Progress in Essential Oils: Cubeb Oil

Cubeb oil is obtained by steam distillation of the dried fruit (berries) of Piper cubeba L. (sometimes known as tailed pepper or Java pepper), a member of the Piperaceae family. Piper cubeba is a perennial, woody, dioecious, climbing vine that is mostly grown in Java and Sumatra. The vine possesses slightly aromatic leaves and aromatic globose, berry-like fruit which are borne on a spike similar to black pepper. It is estimated that 5–6 metric tonnes of cubeb oil are produced annually in Indonesia.

A survey of the published reviews on cubeb oil (Lawrence, 1980, 2001, 2009) revealed that the constituents that were unequivocally characterized in this oil, listed in elution order from a non-polar capillary GC column, were as follows:

α -thujene (< 0.1–2.5%)

α -pinene (0.3–7.9%)

sabinene (0.7–29.6%)

β -pinene (< 0.1–0.2%)

myrcene (< 0.1–1.7%)

α -terpinene (< 0.1–1.3%)

p-cymene (< 0.1–1.1%)

limonene (0.1–4.4%)

1,8-cineole (0.3–0.8%)

β -phellandrene (< 0.1–0.8%)

γ -terpinene (0.1–0.7%)

(E)-β -ocimene (< 0.1–0.1%)

cis-sabinene hydrate (< 0.1–0.4%)

terpinolene (< 0.1–0.3%)

linalool (< 0.1–1.0%)

borneol (< 0.1–0.3%)

terpinen-4-ol (0.1–2.7%)

p-cymen-8-ol (0.1–0.3%)

α -terpineol (0.1–2.8%)

cuminaldehyde (< 0.1–0.2%)

δ -elemene (0.1–0.3%)

α -cubebene (1.5–5.7%)

cyclosativene (< 0.1–0.2%)

safrole (< 0.1–0.1%)

α -copaene (3.8–14.3%)

β -cubebene (0.2–11.1%)

β -elemene (1.0–9.4%)

β -caryophyllene (1.1–9.5%)

trans-α -bergamotene (< 0.1–0.2%)

α -humulene (0.5–0.9%)

(E)-β -farnesene (< 0.1–0.2%)

allo-aromadendrene (0.2–11.0%)

γ -muurolene (< 0.1–11.5%)

germacrene D (0.1–11.1%)

epi-cubebol (< 0.1–4.6%)

α -muurolene (0.6–1.7%)

β -bisabolene (1.5–2.0)

γ -cadinene (0.1–0.3%)

cubebol (5.6–30.9%)

cis-calamenene (1.0–3.8%)

δ -cadinene (< 0.1–9.5%)

cadina-1, 4-diene (< 0.1–0.2%)

myristicin (< 0.1–0.1%)

(E)-nerolidol (0.1–3.6%)

ledol (< 0.1–0.2%)

caryophyllene oxide (< 0.1–0.1%)

globulol (< 0.1–3.5%)

dillapiole (< 0.1–0.2%)

1-epi-cubenol (0.3–3.5%)

T-muurolol (< 0.1–0.3%)

α -cadinol (0.2–1.0%)

(E)-asarone (0.9–3.7%)

apiole (< 0.1–0.2%)

An oil produced from the dried fruit of P. cubeba, which was purchased at a local market in Trivandrum (Kerala, India), was produced by hydrodistillation in the laboratory by Sumathykutty et al. (1999). Analysis of this oil by GC-FID and GC/MS revealed that it possessed the following composition:

α -pinene (2.2%)

β -pinene (18.2%)

α -phellandrene (0.2%)

δ -3-carene (0.3%)

p-cymene (0.4%)

limonene (2.0%)

γ -terpinene (0.7%)

linalool oxide^*f (1.4%)

terpinolene (0.2%)

linalool (1.5%)

myrcenol (0.6%)

dihydrolinalool^† (0.1%)

camphor (0.1%)

borneol (0.1%)

terpinen-4-ol (0.1%)

α -terpineol (1.7%)

safrole (0.1%)

thymol (0.1%)

citronellyl acetate (0.5%)

methyl eugenol (2.3%)

α -copaene (0.9%)

β -elemene (7.3%)

β -cubebene (5.6%)

β -caryophyllene (0.4%)

β -copaene (3.3%)

(E)-β -farnesene (0.1%)

α -humulene (0.3%)

allo-aromadendrene (2.3%)

germacrene D (1.5%)

β -bisabolene (3.1%)

δ -cadinene (4.7%)

cubebol (23.6%)

caryophyllene oxide (1.3%)

guaiol (1.0%)

isocedrol (0.2%)

cedrol (0.3%)

β -eudesmol (2.4%)

α -cadinol (0.9%)

β -bisabolol (1.0%)

(Z, Z)- farnesol (0.6%)

(E, Z) - farnesol (0.1%)

^*correct isomer not identified

^f furanoid form

^†does not occur naturally

In addition, trace amounts (< 0.05%) of α -thujene, 1,4-cineole, (E)-β -ocimene, α -fenchyl alcohol, trans-carveol, neral, geraniol, geranial, a sabinyl acetate isomer, α -terpinyl acetate, β -cedrene, cedrene epoxide, (Z, E)- farnesol and (E, E)- farnesol were also characterized in this oil.

