LIMONENE

CAS NO: 5989-27-5
EC Numarası: 227-813-5

synonyms:
(+)-(R)-4-isopropenyl-1-methylcyclohexene;(+)-limonene;(-)-limonene;(4R)-1-methyl-4-(1-methylethenyl)cyclohexene;(4S)-1-methyl-4-isopropenylcyclohex-1-ene;(D)-limonene;(R)-(+)-limonene;(R)-4-isopropenyl-1-methylcyclohexene;1-methyl-4-(1-methylethenyl)cyclohexene;4-mentha-1,8-diene;AISA 5203-L (+)limonene;cyclohexene, 1-methyl-4-(1-methylethenyl)-, (4R)-;d-limonene;dipentene;limonene;limonene, (+)-;limonene, (+-)-isomer;limonene, (R)-isomer;limonene, (S)-isomer;D-Limonene;(+)-Limonene;5989-27-5;(R)-(+)-Limonene;(+)-(4R)-Limonene;(+)-carvene;Citrene;(+)-p-Mentha-1,8-diene;(4R)-Limonene;(+)-Dipentene;Carvene;Glidesafe;Glidsafe;Kautschiin;Refchole;(+)-R-Limonene;D-(+)-Limonene;(R)-p-Mentha-1,8-diene;D-Limonen;(R)-4-Isopropenyl-1-methyl-1-cyclohexene;d-p-Mentha-1,8-diene;(D)-Limonene;(R)-Limonene;Limonene, D-;Biogenic SE 374;(+)-alpha-Limonene;d-Limonene (natural);d-Limoneno [Spanish];(+)-(R)-Limonene;(+)-4-Isopropenyl-1-methylcyclohexene;Hemo-sol;(4R)-(+)-Limonene;(R)-(+)-p-Mentha-1,8-diene;UNII-GFD7C86Q1W;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (4R)-;(R)-1-Methyl-4-(1-methylethenyl)cyclohexene;CCRIS 671;FEMA No. 2633;EC 7;(4R)-4-isopropenyl-1-methylcyclohexene;HSDB 4186;D-1,8-p-Menthadiene;NCI-C55572;EINECS 227-813-5;p-Mentha-1,8-diene, (R)-(+)-;Limonene, (+)-;(+)-1,8-para-Menthadiene;AI3-15191;CHEBI:15382;1-Methyl-4-(1-methylethenyl)cyclohexene, (R)-;(R)-1-Methyl-4-(prop-1-en-2-yl)cyclohex-1-ene;r-(+)-limonene;(4R)-1-methyl-4-(prop-1-en-2-yl)cyclohex-1-ene;MFCD00062991;SBB055254;(4R)-1-methyl-4-prop-1-en-2-ylcyclohexene;(4R)-1-methyl-4-(1-methylethenyl)cyclohexene;(+)-Limonene, stabilized with 0.03% tocopherol;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (theta)-;d-Limoneno;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (R)-;D-limonene [JAN];Citrus stripper oil;Terpenes and Terpenoids, limonene fraction;Sulfate turpentine, distilled;Dextro-limonene;d limonene;citre ne;Racemic limonene;65996-98-7;EINECS 266-034-5;(+) Limonene;limonene, (R)-isomer;D-Limonene Reagent Grade;DSSTox_CID_778;AC1L9A6P;DSSTox_RID_75785;GFD7C86Q1W;DSSTox_GSID_20778;4betaH-p-mentha-1,8-diene;CHEMBL449062;DTXSID1020778;HMDB04321;(R)-(+)-Limonene, 95%;(R)-(+)-Limonene, 97%;MolPort-002-507-206;XMGQYMWWDOXHJM-JTQLQIEISA-N;ZINC967513;CS-M3273;(R)-(+)-Limonene, >=93%;Tox21_200400;6458AE;ZINC00967513;AKOS015899935;LMPR0102090013;LS-1427;NE11118;(R)-(+)-Limonene, analytical standard;NCGC00248591-01;NCGC00257954-01;(4R)-4-isopropenyl-1-methyl-cyclohexene;AJ-24525;AK117763;DR000133;OR115854;SC-65387;ZB015452;CAS-5989-27-5;(4R)-1-methyl-4-isopropenylcyclohex-1-ene;(R)-(+)-4-Isopropenyl-1-methylcyclohexene;FT-0603053;L0047;L0105;C06099;(4R)-1-methyl-4-(1-methylvinyl)cyclohex-1-ene;J-502148;W-105295,I14-11275;(R)-(+)-Limonene, primary pharmaceutical reference standard;CYCLOHEXENE; 1-METHYL-4-(1-METHYLETHENYL)-; (R)-;UNII-9MC3I34447 component XMGQYMWWDOXHJM-JTQLQIEISA-N;(R)-(+)-Limonene, purum, >=96.0% (sum of enantiomers, GC);(R)-(+)-Limonene, technical, ~90% (sum of enantiomers, GC);1051930-86-9;7705-13-7;94765-75-0;95327-98-3;R-limonene;orange peel oil;citrus peel oil;citrene;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (R)-; p-Mentha-1,8-diene, (R)-(+)-; (+)-(R)-Limonene; (+)-(4R)-Limonene; (+)-p-Mentha-1,8-diene; (+)-Limonene; (R)-(+)-Limonene; Carvene; D-(+)-Limonene; Limonene, (D)-; Limonene, (+)-; (R)-1-methyl-4-(1-methylethenyl)cyclohexene; Dextro-limonene; (R)-4-Isopropenyl-1-methyl-1-cyclohexene; 4-Isopropenyl-1-methyl-1-cyclohexene-, (R)-; (R)-Limonene; (+)-Dipentene; (4R)-(+)-Limonene; (4R)-Limonene; (R)-(+)-p-Mentha-1,8-diene; (R)-p-Mentha-1,8-diene; Biogenic SE 374; Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (4R)-; EC 7; Glidesafe; Glidsafe; Refchole;carvene;D-citrene;(+)-limonene;(+)-(4R)-limonene;(+)-alpha-limonene;(+)-R-    limonene;(4R)-(+)-limonene;(R)-(+)-limonene;citrus D-limonene;D-limonene;D'limonene;D'limonene;D'limonene (high purity, low odor);D-limonene citreatt;limonene D pure;limonene dextro redistilled;D-limonene high purity low odor;D-limonene natural;D'limonene natural;dextro-limonene natural;D-limonene P&F;limonene R+ SP natural;limonene R+ ST;D-limonene Rectified;dextro-limonene redistilled;(+)-p-    mentha-1,8-diene;(+)-para-    mentha-1,8-diene;(R)-(+)-para-    mentha-1,8-diene;D-para- mentha-1,8-diene;dextro-para-    mentha-1,8-diene;(+)-1,8-para-    menthadiene;1,8 9-p-    menthadiene;1,8 9-para- menthadiene;(R)-1-    methyl-4-(1-methyl ethenyl) cyclohexene;(R)-1-    methyl-4-(1-methyl vinyl) cyclohexene;(R)-1-    methyl-4-(1-methylethenyl)cyclohexene;(R)-1-    methyl-4-(1-methylvinyl)cyclohexene;(R)-1-    methyl-4-isopropenyl-1-cyclohexene;(4R)-1-    methyl-4-prop-1-en-2-ylcyclohexene;(+)-4-iso    propenyl-1-methyl cyclohexene;4-iso    propenyl-1-methyl cyclohexene;(+)-4-iso    propenyl-1-methylcyclohexene;4-iso    propenyl-1-methylcyclohexene;(+)-ALPHA-LIMONENE;BIOGENIC