI grade. | GC: minimum 98.0% Neutralization titration: minimum 98.0% | 500 g | $66.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: TCI America, C0353 · 500 g (opens new tab) | |||
| Sigma-Aldrich / MerckCinnamic Acid | Named grade not stated133760-100GTrans identity. 500 g list price shown; promotional USD 134.25 was also displayed. No method or isomer-purity percentage inferred. | 97%; method not stated | 100 g | $38.50USD · US public price | Not comparedGrades, assay bases, or forms differ | Document notes: Sigma-Aldrich / Merck
| View Product: Sigma-Aldrich / Merck, 133760-100G (opens new tab) | |
| Named grade not stated133760-500GTrans identity. 500 g list price shown; promotional USD 134.25 was also displayed. No method or isomer-purity percentage inferred. | 97%; method not stated | 500 g | $179.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: Sigma-Aldrich / Merck, 133760-500G (opens new tab) | |||
| Named grade not stated133760-2KGTrans identity. 500 g list price shown; promotional USD 134.25 was also displayed. No method or isomer-purity percentage inferred. | 97%; method not stated | 2 kg | $443.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: Sigma-Aldrich / Merck, 133760-2KG (opens new tab) | |||
| FUJIFILM WakoCinnamic Acid | Wako Special Grade035-03412Research / further manufacturing. Japan stock does not confirm US availability. Trans identity. 500 g showed out of stock; a catalog price does not establish availability. | 99.5+% (Titration) | 25 g | $45.00USD · US catalog list price | Not comparedGrades, assay bases, or forms differ | Document notes: FUJIFILM Wako
| View Product: FUJIFILM Wako, 035-03412 (opens new tab) | |
| Wako Special Grade039-03415Research / further manufacturing. Japan stock does not confirm US availability. Trans identity. 500 g showed out of stock; a catalog price does not establish availability. | 99.5+% (Titration) | 500 g | $386.00USD · US catalog list price | Not comparedGrades, assay bases, or forms differ | View Product: FUJIFILM Wako, 039-03415 (opens new tab) |
TCI America
Cinnamic Acid
Neutralization titration: minimum 98.0%
Named grade not stated
Trans identity. This is not the separate TCI MALDI grade.
25 g
C0353 · 25 g- Public price
- $22.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
100 g
C0353 · 100 g- Public price
- $31.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
500 g
C0353 · 500 g- Public price
- $66.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: TCI America
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Sigma-Aldrich / Merck
Cinnamic Acid
Named grade not stated
Trans identity. 500 g list price shown; promotional USD 134.25 was also displayed. No method or isomer-purity percentage inferred.
100 g
133760-100G- Public price
- $38.50USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
500 g
133760-500G- Public price
- $179.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
2 kg
133760-2KG- Public price
- $443.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: Sigma-Aldrich / Merck
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
FUJIFILM Wako
Cinnamic Acid
Wako Special Grade
Research / further manufacturing. Japan stock does not confirm US availability. Trans identity. 500 g showed out of stock; a catalog price does not establish availability.
25 g
035-03412- Public price
- $45.00USD · US catalog list price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
500 g
039-03415- Public price
- $386.00USD · US catalog list price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: FUJIFILM Wako
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Documentation evidence
COA = Certificate of Analysis · SDS = Safety Data Sheet · COO = Certificate of Origin.
Lookup means a retrieval option was visible, not that a lot certificate was reviewed. Check supplier means availability or the applicable document was not verified.
Prices may vary by quantity, account, contract, geography, and availability. These products have different grades, assay bases, or forms; no normalized comparison is shown. Foreign-market prices are reference listings only. No currency conversion, mass-to-volume conversion, or ranking is applied. Confirm equivalent specifications and a current quote before comparison. [4] [5] [6]
Verification limits & placement policy
pKa / density: OMITTED. Condition-matched quantitative measurements were not established. Wako’s temperature-free density entry is not promoted. Boiling point: OMITTED. Supplier references around 300 °C lack a verified pressure in the retrieved product data; no atmospheric boiling constant inferred. Melting / geometry: CONDITION-DEPENDENT. Product ranges are for E identity; quantitative E/Z purity remains unverified.
Only the displayed identity, specification, packages, public prices and stated documentation evidence were reviewed. Current stock, lead times, shipping eligibility, contract pricing, lot certificates, and regulatory suitability are unverified.
There are no paid placements. Future paid listings will show “Sponsored” in both views; payment will not determine chemistry interpretation or imply a ranking.
07
PLAN A LARGER ORDER
Need Cinnamic Acid in Bulk?
Turn your requirements into a clear supplier brief.
Bulk RFQ feature — coming soon. Prototype form: submissions are not currently sent to suppliers. Use sample details to prepare an on-screen brief.
Prepare a bulk request Prototype form
08
A BUYER’S CHECKLIST
Before You Buy Cinnamic Acid
Selections remain only while this page is open.
09
FOR YOUR REFERENCE
Cinnamic Acid Technical Reference
Identity, product reference properties, and handling context.
