Methyl salicylate

Methyl salicylate (oil of wintergreen or wintergreen oil) is an organic compound with the formula C₆H₄(OH)(CO₂CH₃). It is the methyl ester of salicylic acid. It is a colorless, viscous liquid with a sweet, fruity odor reminiscent of root beer, but often associatively called "minty," as it is an ingredient in mint candies.It is produced by many species of plants, particularly wintergreens. It is also produced synthetically, used as a fragrance, in foods and beverages, and in liniments.

Methyl salicylate is used in high concentrations as a rubefacient and analgesic in deep heating liniments (such as Bengay) to treat joint and muscular pain. Randomised double blind trials report that evidence of its effectiveness is weak, but stronger for acute pain than chronic pain, and that effectiveness may be due entirely to counterirritation. However, in the body it metabolizes into salicylates, including salicylic acid, a known NSAID.

Methyl salicylate is used in low concentrations (0.04% and under) as a flavoring agent in chewing gum and mints. When mixed with sugar and dried, it is a potentially entertaining source of triboluminescence, gaining the tendency to build up electrical charge when crushed or rubbed, which can be observed by crushing wintergreen Life Savers in a dark room.It is used as an antiseptic in Listerine mouthwash produced by the Johnson & Johnson company.It provides fragrance to various products and as an odor-masking agent for some organophosphate pesticides.

Methyl salicylate is also used as a bait for attracting male orchid bees for study, which apparently gather the chemical to synthesize pheromones, and to clear plant or animal tissue samples of color, and as such is useful for microscopy and immunohistochemistry when excess pigments obscure structures or block light in the tissue being examined. This clearing generally only takes a few minutes, but the tissue must first be dehydrated in alcohol.

Additional applications include: used as a simulant or surrogate for the research of chemical warfare agent sulfur mustard, due to its similar chemical and physical properties., in restoring (at least temporarily) the elastomeric properties of old rubber rollers, especially in printers, and as a penetrating oil to loosen rusted parts.