SE 374;CARVENE;(+)-CARVENE;CITRENE;CYCLOHEXENE, 1-METHYL-4-(1-METHYLETHENYL)-, (R)-;D-(+)-LIMONENE;D-LIMONENE;D-P-MENTHA-1,8-DIENE;(+)-DIPENTENE;EC 7;GLIDESAFE;GLIDSAFE;(+)-4-ISOPROPENYL-1-METHYLCYCLOHEXENE;(+)-LIMONENE;LIMONENE, (+)-;NCI-C55572;P-MENTHA-1,8-DIENE;(+)-P-MENTHA-1,8-DIENE;P-MENTHA-1,8-DIENE, (R)-(+)-;(R)-(+)-LIMONENE;(4R)-(+)-LIMONENE;(R)-(+)-P-MENTHA-1,8-DIENE;(R)-1-METHYL-4-(1-METHYLETHENYL)CYCLOHEXENE;(R)-4-ISOPROPENYL-1-METHYL-1-CYCLOHEXENE;(R)-LIMONENE;(+)-(R)-LIMONENE;(+)-(4R)-LIMONENE;(R)-P-MENTHA-1,8-DIENE;(+)-R-LIMONENE;4R-LIMONENE;REFCHOLE;d-p-MENTHA-1,8-DIENE; 4-ISOPROPENYL-1-METHYL-CYCLOHEXENE; 1-METHYL-4- (1-METHYLETHENYL) CYCLOHEXENE;(-)-(S)-Limonene;(-)-(4S)-Limonene;(-)-Limonene;(4S)-1-Methyl-4-isopropenylcyclohex-1-ene;(4S)-4-Isopropenyl-1-methylcyclohexene;(S)-(-)-P-Mentha-1,8-diene;(S)-1-Methyl-4-(1-methylethenyl)cyclohexene;(S)-P-Mentha-1,8-diene;4AlphaH-P-mentha-1,8-diene;L-Limonen;L-Limonene;4-Isopropenyl-1-methyl-1-cyclohexene;Limonene;(+)-Limonene;AISA 5203-L (+)limonene;Dipentene;1-Methyl-4-(1-methylethenyl)cyclohexene;Limonene, (+-)-isomer;(D)-Limonene;4-Mentha-1,8-diene;Limonene, (S)-isomer;Limonene, (R)-isomer;(+)-Dipentene; (R)-4-isopropenyl-1-methyl-1-cyclohexene; D-limonene;d-(+)-limonene; D-(+)-limonene; (+)-limonene; (+)-?-limonene; (+)-(R)-limonene;(+)-(4R)-limonene; (R)-limonene; (R)-(+)-limonene; (4R)-(+)-limonene; (+)-paramentha-1,8-diene;(R)-p-mentha-1,8-diene; (R)-(+)-para-mentha-1,8-diene;carvene : (+)- limonene : (+)-(4R)- limonene : (+)-alpha- limonene : (+)-R- limonene : (4R)-(+)- limonene : (R)-(+)- limonene : (+)-para- mentha-1,8-diene : (R)-(+)-para- mentha-1,8-diene : dextro-para- mentha-1,8-diene : (+)-1,8-para- menthadiene : 1,8 9-para- menthadiene : (R)-1- methyl-4-(1-methyl ethenyl) cyclohexene : (R)-1- methyl-4-(1-methyl vinyl) cyclohexene : (R)-1- methyl-4-isopropenyl-1-cyclohexene : (4R)-1- methyl-4-prop-1-en-2-ylcyclohexene : (+)-4-iso propenyl-1-methyl cyclohexene : 4-iso propenyl-1-methyl cyclohexene : Berje : dextro-Limonene : Berje : dextro-Limonene Redistilled : Citrus and Allied Essences : D'Limonene : Citrus and Allied Essences : D'Limonene (high purity, low odor) : Fleurchem : dextro-limonene natural : Fleurchem : dextro-limonene : Global Essence : dextro-LIMONENE : Moellhausen : limonene R+ SP 95pc min. natural kosher;Terpene Hydrocarbons NOS;Orange oil, terpenes;Terpenes and terpenoids, orange oil;Sweet orange, peel, tincture;Orange, sweet, extract;Limonene-D;1-methyl-4-(1-methylethenyl)cyclohexene, (R); l-Limonene; d-Limonene; dl-Limonene; Dipentene; Acintene DP; Cinene; Dipanol; Unitene; 1-methyl-4-isopropentyl-1-cyclohexene ;d-Limonene;(+)-Limonene;(+)-(R)-Limonene;(+)-(4R)-Limonene;LEMOSOL;POLY/CLEAR SOLVENT;(+)-(4R)-Limonene;(+)-1,8-p-menthadiene,(R)-(+)-limonene;(+)-4-isopropenyl-1-methylcyclohexene;(+)-limonen;(4R)-(+)-limonene;(gamma)-Carvene;(R)-(+)-1-methyl-4-(1-methylethenyl)cyclohexene,(r)-(+)-p-mentha-8-diene;(R)-1-methyl-4-(1-methylethenyl)cyclohexene;(r)-cyclohexen;(theta)-cyclohexen;1-methyl-4-(1-methylethenyl)-,(R)-Cyclohexene;4-isopropenyl-1-methyl-cyclohexen;4-isopropenyl-1-methylcyclohexene;citrene;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (R)-;cyclohexene,1-methyl-4-(1-methylethenyl)-,(R)-;Dextro-limonene;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (R)-; p-Mentha-1,8-diene, (R)-(+)-; (+)-(R)-Limonene; (+)-(4R)-Limonene; (+)-p-Mentha-1,8-diene; (+)-Limonene; (R)-(+)-Limonene; Carvene; D-(+)-Limonene; Limonene, (D)-; Limonene, (+)-; (R)-1-methyl-4-(1-methylethenyl)cyclohexene; Dextro-limonene; (R)-4-Isopropenyl-1-methyl-1-cyclohexene; 4-Isopropenyl-1-methyl-1-cyclohexene-, (R)-; (R)-Limonene; (+)-Dipentene; (4R)-(+)-Limonene; (4R)-Limonene; (R)-(+)-p-Mentha-1,8-diene; (R)-p-Mentha-1,8-diene; Biogenic SE 374; Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (4R)-; EC 7; Glidesafe; Glidsafe; Refchole;(+)-p-Mentha-1,8-diene; (+)-?-Limonene; (4R)-(+)-Limonene; (4R)-1-Methyl-4-(1-methylethenyl)cyclohexene; (4R)-Limonene; (R)-(+)-Limonene; (R)-(+)-p-Mentha-1,8-diene; (R)-4-Isopropenyl-1-methyl-1-cyclohexene; (R)-Limonene; (R)-p-Mentha-1,8-diene; 1-Methyl-4-prop-1-en-2-yl-cyclohexene; Bio Clear; Biogenic SE 374; Carvene; Clearene; D-(+)-Limonene; D-Limonene; EC 7; Fruits Dry; Glidesafe; Glidsafe; Histo-Clear; HistoSolve X; Limonene, (+)-; Master Clear; NK 1100; Refchole; Safsolv; Woody River 8; d-(+)-Limonene; d-Limonene; (R)-1-Methyl-4-(1-methylethenyl)cyclohexene; (R)-(+)-p-Mentha-1,8-diene; (+)-(4R)-Limonene; (+)-(R)-Limonene; (+)-Dipentene;(+)-Limonene;(+/-)-Limonene;(R)-(+)-Limonene;1-methyl-4-prop-1-en-2-ylcyclohexene;4-isopropenyl-1-methylcyclohexene;Cinene;Dipentene;Dipentene, technical grade;A-11638;A-25620;AGN-PC-014NSB;AY126431;DIV 03713;EN300-21627;L0046;QE-8187;T1295;T3241;DLIMONENE;d-limonene;dlimonene;d limonen; d-limonen; D LIMONEN;  LİMONEN;  lımonen; lımonen; Lımonen;  limon; limonen  LIMON; limonen 