Identification Names, formula & identifiers
- Principal CAS
- 140-10-3
- Identity focus
- E (trans) free acid
- Formula
- C₉H₈O₂
- Molecular weight
- 148.16 g/mol
- IUPAC name
- (E)-3-phenylprop-2-enoic acid
- Connectivity SMILES
- C1=CC=C(C=C1)C=CC(=O)O
- Identity SMILES
- C1=CC=C(C=C1)/C=C/C(=O)O
- InChI
- InChI=1S/C9H8O2/c10-9(11)7-6-8-4-2-1-3-5-8/h1-7H,(H,10,11)/b7-6+
- PubChem CID
- 444539
Connectivity SMILES describes connectivity; it is not an independent stereochemical assignment. CAS and product-form distinctions are supported by the supplier listings. [1] [4] [5] [6]
Physical Properties Product references & conditions
Solid at 20 °C in TCI’s product information; melting ranges are specification/reference values for E material. [13] [4] [5]
- Melting specification
- TCI C0353: 132–136 °C; Sigma literature reference: 132–135 °C [4]
- Water-solubility context
- TCI describes poor water solubility; qualitative wording is not a zero-solubility measurement [4]
Hydrate, concentration, stereoisomer, and temperature can change the relevant specification. Product reference data are not a reviewed lot certificate.
Acid/Base Properties Verified values & missing data
A numeric pKa was not verified for the selected identity in this review; no value is inferred. [2]
pKa / density: OMITTED. Condition-matched quantitative measurements were not established. Wako’s temperature-free density entry is not promoted. Boiling point: OMITTED. Supplier references around 300 °C lack a verified pressure in the retrieved product data; no atmospheric boiling constant inferred. Melting / geometry: CONDITION-DEPENDENT. Product ranges are for E identity; quantitative E/Z purity remains unverified.
Temperature, ionic strength, and the use of activities versus concentrations matter in quantitative work. These reference values are not buffer recipes.
Safety at a Glance Product-specific hazards
TCI C0353 identifies skin and eye irritation; Sigma 133760 identifies serious eye irritation. Control dust and contact exposure for the solid. Cell-study findings do not justify therapeutic handling or use, and the exact local SDS remains necessary. [4] [5] [6]
Hazard classifications can vary by concentration, product, supplier and jurisdiction. Review the SDS for the exact product before handling. This summary does not replace the SDS.
Supplier safety information and SDS retrieval (opens new tab)
A product-page safety classification is not verification of every regional SDS. Confirm product code, chemical form and current local document.
Review supplier documentation10
COMMON QUESTIONS
Cinnamic Acid FAQ
What distinguishes Cinnamic Acid?
A CH=CH unit connects the phenyl ring to COOH. E describes the opposite-side arrangement of the higher-priority substituents across that double bond. This structure has no phenolic hydroxyl group. [1]
How does it differ from Phenylacetic Acid?
Phenylacetic acid has a saturated one-carbon side chain; cinnamic acid has a two-carbon alkene side chain. That changes carbon count, conjugation and geometric identity. Neither acid is interchangeable in a method specifying the other. [7]
What must a buyer specify?
All three products state trans identity, but their 97%, 98% and 99.5% assays have different stated or unstated methods. A trans name is not a measured isomer-purity percentage. Separate MALDI, food and reference-standard products do not transfer their grades to these listings. [4]
Are the listed products directly price-comparable?
No. The table retains differing grades, assay bases, forms, and markets. No normalized ranking or currency conversion is applied. [5]
What reference data still need checking?
pKa / density: OMITTED. Condition-matched quantitative measurements were not established. Wako’s temperature-free density entry is not promoted. Boiling point: OMITTED. Supplier references around 300 °C lack a verified pressure in the retrieved product data; no atmospheric boiling constant inferred. Melting / geometry: CONDITION-DEPENDENT. Product ranges are for E identity; quantitative E/Z purity remains unverified.
Can I request a bulk quote here?
The RFQ is a prototype that prepares an on-screen brief. Nothing is sent to suppliers. Confirm actual bulk terms directly with the supplier.
11
TRACE THE INFORMATION
Sources & Editorial Notes
Identity and compiled reference values are separated from supplier-specific specifications. Structural comparisons and buyer guidance are editorial interpretation. Sources were checked October 3, 2026; supplier information can change.
- PubChem · chemical identity (opens new tab)
Neutral molecular identity verified independently through PUG REST; CAS also checked on all selected supplier products.
- PubChem / HSDB · dissociation references (opens new tab)
No numeric field promoted: insufficient conditions or unresolved conflicting records.
- PubChem / HSDB · application references (opens new tab)
Attributed application records reviewed claim by claim. Free acid, intermediate, derivative and biological context are distinguished.
- TCI America · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- Sigma-Aldrich / Merck · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- FUJIFILM Wako · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- Phenylacetic Acid · identity (opens new tab)
Primary structural comparison. Practical interpretation does not establish suitability.
- Benzoic Acid · identity (opens new tab)
Related identity and structural relationship.
- Crotonic Acid · identity (opens new tab)
Related identity and structural relationship.
- Sorbic Acid · identity (opens new tab)
Related identity and structural relationship.
- Phenylacetic Acid · dissociation references (opens new tab)
Only independently reviewed values are promoted into the comparison; no condition-free acidity ranking.
- OpenStax · Carboxylic-acid structure and properties (opens new tab)
General carboxylate resonance, acidity and structural interpretation; not authority for this acid’s quantitative constants.
- PubChem / HSDB · attributed physical references (opens new tab)
Attributed references reviewed; product, phase, pH and method gaps stated rather than inferred.
Review limits
pKa / density: OMITTED. Condition-matched quantitative measurements were not established. Wako’s temperature-free density entry is not promoted. Boiling point: OMITTED. Supplier references around 300 °C lack a verified pressure in the retrieved product data; no atmospheric boiling constant inferred. Melting / geometry: CONDITION-DEPENDENT. Product ranges are for E identity; quantitative E/Z purity remains unverified.
This informational prototype is not a supplier, quotation service, or endorsement of a product’s fitness for an application. Buyers should verify the applicable specification, certification, and regulatory requirements for their intended use.