Carvacrol

Carvacrol, or cymophenol, C₆H₃(CH₃)(OH)C₃H₇, is a monoterpenoid phenol. It has a characteristic pungent, warm odor of oregano.^[4]

Carvacrol^[1]

Carvacrol
Names
Preferred IUPAC name 2-Methyl-5-(propan-2-yl)phenol[2]
Systematic IUPAC name 2-Methyl-5-(propan-2-yl)benzenol
Other names Carvacrol 5-Isopropyl-2-methylphenol 2-Methyl-5-(1-methylethyl)phenol Isothymol
Identifiers
CAS Number	499-75-2 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL281202 Y
ChemSpider	21105867 Y
ECHA InfoCard	100.007.173
IUPHAR/BPS	2497
KEGG	C09840 Y
PubChem CID	10364
UNII	9B1J4V995Q Y
CompTox Dashboard (EPA)	DTXSID6042074
InChI InChI=1S/C10H14O/c1-7(2)9-5-4-8(3)10(11)6-9/h4-7,11H,1-3H3 Y Key: RECUKUPTGUEGMW-UHFFFAOYSA-N Y InChI=1/C10H14O/c1-7(2)9-5-4-8(3)10(11)6-9/h4-7,11H,1-3H3 Key: RECUKUPTGUEGMW-UHFFFAOYAI
SMILES Cc1ccc(cc1O)C(C)C
Properties
Chemical formula	C10H14O
Molar mass	150.217 g/mol
Density	0.9772 g/cm3 at 20 °C
Melting point	1 °C (34 °F; 274 K)
Boiling point	237.7 °C (459.9 °F; 510.8 K)
Solubility in water	insoluble
Solubility	soluble in ethanol, diethyl ether, carbon tetrachloride, acetone[3]
Magnetic susceptibility (χ)	−1.091×10−4 cm3/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Natural occurrence

Carvacrol is present in the essential oil of Origanum vulgare (oregano), oil of thyme, oil obtained from pepperwort, and wild bergamot.^[5] The essential oil of thyme subspecies contains between 5% and 75% of carvacrol, while Satureja (savory) subspecies have a content between 1% and 45%.^[6] Origanum majorana (marjoram) and Dittany of Crete are rich in carvacrol, 50% and 60–80% respectively.^[7]

It is also found in tequila^[8] and Lippia graveolens (Mexican oregano) in the verbena family.

Sources

• Coleus amboinicus
• Lavandula multifida
• Lepidium
• Lippia graveolens
• Monarda didyma^[9]
• Monarda fistulosa
• Nigella sativa^[10]
• Origanum compactum^[11]
• Origanum dictamnus^[12]
• Origanum majorana
• Origanum microphyllum^[13]
• Origanum minutiflorum
• Origanum onites^[14][15]
• Origanum scabrum^[13]
• Origanum syriacum^[16]
• Origanum vulgare^[17][18]
• Plectranthus amboinicus
• Satureja
• Satureja thymbra
• tequila
• Thymbra spicata
• oil of thyme
• Thymus glandulosus^[11]

Synthesis and derivatives

Carvacrol may be synthetically prepared by a number of routes. The fusion of cymol sulfonic acid with caustic potash results in desulfonation. By the action of nitrous acid on 1-methyl-2-amino-4-propyl benzene, one effects diazotization. Prolonged heating of camphor and iodine or carvone with glacial phosphoric acid have also been demonstrated. The dehydrogenation of carvone with a palladium-carbon catalyst has been established.^[5]

It has also been prepared by transalkylation of isopropylated cresols.^[19]

It is extracted from Origanum oil by means of a 50% potash solution. It is a thick oil that sets at -20 °C to a mass of crystals of melting point 0 °C, and boiling point 236–237 °C. Oxidation with ferric chloride converts it into dicarvacrol, whilst phosphorus pentachloride transforms it into chlorcymol.^[5]

Antimicrobial effects

In vitro, carvacrol has antimicrobial activity against 25 different phytopathogenic bacteria and strains including:^[20] Cladosporium herbarum,^[20] Penicillium glabrum,^[20] Pseudomonas syringae,^[21] and fungi such as Fusarium verticillioides/F. moniliforme, Rhizoctonia solani/R. solani, Sclerotinia sclerotiorum, and Phytophthora capsici.^[20]

Compendial status

• British Pharmacopoeia^[22]

See also

• Thymol
• Essential oil