The present disclosure generally relates to the production of natural vanillin by biocouversion using isoeugenol as the substrate. More specifically, the present methods utilize a filitgal isoeugenol monooxygenase to catalyze the bioconversion of isoeugenol to vanillin, which can be carried out in a cellular system (e.g., bacteria or yeasts) or in an enzymatic reaction mixture without a cellular system.