Limonene

Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels.[1] The d-isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring agent in food manufacturing.[1][2] It is also used in chemical synthesis as a precursor to carvone and as a renewables-based solvent in cleaning products.[1] The less common l-isomer is found in mint oils and has a piny, turpentine-like odor.[1] The compound is one of the main volatile monoterpenes found in the resin of conifers, particularly in the Pinaceae, and of orange oil.

Limonene takes its name from French limon ("lemon").[3] Limonene is a chiral molecule, and biological sources produce one enantiomer: the principal industrial source, citrus fruit, contains d-limonene ((+)-limonene), which is the (R)-enantiomer.[1] Racemic limonene is known as dipentene.[4] d-Limonene is obtained commercially from citrus fruits through two primary methods: centrifugal separation or steam distillation.

Chemical reactions
Limonene is a relatively stable monoterpene and can be distilled without decomposition, although at elevated temperatures it cracks to form isoprene.[5] It oxidizes easily in moist air to produce carveol, carvone, and limonene oxide.[1][6] With sulfur, it undergoes dehydrogenation to p-cymene.[7]

Limonene occurs commonly as the d- or (R)-enantiomer, but racemizes to dipentene at 300 °C. When warmed with mineral acid, limonene isomerizes to the conjugated diene α-terpinene (which can also easily be converted to p-cymene). Evidence for this isomerization includes the formation of Diels–Alder adducts between α-terpinene adducts and maleic anhydride.

It is possible to effect reaction at one of the double bonds selectively. Anhydrous hydrogen chloride reacts preferentially at the disubstituted alkene, whereas epoxidation with mCPBA occurs at the trisubstituted alkene.

