Versatile 2-Oxoglutarate-Dependent Dioxygenases Catalyze Radical-Mediated Multifunctional Skeleton Reconstructions...

Taxane diterpenoids exhibit high scaffold diversity, with 6/8/6 and 5/7/6 frameworks being the most common. 5/7/6 taxoids, exemplified by taxuspine J, display promising pharmacological activities, but their chemical diversity and biosynthesis remain largely unexplored. Here, we characterized two novel 2-oxoglutarate-dependent dioxygenases, TcOGD1 and TcOGD2, which exhibit remarkable catalytic versatility, including skeleton reconstructions from 6/8/6 taxanes to 5/7/6, trinor-5/7/6, and 6/12 frameworks, and oxidation modifications at C-5, C-6, C-16, or C-20 of various taxoids. Specifically, they catalyze the skeletal rearrangement of 2-deacetoxytaxinine J (a 6/8/6 taxoid) and subsequent oxidation modifications to produce taxuspine J and a panel of 15,16,17-trinor-5/7/6 taxoids, which were identified through scale-up enzymatic reactions and NMR spectroscopy. Mechanistic investigation reveals a substrate-specific oxidative degradation for constructing the trinor-5/7/6 scaffold via radical-mediated C-C bond cleavage, accompanied by acetone release. In addition, TcOGD1 catalyzes two distinct transformations of a new Δ^5,6 containing 6/8/6 taxoid isolated from Taxus chinensis var. mairei, including C-C bond cleavage coupled with aldehyde formation to form a unique highly unsaturated 6/12 taxoid, and C-16 aldehyde formation to yield a 6/8/6 taxoid. TcOGD1 also mediates the 5-OH oxidation of a 6/10/6 taxoid. Furthermore, five novel trinor-5/7/6 taxoids were isolated from the Taxus plant, and taxuspine J and trinor-5/7/6 taxoids showed effective tumor resistance reversal activity. Our findings offered new insights into the formation of taxane structural diversity, expanded the chemical space of taxane diterpenoids, and provided valuable biocatalytic tools for constructing unusual taxane architectures through enzyme engineering or synthetic biology.