Dried P. cubeba berries that were purchased from a local market in Gorakhpur (Uttar Pradesh, India) were ground to 100 mesh and subjected to 4hr hydrodistillation to yield a colorless oil in 2.3% yield. Analysis of the oil using GC-FID and GC/MS by Singh et al. (2007) revealed that the oil possessed the following composition:

α -thujene (4.5%)

α -pinene (4.1%)

sabinene (19.4%)

β -pinene (0.7%)

myrcene (0.3%)

α -phellandrene (0.2%)

p-cymene (1.0%)

β -phellandrene (5.9%)

γ -terpinene (0.2%)

cis-sabinene hydrate (0.9%)

trans-sabinene hydrate (0.5%)

linalool (4.9%)

terpinene-4-ol (0.9%)

δ -elemene (0.3%)

α -cubebene (4.1%)

α -copaene (8.8%)

β -cubebene (18.3%)

β -elemene (0.6%)

α -gurjunene (0.3%)

β -caryophyllene (3.7%)

aromadendrene (0.1%)

α -guaiene (0.2%)

α -humulene (0.9%)

allo-aromadendrene (3.1%)

γ -amorphene (2.0%)

germacrene D (2.6%)

zingiberene (0.1%)

bicyclogermacrene (1.5%)

cubebol^*(0.2%)

α -muurolene (0.6%)

cubebol (4.7%)

γ -cadinene (0.9%)

trans-cadina-1(2), 4-diene (0.2%)

germacrene D (0.1%)

spathulenol (0.4%)

caryophyllene oxide (0.3%)

viridiflorol (0.3%)

^*correct isomer not identified

In addition, trace amounts (< 0.1%) of camphene, δ -3-carene, α -terpinene, 1,8-cineole, terpinolene, camphor and isoledene were also characterized in this oil.

Singh et al. (2008) purchased a second lot of P. cubeba berries from the same local market. These in turn were hydrodistilled after grinding to yield an oil that was subjected to analysis using GC-FID and GC/MS. This oil was found to contain, the following:

α -thujene (1.9%)

α -pinene (1.9%)

sabinene (9.6%)

β -pinene (0.6%)

myrcene (0.2%)

α -phellandrene (0.1%)

p-cymene (0.4%)

limonene (0.5%)

β -phellandrene (1.7%)

1,8-cineole (1.3%)

γ -terpinene (0.1%)

cis-sabinene hydrate (0.7%)

linalool (3.2%)

δ -terpineol (0.6%)

camphor (0.1%)

terpinen-4-ol (1.0%)

α -terpineol (0.3%)

δ -elemene (0.1%)

α -cubebene (3.9%)

α -copaene (7.4%)

geranyl acetate (0.1%)

β -cubebene (18.9%)

β -elemene (1.4%)

α -gurjunene (0.7%)

cis-α -bergamotene (0.3%)

β -caryophyllene (5.3%)

aromadendrene (0.1%)

α -guaiene (0.1%)

α -humulene (2.0%)

allo-aromadendrene (4.1%)

cadina-1(6), 4-diene (0.1%)

γ -muurolene (2.4%)

germacrene D (4.7%)

β -selinene (0.6%)

trans-muurola-4(14),5-diene (0.8%)

bicyclogermacrene (1.5%)

4-epi-cubebol (1.9%)

α -muurolene (0.6%)

germacrene A (0.2%)

cubebol (13.3%)

δ -cadinene (0.2%)

cis-calamenene (0.7%)

germacrene B (0.3%)

(E)-nerolidol (0.7%)

spathulenol (0.5%)

caryophyllene oxide (0.6%)

gleenol (0.1%)

viridiflorol (0.3%)

1-epi-cubenol (0.4%)

isospathulenol (0.1%)

Trace amounts (< 0.1%) of camphene, δ -3-carene, α -terpinene, terpinolene, borneol, cryptone, cuminaldehyde and isoledene were also characterized in this oil. The authors also produced extracts of the same batch of cubeb using diethyl ether, ethanol, petroleum-benzene, chloroform and methanol. The volatiles in amounts of 0.1% or greater characterized in these extracts are listed in T-1.

The percentage volatiles in each of the extracts was 79.6% (diethyl ether), 83.0% (ethanol), 86.6% (petroleum-benzene), 70.1% (chloroform) and 53.4% (methanol).

An oil of P. cubeba that was produced in 1.7% yield by Ismaniar (2013) was analyzed using GC/MS as the method of analysis. The oil was found to contain sativene (8.7%), spathulenol (27.1%), and germacrene D (7.5%) as major constituents.