In another synthetic method Markovnikov addition of trifluoroacetic acid followed by hydrolysis of the acetate gives terpineol.

Biosynthesis
In nature, limonene is formed from geranyl pyrophosphate, via cyclization of a neryl carbocation or its equivalent as shown.[8] The final step involves loss of a proton from the cation to form the alkene.

D-Limonene

Not to be confused with Lemonene.
D-Limonene
Skeletal structure of the (R)-isomer
Ball-and-stick model of the (R)-isomer
rotating 3d D-Limonene molecule
D-Limonene extracted from orange peels.
Names
Preferred IUPAC name
1-Methyl-4-(prop-1-en-2-yl)cyclohex-1-ene
Other names
1-Methyl-4-(1-methylethenyl)cyclohexene
4-Isopropenyl-1-methylcyclohexene
p-Menth-1,8-diene
Racemic: DL-D-Limonene; Dipentene
Identifiers
CAS Number
138-86-3 (R/S) ☒
5989-27-5 (R) ☒
5989-54-8 (S) ☒
3D model (JSmol)
Interactive image
ChEBI    
CHEBI:15384 ☑
ChEMBL    
ChEMBL449062 (R) ☒
ChemSpider    
20939 (R/S) ☑
388386 (S) ☑
389747 (R) ☑
ECHA InfoCard    100.028.848
KEGG    
D00194 ☑
PubChem CID
22311 (R/S)
439250 (S)
UNII    
9MC3I34447 (R/S) ☒
GFD7C86Q1W (R) ☒
47MAJ1Y2NE (S) ☒
CompTox Dashboard (EPA)
DTXSID2029612 Edit this at Wikidata
InChI[show]
SMILES[show]
Properties
Chemical formula
C10H16
Molar mass    136.238 g·mol−1
Appearance    colorless to pale-yellow liquid
Odor    Orange
Density    0.8411 g/cm3
Melting point    −74.35 °C (−101.83 °F; 198.80 K)
Boiling point    176 °C (349 °F; 449 K)
Solubility in water
Insoluble
Solubility    Miscible with benzene, chloroform, ether, CS2, and oils
soluble in CCl4
Chiral rotation ([α]D)
87–102°
Refractive index (nD)
1.4727
Thermochemistry
Std enthalpy of
combustion (ΔcH⦵298)
−6.128 MJ mol−1
Hazards
Main hazards    Skin sensitizer / Contact dermatitis – After aspiration, pulmonary oedema, pneumonitis, and death[1]
GHS pictograms    GHS02: FlammableGHS07: HarmfulGHS08: Health hazardGHS09: Environmental hazard
GHS Signal word    Danger
GHS hazard statements
H226, H304, H315, H317, H400, H410
GHS precautionary statements
P210, P233, P240, P241, P242, P243, P261, P264, P272, P273, P280, P301+330+331, P302+352, P303+361+353, P304+340, P312, P333+313, P362, P370+378, P391, P403+233, P235, P405, P501
NFPA 704 (fire diamond)    
NFPA 704 four-colored diamond
230
Flash point    50 °C (122 °F; 323 K)
Autoignition
temperature
237 °C (459 °F; 510 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
D-Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels.[1] The D-isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring agent in food manufacturing.[1][2] It is also used in chemical synthesis as a precursor to carvone and as a renewables-based solvent in cleaning products.[1] The less common L-isomer is found in mint oils and has a piny, turpentine-like odor.[1] The compound is one of the main volatile monoterpenes found in the resin of conifers, particularly in the Pinaceae, and of orange oil.

D-Limonene takes its name from French limon ("lemon").[3] D-Limonene is a chiral molecule, and biological sources produce one enantiomer: the principal industrial source, citrus fruit, contains D-D-Limonene ((+)-D-Limonene), which is the (R)-enantiomer.[1] Racemic D-Limonene is known as dipentene.[4] D-D-Limonene is obtained commercially from citrus fruits through two primary methods: centrifugal separation or steam distillation.

Chemical reactions
D-Limonene is a relatively stable monoterpene and can be distilled without decomposition, although at elevated temperatures it cracks to form isoprene.[5] It oxidizes easily in moist air to produce carveol, carvone, and D-Limonene oxide.[1][6] With sulfur, it undergoes dehydrogenation to p-cymene.[7]

D-Limonene occurs commonly as the D- or (R)-enantiomer, but racemizes to dipentene at 300 °C. When warmed with mineral acid, D-Limonene isomerizes to the conjugated diene α-terpinene (which can also easily be converted to p-cymene). Evidence for this isomerization includes the formation of Diels–Alder adducts between α-terpinene adducts and maleic anhydride.

It is possible to effect reaction at one of the double bonds selectively. Anhydrous hydrogen chloride reacts preferentially at the disubstituted alkene, whereas epoxidation with mCPBA occurs at the trisubstituted alkene.

In another synthetic method Markovnikov addition of trifluoroacetic acid followed by hydrolysis of the acetate gives terpineol.

