Carvacrol

Carvacrol, or cymophenol, C6H3(CH3)(OH)C3H7, is a monoterpenoid phenol. It has a characteristic pungent, warm odor of oregano.
Natural occurrence.
Carvacrol is present in the essential oil of "Origanum vulgare" (oregano), oil of thyme, oil obtained from pepperwort, and wild bergamot. The essential oil of thyme subspecies contains between 5% and 75% of carvacrol, while "Satureja" (savory) subspecies have a content between 1% and 45%. "Origanum majorana" (marjoram) and Dittany of Crete are rich in carvacrol, 50% and 60–80% respectively.
It is also found in tequila and "Lippia graveolens" (Mexican oregano) in the verbena family.
Synthesis and derivatives.
Carvacrol may be synthetically prepared by the fusion of cymol sulfonic acid with caustic potash; by the action of nitrous acid on 1-methyl-2-amino-4-propyl benzene; by prolonged heating of five parts of camphor with one part of iodine; or by heating carvol with glacial phosphoric acid or by performing a dehydrogenation of carvone with a palladium-carbon catalyst. 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.
Toxicology.
In vitro, carvacrol has antimicrobial activity against 25 different periodontopathic bacteria and strains including: "Cladosporium herbarum", "Penicillium glabrum", and fungi such as "F. moniliforme", "R. solani", "S. sclerotirum", "P. capisci", and "Pseudomonas syringae".