CADINENE

Cadinene is a natural sesquiterpene hydrocarbon found in essential oils of various plants, particularly in patchouli, cade oil, and cubeb oil. 
It exists in multiple isomeric forms, the most common being α-cadinene and γ-cadinene, and it plays a role in the aroma and biological activity of essential oils.

CAS Number: 483-76-1
Synonyms:
Cadinenes,Cadinane hydrocarbons,Sesquiterpene hydrocarbons from cade oil
Terpenoid compounds from essential oils

Introduction
Sesquiterpenes represent a diverse and abundant class of naturally occurring terpenoid compounds composed of three isoprene units, with the molecular formula C₁₅H₂₄. Among them, cadinene is a noteworthy sesquiterpene hydrocarbon, widely distributed in many aromatic plants and essential oils. 
It contributes to the characteristic woody, spicy aroma of oils extracted from species such as patchouli (Pogostemon cablin), juniper (Juniperus spp.), and cade oil derived from Juniperus oxycedrus.

The interest in cadinene extends beyond its olfactory properties, as it exhibits notable biological activities including antimicrobial, insecticidal, and antioxidant effects. 
Due to these properties, cadinene finds applications in perfumery, traditional medicine, and potentially as a bioactive agent in pharmaceutical and agricultural sectors.

The study of cadinene encompasses its chemical identity, natural occurrence, extraction, physical and chemical properties, biosynthesis, biological activity, and industrial applications. 
This article aims to provide a comprehensive overview of cadinene, highlighting its importance in various scientific and commercial contexts.

Chemical Identity
Cadinene is a sesquiterpene hydrocarbon with the molecular formula C₁₅H₂₄ and a molecular weight of 204.35 g/mol. 
The compound exists in several isomeric forms, primarily α-cadinene, γ-cadinene, and δ-cadinene, which differ in the positions of their double bonds and stereochemistry.

Isomeric Forms
α-Cadinene
α-Cadinene is the most commonly found isomer in nature. 
It features a double bond positioned at C4-C5 in the cadinane skeleton, influencing its chemical reactivity and aroma. 
This isomer is responsible for much of the characteristic woody and spicy scent in essential oils like patchouli and cade oil.

γ-Cadinene
γ-Cadinene differs in the placement of the double bonds, which changes its three-dimensional shape and odor profile. 
It is also found in various plant sources but typically at lower concentrations than α-cadinene.

δ-Cadinene
δ-Cadinene is less common and sometimes conflated with γ-cadinene due to structural similarities. 
It shows subtle differences in both biological activity and olfactory properties.

These isomers' subtle structural differences affect their physical properties, reactivity, and interaction with biological targets, influencing their industrial and pharmacological relevance.

Natural Occurrence
Cadinene is widely distributed in essential oils from various plant species, contributing to their unique fragrance and biological effects.

Notable sources include:
Patchouli (Pogostemon cablin): A tropical plant whose essential oil is rich in α-cadinene, lending a warm, woody aroma used extensively in perfumery.
Cade Oil (Juniperus oxycedrus): Contains cadinene isomers, providing a smoky, woody scent.
Cubeb Oil (Piper cubeba): Contains cadinene, contributing to its spicy fragrance.
Cypress (Cupressus sempervirens), Cedarwood (Cedrus spp.), and Juniperus species: Essential oils often have measurable cadinene content.
The concentration of cadinene in these oils can vary depending on factors such as geographic location, climate, plant maturity, and extraction method.

Extraction and Isolation
The isolation of cadinene from natural sources involves several steps:
Steam Distillation: The primary method for extracting essential oils containing cadinene. 
Plant material is subjected to steam to vaporize volatile compounds, which are then condensed.

Solvent Extraction: Non-volatile fractions containing cadinene can be extracted using organic solvents like hexane or ethanol.

Chromatographic Separation: Techniques such as Gas Chromatography (GC) and High-Performance Liquid Chromatography (HPLC) are used to separate cadinene isomers for analysis and purification. Preparative chromatography can isolate individual isomers for further study.

Spectroscopic Characterization
Cadinene and its isomers can be characterized using several spectroscopic techniques that provide insights into their molecular structures:

Infrared (IR) Spectroscopy: Cadinene exhibits characteristic absorption bands corresponding to C–H stretching (~3000 cm⁻¹), C=C double bonds (~1640 cm⁻¹), and methyl group bending vibrations (~1375 cm⁻¹). 
Differences in the position of double bonds between isomers cause slight shifts in absorption peaks.

Nuclear Magnetic Resonance (NMR) Spectroscopy:
¹H NMR: Shows signals for methyl, methylene, and olefinic protons. For α-cadinene, olefinic protons resonate downfield (δ ~5.1–5.5 ppm).
¹³C NMR: Distinguishes carbon environments, identifying sp² carbons at double bonds and sp³ carbons in the hydrocarbon framework. 
The chemical shifts differ between isomers, aiding differentiation.

Mass Spectrometry (MS): Electron ionization mass spectra show molecular ion peaks at m/z = 204, with fragmentation patterns characteristic of sesquiterpenes, including losses of methyl and isopropyl groups.

UV-Visible Spectroscopy: Due to lack of conjugation, cadinene has minimal UV absorbance, but double bonds may absorb weakly near 200–220 nm.
Combined, these techniques enable structural elucidation and purity assessment of cadinene samples.

Physical and Chemical Properties
Physical State: Colorless to pale yellow liquid at room temperature.
Boiling Point: Approximately 260–280 °C (varies by isomer and purity).
Melting Point: Generally low; specific data depend on isomer and impurities.
Density: Around 0.85 g/cm³.
Refractive Index: Approximately 1.48–1.50.
Solubility: Insoluble in water; soluble in organic solvents such as ethanol, ether, and chloroform.

Chemical Reactivity:
Contains one or more double bonds, making it susceptible to electrophilic additions, oxidation, and polymerization under harsh conditions.
Generally chemically stable under ambient conditions but can oxidize when exposed to air and light over prolonged periods.

Biosynthesis in Plants
Cadinene biosynthesis occurs via the mevalonate pathway (MVA pathway) in plant cells:
The pathway starts with acetyl-CoA, leading to the formation of isopentenyl diphosphate (IPP), the basic five-carbon building block of terpenoids.
Three IPP units condense to form farnesyl diphosphate (FPP), the direct precursor for sesquiterpenes.
Cadinene synthase enzymes catalyze the cyclization of FPP into the cadinane skeleton.
Stereochemical outcomes and double bond positions depend on specific enzymes expressed in the plant.

SAFETY INFORMATION ABOUT CADINENE

 
First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product