Biosynthesis
In nature, D-Limonene is formed from geranyl pyrophosphate, via cyclization of a neryl carbocation or its equivalent as shown.[8] The final step involves loss of a proton from the cation to form the alkene.

center[Biosynthesis of D-Limonene from geranyl pyrophosphate

The most widely practiced conversion of D-Limonene is to carvone. The three-step reaction begins with the regioselective addition of nitrosyl chloride across the trisubstituted double bond. This species is then converted to the oxime with a base, and the hydroxylamine is removed to give the ketone-containing carvone.[2]

In plants
D-Limonene is a major component of the aromatic scents and resins characteristic for numerous coniferous and broadleaved trees: red and silver maple (Acer rubrum, Acer saccharinum), cottonwoods (Populus angustifolia), aspens (Populus grandidentata, Populus tremuloides) sumac (Rhus glabra), spruce (Picea spp.), various pines (examples, Pinus echinata, Pinus ponderosa), Douglas fir (Pseudotsuga menziesii), larches (Larix spp.), true firs (Abies spp.), hemlocks (Tsuga spp.), cannabis (Cannabis sativa spp.),[9] cedars (Cedrus spp.), various Cupressaceae and juniper bush (Juniperus spp.).[1] It contributes to the characteristic odor of orange peel, orange juice and other citrus fruits.[1][10] To optimize recovery of valued components from citrus peel waste, d-limonene is typically removed.[11]

Safety and research
D-Limonene applied to skin may cause irritation from contact dermatitis, but otherwise appears to be safe for human uses.[12][13] D-Limonene is flammable as a liquid or vapor and it is toxic to aquatic life.[1]

Uses
D-Limonene is common as a dietary supplement and as a fragrance ingredient for cosmetics products.[1] As the main fragrance of citrus peels, D-limonene is used in food manufacturing and some medicines, such as a flavoring to mask the bitter taste of alkaloids, and as a fragrance in perfumery, aftershave lotions, bath products, and other personal care products.[1] D-Limonene is also used as a botanical insecticide.[1][14] D-Limonene is used in the organic herbicide "Avenger".[15] It is added to cleaning products, such as hand cleansers to give a lemon or orange fragrance (see orange oil) and for its ability to dissolve oils.[1] In contrast, L-limonene has a piny, turpentine-like odor.

D-Limonene is used as a solvent for cleaning purposes, such as adhesive remover, or the removal of oil from machine parts, as it is produced from a renewable source (citrus essential oil, as a byproduct of orange juice manufacture).[11] It is used as a paint stripper and is also useful as a fragrant alternative to turpentine. D-Limonene is also used as a solvent in some model airplane glues and as a constituent in some paints. Commercial air fresheners, with air propellants, containing D-Limonene are used by philatelists to remove self-adhesive postage stamps from envelope paper.[16]

D-Limonene is also used as a solvent for fused filament fabrication based 3D printing.[17] Printers can print the plastic of choice for the model, but erect supports and binders from HIPS, a polystyrene plastic that is easily soluble in D-Limonene. As it is combustible, D-Limonene has also been considered as a biofuel.[18]

In preparing tissues for histology or histopathology, D-D-Limonene is often used as a less toxic substitute for xylene when clearing dehydrated specimens. Clearing agents are liquids miscible with alcohols (such as ethanol or isopropanol) and with melted paraffin wax, in which specimens are embedded to facilitate cutting of thin sections for microscopy.[19][20][21]

See also
Monoterpenes
Resin
Essential oil

D-Limonene is the oil extracted from the peels of oranges and other citrus fruits (1).

People have been extracting essential oils like D-Limonene from citrus fruits for centuries. Today, D-Limonene is often used as a natural treatment for a variety of health issues and is a popular ingredient in household items.

However, not all of D-Limonene’s benefits and uses are supported by science.

This article examines D-Limonene’s uses, potential benefits, side effects, and dosage.

What is D-Limonene?
D-Limonene is a chemical found in the rind of citrus fruits, such as lemons, limes, and oranges. It is especially concentrated in orange peels, comprising around 97% of this rind’s essential oils (2Trusted Source).

It’s often referred to as d-Limonene, which is its main chemical form.

D-Limonene belongs to a group of compounds known as terpenes, whose strong aromas protect plants by deterring predators (3Trusted Source).

D-Limonene is one of the most common terpenes found in nature and may offer several health benefits. It has been shown to possess anti-inflammatory, antioxidant, anti-stress, and possibly disease-preventing properties.

SUMMARY
D-Limonene is an essential oil found in citrus fruit peels. It belongs to a class of compounds called terpenes.
Common uses of D-Limonene
D-Limonene is a popular additive in foods, cosmetics, cleaning products, and natural insect repellants. For example, it’s used in foods like sodas, desserts, and candies to provide a lemony flavor.

D-Limonene is extracted through hydrodistillation, a process in which fruit peels are soaked in water and heated until the volatile molecules are released via steam, condensed, and separated (4).

Due to its strong aroma, D-Limonene is utilized as a botanical insecticide. It’s an active ingredient in multiple pesticide products, such as eco-friendly insect repellents (5).

Other household products containing this compound include soaps, shampoos, lotions, perfumes, laundry detergents, and air fresheners.

Additionally, D-Limonene is available in concentrated supplements in capsule and liquid form. These are often marketed for their supposed health benefits.

This citrus compound is also used as an aromatic oil for its calming and therapeutic properties.

SUMMARY
D-Limonene is used in a range of products, including food, cosmetics, and eco-friendly pesticides. It can also be found in supplement form, as it may boost health and fight certain diseases.
Linked to several health benefits
D-Limonene has been studied for its potential anti-inflammatory, antioxidant, anticancer, and heart-disease-fighting properties.

However, most research has been conducted in test tubes or on animals, making it difficult to fully understand the role of D-Limonene in human health and disease prevention.

Anti-inflammatory and antioxidant benefits
D-Limonene has been shown to reduce inflammation in some studies (6Trusted Source, 7Trusted Source).

While short-term inflammation is your body’s natural response to stress and is beneficial, chronic inflammation can harm your body and is a major cause of illness. It’s important to prevent or reduce this type of inflammation as much as possible (8Trusted Source).

D-Limonene has been shown to reduce inflammatory markers that relate to osteoarthritis, a condition characterized by chronic inflammation.

