Menthyl Lactate is a chemical compound, a secondary metabolite that is an indispensable molecule for the development and growth of plants. Secondary metabolites also have an important role in plant defense.

Menthyl Lactate is produced by thermophilic bacteria including (1):

• Bacillus sonorensis
• Bacillus thermocopriae
• Brevibacillus borstelensis
• Brevibacillus parabrevis

Menthyl lactate is a compound derived from the esterification of menthol and lactic acid.

The name describes the structure of the molecule:

• Menthyl - This part of the name indicates that the molecule is derived from menthol, an organic compound primarily obtained from peppermint oil. Menthol has a cyclic structure and imparts a cooling sensation when applied to the skin.
• Lactate - This part of the name refers to the ester of menthol with lactic acid. Lactic acid is a carboxylic acid with the formula CH₃CHOHCOOH. When lactic acid reacts with menthol, it forms the ester called menthyl lactate.

Description of the raw materials used in its production:

• Menthol - Menthol is a natural compound derived from mint plants such as peppermint or spearmint. It provides the characteristic cooling sensation and minty aroma.
• Lactic acid - Lactic acid is an organic acid produced through the fermentation of carbohydrates, such as sugars or starches. It can be derived from natural sources like fruits or fermented milk or produced synthetically.

Summary of the industrial synthesis process step-by-step:

• Menthol extraction or synthesis - Menthol can be obtained through the extraction of mint plants or synthesized from other starting materials using chemical processes.
• Preparation of lactic acid - Lactic acid can be produced through fermentation processes using specific strains of bacteria, such as Lactobacillus. Alternatively, it can be chemically synthesized from other precursors.
• Esterification reaction - Menthol and lactic acid are combined and subjected to an esterification reaction. This reaction involves the removal of a water molecule and the formation of a chemical bond between the hydroxyl group of menthol and the carboxyl group of lactic acid.
• Purification - The crude menthyl lactate obtained from the esterification reaction is purified to remove impurities, unreacted starting materials, and by-products.
• Characterization - The synthesized menthyl lactate is characterized through various analytical techniques to confirm its identity, purity, and quality.
• Formulation - Menthyl lactate is incorporated into personal care and cosmetic products such as lotions, creams, and oral care products to provide a refreshing and soothing sensation on the skin or mucous membranes.
• Packaging and distribution - The final product, menthyl lactate, is packaged in suitable containers and distributed for use in various industries.

What it is used for and where

It is commonly used in personal care and cosmetic products for its cooling and refreshing properties.

Food

In the food sector it is added as a flavoring agent.

Cosmetics

Fragrance. It plays a decisive and important role in the formulation of cosmetic products as it provides the possibility of enhancing, masking or adding fragrance to the final product, increasing its marketability.  The consumer always expects to find a pleasant or distinctive scent in a cosmetic product.

Refreshing. This component is included in cosmetic products to provide a refreshing or toning sensation to the skin and can also help relieve irritation or redness.

The most relevant studies on this chemical compound have been selected with a summary of their contents:

Menthyl Lactate studies

• Molecular Formula: C₁₃H₂₄O₃
• Molecular Weight: 228.332 g/mol
• CAS: 59259-38-0   17162-29-7  61597-98-6  
• EC Number:  261-678-3  241-218-8    612-179-8 
• FEMA Number: 3748
• PubChem Substance ID 329830650
• MDL number MFCD09037384
• Flavis number 9.551

Synonyms:

• L-Menthyl Lactate
• l-Menthyl lactate
• (-)-menthyl lactate
• (R)-2-Hydroxypropionic Acid (1R,2S,5R)-2-Isopropyl-5-methylcyclohexyl Ester
• 2-Isopropyl-5-methylcyclohexyl 2-hydroxypropanoate
• 2-Hydroxypropanoic acid 5-methyl-2-(1-methylethyl)cyclohexyl esterPropanoic acid, 2-hydroxy-, 5-methyl-2-(1-methylethyl)cyclohexyl ester
• 5-methyl-2-(propan-2-yl)cyclohexyl 2-hydroxypropanoate
• 2-Isopropyl-5-methylcyclohexyl lactate(S)-(1R,2S,5R)-2-Isopropyl-5-methylcyclohexyl 2-hydroxypropanoate
• 5-Methyl-2-(1-methylethyl)cyclohexyl lactate
• L-Menthyl Lactate, L-Menthyl Ester of Lactic Acid
• (2-isopropyl-5-methyl-cyclohexyl) 2-hydroxypropanoate
• (5-methyl-2-propan-2-ylcyclohexyl) 2-hydroxypropanoate
• propanoic acid,2-hydroxy-,5-methyl-2-(1-methylethyl)cyclohexyl ester

References__________________________________________________________________

(1) Alrumman, S.A., Mostafa, Y.S., Al-Qahtani, S.T.S. et al.   Activity and GC-MS Analysis of Bioactive Constituents of Thermophilic Bacteria Isolated from Saudi Hot Springs
Arab J Sci Eng (2019) 44: 75. https://doi.org/10.1007/s13369-018-3597-0