Demethylation is a chemical process widely distributed in nature to remove a methyl group from an organic molecule, which is a key aspect of diverse biological processes including biosynthesis of natural products, degradation of plant biomass and epigenetic regulation. This process is facilitated by diverse demethylases via distinct mechanisms. Recent studies have disclosed some novel demethylation reactions as well as their underlying demethylases in the biosynthesis of bacterial sterols, fungal terpenoids, and plant alkaloids. This article focuses on current advances in dissecting the demethylation reactions in biosynthesis of natural products and aims to point out the enzymatic mechanisms, which will further enhance our knowledge and understanding of demethylation process in nature.

去甲基化是一种广泛分布于自然界的化学过程，用于从有机分子中去除甲基，这是多种生物过程的关键方面，包括天然产物的生物合成、植物生物量的降解和表观遗传调控。这个过程是由不同的去甲基酶通过不同的机制促进的。最近的研究揭示了一些新的去甲基化反应及其在细菌甾醇、真菌萜类和植物生物碱的生物合成中的潜在去甲基化酶。本文侧重于剖析天然产物生物合成中去甲基化反应的最新进展，旨在指出酶促机制，这将进一步增进我们对自然界去甲基化过程的认识和理解。