A test-tube study in human cartilage cells noted that D-Limonene reduced nitric oxide production. Nitric oxide is a signaling molecule that plays a key role in inflammatory pathways (9Trusted Source).

In a study in rats with ulcerative colitis — another disease characterized by inflammation — treatment with D-Limonene significantly decreased inflammation and colon damage, as well as common inflammatory markers (10Trusted Source).

D-Limonene has demonstrated antioxidant effects as well. Antioxidants help reduce cell damage caused by unstable molecules called free radicals.

Free radical accumulation can lead to oxidative stress, which may trigger inflammation and disease (11Trusted Source).

One test-tube study revealed that D-Limonene may inhibit free radicals in leukemia cells, suggesting a decrease in inflammation and cellular damage that would normally contribute to disease (12Trusted Source).

Although promising, these effects need to be confirmed by human studies.

May have anticancer effects
D-Limonene may have anticancer effects.

In a population study, those who consumed citrus fruit peel, the major source of dietary D-Limonene, had a reduced risk of developing skin cancer compared to those who only consumed citrus fruits or their juices (13Trusted Source).

Another study in 43 women recently diagnosed with breast cancer experienced a significant 22% reduction in breast tumor cell expression after taking 2 grams of D-Limonene daily for 2–6 weeks (14Trusted Source).

Additionally, research in rodents found that supplementing with D-Limonene inhibited the growth of skin tumors by preventing inflammation and oxidative stress (15Trusted Source).

Other rodent studies indicate that D-Limonene may fight other types of cancer, including breast cancer (16Trusted Source).

What’s more, when given to rats alongside the anticancer drug doxorubicin, D-Limonene helped prevent several common side effects of the medication, including oxidative damage, inflammation, and kidney damage (17Trusted Source).

Although these results are promising, more human studies are needed.

May boost heart health
Heart disease remains the leading cause of death in the United States, accounting for nearly one in four deaths (18Trusted Source).

D-Limonene may lower your risk of heart disease by reducing certain risk factors, such as elevated cholesterol, blood sugar, and triglyceride levels.

In one study, mice given 0.27 grams of D-Limonene per pound of body weight (0.6 grams/kg) showed reduced triglycerides, LDL (bad) cholesterol, fasting blood sugar, and fat accumulation in the liver, compared to a control group (19Trusted Source).

In another study, stroke-prone rats given 0.04 grams of D-Limonene per pound of body weight (20 mg/kg) exhibited significant reductions in blood pressure compared to rats of similar health status that did not receive the supplement (20Trusted Source).

Keep in mind that human studies are needed before strong conclusions can be drawn.

Other benefits
Aside from the benefits listed above, D-Limonene may:

Reduce appetite. The scent of D-Limonene has been shown to significantly reduce appetite in blowflies. However, this effect has not been studied in humans (21Trusted Source).
Decrease stress and anxiety. Rodent studies suggest that D-Limonene could be used in aromatherapy as an anti-stress and anti-anxiety agent (22Trusted Source).
Support healthy digestion. D-Limonene may protect against stomach ulcers. In a study in rats, citrus aurantium oil, which is 97% D-Limonene, protected nearly all of the rodents against ulcers caused by medication use (23Trusted Source).
SUMMARY
D-Limonene may offer antioxidant, anti-inflammatory, anticancer, and anti-heart-disease benefits, among others. However, more research in humans is needed.
Safety and side effects
D-Limonene is considered safe for humans with little risk of side effects. The Food and Drug Administration (FDA) recognizes D-Limonene as a safe food additive and flavoring (5).

However, when applied directly to the skin, D-Limonene may cause irritation in some people, so caution should be used when handling its essential oil (24Trusted Source, 25).

D-Limonene is sometimes taken as a concentrated supplement. Because of the way your body breaks it down, it’s likely safe consumed in this form. That said, human research on these supplements is lacking (26Trusted Source).

Notably, high-dose supplements may cause side effects in some people. What’s more, insufficient evidence exists to determine whether D-Limonene supplements are acceptable for pregnant or breastfeeding women.

It’s best to consult your healthcare practitioner before taking D-Limonene supplements, especially if you’re taking medications, are pregnant or breastfeeding, or have a medical condition.

SUMMARY
Aside from possible skin irritation associated with direct application, D-Limonene is likely safe for most people to use and consume in moderation.

Potentially effective dosages
Because few D-Limonene studies exist in humans, it’s difficult to provide a dosage recommendation.

Nonetheless, dosages of up to 2 grams daily have been safely used in studies (9Trusted Source, 14Trusted Source).

Capsule supplements that can be purchased online contain dosages of 250–1,000 mg. D-Limonene is also available in liquid form with typical dosages of 0.05 ml per serving.

However, supplements aren’t always necessary. You can easily obtain this compound by eating citrus fruits and peels.

For example, fresh orange, lime, or lemon zest can be used to add D-Limonene to baked goods, drinks, and other items. What’s more, pulpy citrus juices, such as lemon or orange juice, boast D-Limonene, too (27Trusted Source).

SUMMARY
While dosage recommendations don’t exist for D-Limonene, 2 grams daily has been safely used in studies. In addition to supplements, you can obtain D-Limonene from citrus fruits and zest.
The bottom line
D-Limonene is a compound extracted from the peels of citrus fruits.

Studies suggest that D-Limonene may have anti-inflammatory, antioxidant, and anticancer effects. However, more research in humans is needed to confirm these benefits.

Try adding lemon, lime, or orange zest to your favorite dishes to boost your D-Limonene intake.

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D-D-Limonene is a compound sourced from the peel of citrus fruits, including include oranges, mandarins, limes, and grapefruit. It takes its name from the lemon and is often used as a flavoring agent in foods. D-D-Limonene differs from a less common type of D-Limonene known as L-D-Limonene, which is found in mint oil.

