Methylparaben, also methyl paraben, one of the parabens

Parabens

Parabens are a class of chemicals widely used as preservatives in the cosmetic and pharmaceutical industries. Parabens are effective preservatives in many types of formulas. These compounds, and their salts, are used primarily for their bactericidal and fungicidal properties...

, is a preservative with the chemical formula CH₃(C₆H₄(OH)COO). It is the methyl ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 of p-hydroxybenzoic acid.
Methylparaben is found in several fruits, in particular blueberries

Blueberry

Blueberries are flowering plants of the genus Vaccinium with dark-blue berries and are perennial...

, where it acts as an antimicrobial agent.
Methylparaben is an anti-fungal agent often used in a variety of cosmetics and personal-care products.