Heliotropin (Piperonal) (CAS 120-57-0) — Sweet Base Note Fragrance Ingredient
Heliotropin (Piperonal)
CAS 120-57-0
What Is Heliotropin (Piperonal)?
Heliotropin, also known as Piperonal, is a sweet, vanilla-like aromatic compound used in perfumes and flavorings. You’ll encounter it in gourmand fragrances, bakery products, and some floral compositions. This ingredient matters because it bridges floral and edible scent worlds, creating comforting yet sophisticated accords. Its stability makes it a perfumer’s favorite for long-lasting sweet notes.
Safety Profile
GENERALLY SAFE
What Does Heliotropin (Piperonal) Smell Like?
Piperonal greets you with an intense, powdery sweetness reminiscent of fresh-baked almond cookies, then unfolds into a creamy vanilla-heliotrope heart. Like a pastry shop at dawn, it balances gourmand warmth with floral delicacy. The dry-down reveals subtle cherry-almond nuances that linger close to skin, creating an intimate sillage. Unlike pure vanilla, it carries a crisp, almost minty edge that prevents cloying sweetness.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Piperonal provides the iconic powdery-anisic backbone of this melancholic masterpiece, blending with iris and carnation to create its twilight haze.
Used sparingly to soften the citrus-vanilla contrast, adding a delicate cherry blossom nuance to the legendary oriental structure.
2D Molecular Structure
SMILES: O=CC1=CC=C2OCOC2=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
Piperonal is a benzodioxole derivative synthesized from safrole or catechol. The methylenedioxy bridge contributes to its stability and distinctive odor profile. Modern production often uses peroxidation of isosafrole, yielding this crystalline solid that sublimes readily. Its planar structure allows excellent diffusion, while the aldehyde group provides reactivity for Schiff base formation in perfumery.
Physical & Chemical Properties
| Boiling Point | 263 °C |
|---|---|
| Melting Point | 37 °C |
| Flash Point | 129 °C |
| Density | 1.337 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-3% | 0.5-5% | Adds powdery sweetness |
| Soaps | 0.5-1% | 0.2-2% | Stable in alkaline media |
| Candles | 2-4% | 1-6% | Good heat resistance |
Classic Accords
+ Mimosa + Iris = Powdery floral
+ Citrus + Musk = Soft oriental
Tip: Use with ionones to create velvety floral effects or with ethyl maltol for candy-like accents.
Alternatives & Comparisons
When a simpler, more straightforward vanilla character is needed without the floral-powdery complexity.
For three times the potency and more caramelized sweetness when projecting power is required.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH, EU Cosmetics Regulation standards update periodically. Consult current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
No restrictions under IFRA 49th Amendment. Listed as safe for use in current categories.
EU Allergen Declaration
Not listed in EU allergen regulation (EC) No 1223/2009.
RIFM Assessment
RIFM-reviewed with no significant safety concerns at reported use levels.
Sustainability
Most piperonal is synthesized from petrochemical precursors, though some is still derived from sustainable sassafras oil in regions where cultivation is permitted. New catalytic processes have reduced environmental impact compared to traditional synthesis routes.
Explore Heliotropin (Piperonal)
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Industry & Science Data
References
- Bickers et al. (2005). Safety assessment of piperonal. Food and Chemical Toxicology. PMID 15979073
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Physicochemical Properties
DTXSID: DTXSID7025924
Physical Properties
| Molecular Weight | 150.133 g/mol🔬 EPA CompTox |
| Density | 1.42 g/cm^3🔬 EPA CTX |
| Boiling Point | 263.356 °C🔬 EPA CTX |
| Melting Point | 36.769 °C🔬 EPA CTX |
| Flash Point | 103.7 °C🔬 EPA CTX |
| Refractive Index | 1.615 Dimensionless📊 OPERA |
| Molar Volume | 112.277 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.05 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 1.23 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.23 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.23 Log10 unitless📊 OPERA |
| Water Solubility | 0.023 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.01 mmHg🔬 EPA CTX |
| Viscosity | 3.175 cP📊 OPERA |
| Surface Tension | 51.1 dyn/cm📊 OPERA |
| Thermal Conductivity | 134.063 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 35.53 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 3 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 39.167 cm^3/mol📊 OPERA |
| Polarizability | 15.527 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
