Eugenol vs Iso-Eugenol — Two Allylphenol Isomers, Two Markets
Eugenol and iso-eugenol are structural isomers — same chemical formula (C10H12O2) but different placement of the propenyl group. The chemistry shift completely changes the aroma profile, the F&F role, and the upstream synthesis routes.
Eugenol
- Spicy, warm, clove character
- Allyl side chain (CH2-CH=CH2)
- FEMA 2467; widely allergen-listed in EU
- Primary use: dental antiseptic (pharma), F&F spice bases, flavour
- Ex-clove leaf or ex-clove bud
- Mid-tier pricing
Iso-Eugenol
- Sweet, creamy, slightly floral / carnation
- Propenyl side chain (CH=CH-CH3)
- FEMA 2468; vanillin precursor
- Primary use: F&F floral bases, vanillin synthesis feedstock
- Synthetic-route from eugenol isomerisation
- Mid-tier pricing
Spec comparison
| Parameter | Eugenol | Iso-Eugenol |
|---|---|---|
| IUPAC | 4-Allyl-2-methoxyphenol | 2-Methoxy-4-propenyl-phenol |
| CAS | 97-53-0 | 97-54-1 |
| FEMA | 2467 | 2468 |
| Side chain | Allyl (CH2-CH=CH2) | Propenyl (CH=CH-CH3) |
| Aroma | Warm spice, clove, peppery | Sweet, creamy, carnation, vanilla-precursor |
| Specific gravity | 1.066–1.070 | 1.077–1.083 |
| Refractive index | 1.5400–1.5440 | 1.5720–1.5760 |
| Primary industry | Dental pharma, F&F spice, flavour | F&F floral, vanillin precursor |
| Pricing band | Mid-tier | Mid-tier |
When to choose what
Eugenol for
Dental antiseptic (eugenol-zinc oxide pastes), clove-spice F&F compounds, spice flavour bases, pharma topical, traditional medicine.
Iso-Eugenol for
F&F floral-carnation bases, vanillin synthesis (industrial route to natural-identical vanillin), classical Oriental fragrance bases.
Don’t substitute
Same formula, totally different aroma. The structural difference is unmistakable on GC-MS — different retention times.
Allergen note
Both are on the EU allergen-23 list. Cosmetic products require allergen declaration above the 0.001% (leave-on) / 0.01% (rinse-off) threshold.
What ships for both from our plant
Same upstream eugenol-isomerisation chemistry; both ship with same QC architecture:
- GC-MS chromatogram per lot (eugenol or iso-eugenol % reported)
- NABL retain-sample testing
- FEMA + FCC food-grade documentation
- REACH + IFRA conformance + Allergen-23 declaration (mandatory)
- 1 kg sample → 25 kg drum → 180 kg → FCL ladder
- Sample programme: paid, credit-back against bulk order in 60 days
- Pharma-grade eugenol available with monograph reference
Buyer FAQ
Why is iso-eugenol the vanillin precursor?
Iso-eugenol can be oxidised at the propenyl side chain to give vanillin (4-Hydroxy-3-methoxybenzaldehyde). The eugenol-to-iso-eugenol isomerisation followed by oxidation is one of the major industrial routes to “natural-identical vanillin.”
Eugenol allergen restriction in cosmetics?
Yes — both eugenol and iso-eugenol are EU allergen-23 listed. Allergen declaration mandatory on cosmetics above the threshold. IFRA also restricts the % presence in finished fragrance.
Dental-grade eugenol — purity?
Pharmacopoeia-grade eugenol for dental use: ≥98–99% assay, pharmacopoeia-compliant COA, specific impurity profile (no methyl eugenol contamination — separately regulated).
Can I get methyl eugenol?
Yes — separately produced and supplied. Methyl eugenol is regulated under IFRA 50th amendment due to safety concerns; specific applications only.
Minimum order?
1 kg sample → 25 kg HDPE drum → 180 kg → FCL on either SKU.
Eugenol or Iso-Eugenol bulk quote in 4 hours
One RFQ — quote(s) back the same working day. 1 kg sample plan with full credit-back.