1-p-Menthene-8-thiol (CAS 71159-90-5) — Citrus Top Note Fragrance Ingredient
1-p-Menthene-8-thiol
CAS 71159-90-5
What Is 1-p-Menthene-8-thiol?
1-p-Menthene-8-thiol is a synthetic fragrance compound that creates tropical fruit aromas, particularly reminiscent of grapefruit and passionfruit. It’s found in high-end perfumes and some specialty food flavorings. This ultra-potent molecule is prized for its ability to add exotic fruity top notes at extremely low concentrations, making it a secret weapon for perfumers crafting tropical or citrus-forward fragrances.
Safety Profile
PROFESSIONAL USEWhat Does 1-p-Menthene-8-thiol Smell Like?
At concentrations above 1 ppb, this thiol explodes with an intense, almost aggressive grapefruit peel character – think of crushing fresh pink grapefruit zest between your fingers. The initial burst evolves into a complex tropical fruit basket with aspects of passionfruit, guava, and a hint of catty muskiness. The dry-down reveals a surprisingly clean, slightly woody base. One of the most potent aroma chemicals known, detectable at parts per trillion levels.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used at trace levels to enhance the sparkling citrus top notes, adding dimension to the bergamot accord with a tropical fruit undertone.
Contributes to the vibrant citrus opening, blending with lemon and apple notes to create its signature refreshing quality.
2D Molecular Structure
SMILES: CC1=CCC(CC1)C(C)(C)S
Chemistry, Properties & Perfumer Guide
The Chemistry
1-p-Menthene-8-thiol is a monoterpenoid thiol featuring a p-menthane skeleton with a sulfur-containing functional group at the 8-position. Synthesized through selective thiolation of p-menthane precursors, often via hydrothiolation of limonene derivatives. The thiol group is responsible for both its extreme potency and characteristic grapefruit aroma. Chirality plays a significant role in odor perception, with different enantiomers exhibiting varying intensity and character.
Physical & Chemical Properties
| Detection Threshold | 0.0001 ppb in water |
|---|---|
| Odor Type | Fruity, tropical, citrus |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.001-0.01% | Up to 0.05% | Used at ppm levels for effect |
| Functional Fragrance | 0.0001-0.001% | Up to 0.005% | Extreme caution required |
| Flavor | ppb levels | Up to 1 ppm | GRAS but highly restricted |
Classic Accords
Tip: Always pre-dilute to 0.1% or lower before incorporating into blends – direct use can overwhelm entire formulations.
Alternatives & Comparisons
Less potent grapefruit thiol alternative with similar character but easier handling for less experienced perfumers.
Provides tropical fruit notes without the extreme potency challenges, though lacks the grapefruit specificity.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No specific IFRA restrictions, but recommended usage levels are extremely low due to potency (typically <0.01%).
GHS Classification
RIFM Assessment
RIFM evaluation confirms safe use at extremely low concentrations typical in fragrance applications.
Sustainability
As a synthetic material, production is controlled in laboratory settings without significant environmental impact. The extreme potency means minuscule quantities are required, resulting in negligible resource consumption per unit of fragrance produced. No known issues with biodegradation at usage levels.
Explore 1-p-Menthene-8-thiol
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Breme K. et al. (2010). Structure-Odor Relationships of Mercapto-p-Menthanes. Chemistry & Biodiversity. DOI:10.1002/cbdv.201000008
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 71159-90-5Physical Properties
| Molecular Weight | 170.32 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.8🔬 PubChem |
| Boiling Point | 37 °C🔬 EPA CompTox |
| Vapor Pressure | 0.4571 mmHg @ 25°C📊 OPERA |
| Involatility Index | 0.0377💻 Calculated |
| log Kp (skin permeability) | -1.751💻 Calculated |
| SMILES | CC1=CCC(CC1)C(C)(C)S🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 0.6 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | grapefruit• leffingwell |
| Functional Groups | thiolalkene💻 RDKit |
| 1-p-Menthene-8-thiol has an aroma and taste of grapefruit in dilute solution.📖 Fenaroli | |
Sensory Thresholds
| Odor Detection Threshold | 0 ppm📖 van Gemert |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID1052458
Physical Properties
| Molecular Weight | 170.31 g/mol🔬 EPA CompTox |
| Density | 0.948 g/cm^3🔬 EPA CTX |
| Boiling Point | 226.191 °C📊 OPERA |
| Melting Point | -7.3 °C📊 OPERA |
| Flash Point | 80.899 °C📊 OPERA |
| Refractive Index | 1.501 Dimensionless📊 OPERA |
| Molar Volume | 181.519 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.903 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.903 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.828 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.97 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.37 mmHg📊 OPERA |
| Viscosity | 2.529 cP📊 OPERA |
| Surface Tension | 29.465 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 0 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 53.437 cm^3/mol📊 OPERA |
| Polarizability | 21.184 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.
