Acetovanillone, also known as apocynin, is an organic compound with the chemical formula C9H10O3. It is a derivative of vanillin, featuring a methoxy group and a hydroxyl group on the benzene ring, with an acetyl group at the para position relative to the hydroxyl group. It appears as a white to off-white crystalline powder. Its primary industrial application is as a fragrance ingredient and flavoring agent. It imparts sweet, vanilla-like, and slightly smoky notes, making it valuable in the formulation of perfumes, cosmetics, and food flavorings. Beyond its use in flavors and fragrances, acetovanillone is a recognized bioactive compound. It acts as a selective inhibitor of NADPH oxidase, an enzyme complex involved in generating reactive oxygen species, which has led to its extensive use as a pharmacological tool in biomedical research to study oxidative stress and inflammation pathways. Furthermore, due to its distinct phenolic and ketone functional groups, acetovanillone serves as a versatile synthetic building block in organic chemistry. It is used in the synthesis of more complex molecules, including pharmaceuticals and fine chemicals, through reactions such as condensations and further functional group transformations.