Sold as a dietary supplement, D-D-Limonene is said to offer a variety of health benefits, in part because of its ability to dissolve fats, including cholesterol. Proponents believe that D-D-Limonene can not only aid in weight loss but treat or prevent certain diseases, including cancer.

Health Benefits
Alternative practitioners have long touted the benefits of D-D-Limonene, claiming that it not only burns fat but reduces inflammation and kills disease-causing germs. Many of these beliefs are culled from its use in industry, where D-D-Limonene is commonly used to make hand sanitizers, perfumes, botanical pesticides, and chemical solvents.

Among some of the conditions that D-D-Limonene is believed to prevent or treat are:

Bronchitis
Cancer
Diabetes
Gallstones
Gastroesophageal reflux disease (GERD)
Heartburn
High cholesterol
Inflammatory bowel disease (IBD)
Metabolic syndrome
Obesity
Peptic ulcers

Citrus essential oils rich in D-D-Limonene are also used in aromatherapy to relieve stress.

To date, there is little solid evidence that D-D-Limonene can treat any medical condition. With that said, a number of preliminary studies have hinted at benefits that may warrant further investigation.

Weight Loss
There is some evidence that D-Limonene can promote weight loss by lowering blood sugar and lipids associated with metabolic syndrome. A 2013 study in the European Journal of Pharmacology reported that obese mice fed a high-diet diet supplemented with D-Limonene experienced decreases in blood glucose, total cholesterol, and "bad" LDL cholesterol as well as increases in "good" HDL cholesterol.

These findings suggest that D-limonene may be useful in preventing or treating metabolic syndrome, although it is unclear what dose would be needed to achieve such benefit in humans. Further research is needed.

Peptic Ulcers
D-limonene may help reduce the risk of peptic ulcers and other inflammatory gastrointestinal diseases, suggests a 2009 study published in the Chemico-Biological Interactions. According to the researchers, high concentrations of D-limonene in the essential oil of bitter orange (C. aurantium) served to protect the lining of the stomach of lab rats fed high-doses of alcohol and nonsteroidal anti-inflammatory drugs (NSAIDs).

Contrary to popular belief, it did so not by suppressing stomach acid but by increasing the production of gastric mucus.

Despite the positive findings, it is unclear if D-limonene did so on its own or if some other component in the essential oil contributed. Further research is needed.

Treating Peptic Ulcers With Diet
Cancer
Alternative practitioners have long touted the anticancer properties of D-limonene. The effect of is attributed to a substance known as perillic acid, which is released into the bloodstream when D-limonene is broken down by the body.

A number of test-tube studies have reported that D-D-Limonene applied to cancer cells can trigger apoptosis (programmed cell death). This is considered significant given that apoptosis—a naturally occurring event that allows old cells to be replaced by new cells—does not occur with cancer cells. This effect was seen in recent studies involving colon cancer,1 skin cancer,2 and other common malignancies.

It remains unclear whether taking D-limonene by mouth might render the same benefit. A 2013 study in Cancer Prevention Research aimed to evaluate this effect by providing 43 women with breast cancer with 2 grams of D-limonene daily for two to six weeks.

At the end of the study period, a biopsy of breast tissue showed high concentrations of D-limonene but little of the perillic acid needed to arrest cancer growth. Further research is needed to determine whether higher doses or longer treatment may help improve these results.

Can Green Tea Prevent Colon Cancer?
Possible Side Effects
Widely used as a food flavoring, D-limonene is generally considered safe and has been used for up to a year in clinical research without incidence. Common side effects include stomach upset and reflux.

At excessively high doses, D-limonene has been known to hematuria (blood in urine).3

D-limonene may cause irritation if applied to the skin. This includes citrus essential oils that are characteristically high in D-limonene. To reduce irritation, always mix essential oils with a carrier oil (such as avocado oil or sweet almond oil) if you intend to use it for massage purposes.

The safety of D-limonene has not been established in children, pregnant women, or nursing mother. As a precaution, always speak with your doctor before using D-limonene or any other supplement if you are pregnant or breastfeeding. As the benefits of D-limonene in children is unknown, it is best to play it safe and avoid the supplement altogether.

Interactions
D-limonene is broken down by many of the same liver enzymes—called cytochrome P450 (CYP450)—that other drugs use for metabolization. Because of this, D-limonene may increase or decrease the concentration of certain drugs as they compete for the same enzyme.

Possible drug-drug interactions include:

Anticoagulants like Coumadin (warfarin)
Anticonvulsants like Tegretol (carbamazepine)
Antifungal drugs like Nizoral (ketoconazole)
Anti-hypertensive medications like Cozaar (losartan)
Antipsychotic drugs like Orap (pimozide)
Atypical antidepressants like nefazodone
Benzodiazepine tranquilizers like Halcion (triazolam)
H2 blockers like Tagamet (cimetidine)
Macrolide antibiotics like clarithromycin and telithromycin
Nonsteroid anti-inflammatory drugs (NSAIDs) like Advil (ibuprofen) and Voltaren (diclofenac)
Proton pump inhibitors like Prilosec (omeprazole)

Many of these interactions can be mitigated by separating the doses by two to four hours. Others may require a dose adjustment or substitution.

To avoid interactions, always advise your doctor about any medications you are taking, whether they are prescription, over-the-counter, nutritional, herbal, or recreational.

Dosage and Preparations
D-limonene supplements are most often sold in soft gel capsules and are easily sourced online or in stores specializing in dietary supplements.

While there are no guidelines for the appropriate use of D-limonene, most manufacturers recommend a dose of between 500 milligrams (mg) and 1,000 mg per day, taken with or without food.

As a rule of thumb, never exceed the dose on the product label. There is no evidence that higher doses confer to improved health benefits.

Most D-limonene soft gels can be stored safely at room temperature. You can also keep them in the refrigerator if there is a risk of heat exposure. Never use a supplement past its expiration date, and dispose of any soft gels that are either leaking, discolored, or misshapen.

What to Look For
Because dietary supplements are not strictly regulated in the United States, it can be difficult to tell which brands are good and which are not.

One way to do so is to choose brands that have been tested by an independent certifying body like the U.S. Pharmacopeia (USP), NSF International, or ConsumerLab.

Certification doesn't mean that the supplement is either safe or effective; it simply indicates that it contains the ingredients listed on the product label and in the correct amounts.

Always check the product label for ingredients you may be sensitive to, including preservatives and gluten. If you are strictly vegetarian or vegan, opt for soft gels made with vegetable-based gelatin rather than animal-based gelatins made from beef or pork cartilage.

EC Number: 227-813-5

IUPAC Name
(4R)-1-methyl-4-prop-1-en-2-ylcyclohexene

Molecular Formula
C10H16

Physical Description
PHYSICAL DESCRIPTION: Clear colorless mobile liquid with a pleasant lemon-like odor.

Odor
Citrus odor

Taste
FRESH, CITRUS TASTE

Limonene, (+)- is an oral dietary supplement containing a natural cyclic monoterpene and major component of the oil extracted from citrus peels with potential chemopreventive and antitumor activities. Although the mechanism of action has yet to be fully elucidated, limonene and its metabolites perillic acid, dihydroperillic acid, uroterpenol and limonene 1,2-diol may inhibit tumor growth through inhibition of p21-dependent signaling and may induce apoptosis via the induction of the transforming growth factor beta-signaling pathway. In addition, they inhibit post-translational modification of signal transduction proteins, resulting in G1 cell cycle arrest as well as differential expression of cell cycle- and apoptosis-related genes.

 

Limonene is a monoterpene with a clear colourless liquid at room temperature, a naturally occurring chemical which is the major component in oil of oranges. Limonene is widely used as a flavor and fragrance and is listed to be generally recognized as safe in food by the Food and Drug Administration (21 CFR 182. 60 in the Code of Federal Regulations, U. S. A. ). Limonene is a botanical (plant-derived) solvent of low toxicity. Mild skin irritation may occur from exposure to limonene and oxidation products of limonene may produce dermal sensitization, and may have irritative and bronchoconstrictive airway effects; however, data are scant and more studies are required. Limonene has been shown to cause a male rat-specific kidney toxicity referred to as hyaline droplet nephropathy. Furthermore, chronic exposure to limonene causes a significant incidence of renal tubular tumors exclusively in male rats. Limonene is one of the active components of dietary phytochemicals that appears to be protective against cancer. (PMID: 16563357, 15499193, 15325315, 2024047).

PHYSICAL DESCRIPTION: Clear colorless mobile liquid with a pleasant lemon-like odor

D-Limonene is a molecule that is found in high levels in lemons (where it derives its name) but also most citrus foods. It holds promise as an anti-cancer agent, and for some reason is marketed as a fat burner despite minimal evidence of fat burning effects. Can be consumed via pulpy lemon juice.

The monoterpene d-limonene is a naturally occurring chemical which is the major component in oil of orange. Currently, d-limonene is widely used as a flavor and fragrance and is listed to be generally recognized as safe in food by the Food and Drug Administration. Recently, however, d-limonene has been shown to cause a male rat-specific kidney toxicity referred to as hyaline droplet nephropathy. Furthermore, chronic exposure to d-limonene causes a significant incidence of renal tubular tumors exclusively in male rats. Although d-limonene is not carcinogenic in female rats or male and female mice given much higher dosages, the male rat-specific nephrocarcinogenicity of d-limonene may raise some concern regarding the safety of d-limonene for human consumption. A considerable body of scientific data has indicated that the renal toxicity of d-limonene results from the accumulation of a protein, alpha 2u-globulin, in male rat kidney proximal tubule lysosomes. This protein is synthesized exclusively by adult male rats. Other species, including humans, synthesize proteins that share significant homology with alpha 2u-globulin. However, none of these proteins, including the mouse equivalent of alpha 2u-globulin, can produce this toxicity, indicating a unique specificity for alpha 2u-globulin. With chronic exposure to d-limonene, the hyaline droplet nephropathy progresses and the kidney shows tubular cell necrosis, granular cast formation at the corticomedullary junction, and compensatory cell proliferation. Both d-limonene and cis-d-limonene-1,2-oxide (the major metabolite involved in this toxicity) are negative in vitro mutagenicity screens. Therefore, the toxicity-related renal cell proliferation is believed to be integrally involved in the carcinogenicity of d-limonene as persistent elevations in renal cell proliferation may increase fixation of spontaneously altered DNA or serve to promote spontaneously initiated cells. The scientific data base demonstrates that the tumorigenic activity of d-limonene in male rats is not relevant to humans. The three major lines of evidence supporting the human safety of d-limonene are the male rat specificity of the nephrotoxicity and carcinogenicity; the pivotal role that alpha 2u-globulin plays in the toxicity, as evidenced by the complete lack of toxicity in other species despite the presence of structurally similar proteins; and the lack of genotoxicity of both d-limonene and d-limonene-1,2-oxide, supporting the concept of a nongenotoxic mechanism, namely, sustained renal cell proliferation.

This compound belongs to the class of chemical entities known as menthane monoterpenoids. These are monoterpenoids with a structure based on the o-, m-, or p-menthane backbone. P-menthane consists of the cyclohexane ring with a methyl group and a (2-methyl)-propyl group at the 1 and 4 ring position, respectively. The o- and m- menthanes are much rarer, and presumably arise by alkyl migration of p-menthanes.