Biosynthetic Pathways of Taxane Compounds

Taxane compounds are diterpenoid natural products predominantly synthesised in Taxus species via the methylerythritol phosphate and mevalonate pathways. These routes converge on geranylgeranyl diphosphate, which is cyclised by taxadiene synthase to taxa-4(5),11(12)-diene, the first committed intermediate. A series of regio- and stereospecific oxidations catalysed by cytochrome P450 monooxygenases, followed by acyltransferase-mediated esterifications, elaborate the taxane core through intermediates such as taxadien-5α-ol, 10-deacetylbaccatin III and baccatin III. The pathway’s complexity arises from enzyme promiscuity, subcellular compartmentalisation and low native yields. Advances in structural biology, gene network reconstitution and compartmentalised metabolic engineering have begun to clarify enzymatic specificities, by-product formation and metabolic flux control, paving the way for modular production platforms in plants and microbes.

Research from Nature Portfolio

Recent studies have structurally characterised taxadiene-5α-hydroxylase variants, uncovering multiple over-oxidation products that divert flux away from paclitaxel precursors. By fine-tuning promoter strength in a Nicotiana chassis, researchers reduced undesired by-product formation and achieved a three-fold increase in taxadien-5α-ol accumulation, enabling a six-step biosynthetic network to function coordinately. In a complementary approach, chloroplastic metabolic engineering in Nicotiana benthamiana, coupled with enhanced isoprenoid precursor pools, delivered taxadiene and taxadien-5α-ol titres exceeding 50 µg g⁻¹ fresh weight, demonstrating the feasibility of plant plastids as sustainable platforms for early taxane assembly.

Biosynthetic Pathways of Taxane Compounds publication trend

The graph below shows the total number of articles in biosynthetic pathways of taxane compounds across all publications each year (not limited to Nature Index journals).

Technical terms

Taxadiene: The cyclised diterpene core generated from geranylgeranyl diphosphate and the first committed intermediate in taxane biosynthesis.

Cytochrome P450: Haem-containing monooxygenases that introduce oxygen functionalities at specific positions of the taxane skeleton.

Heterologous host: A non-native organism engineered to express and study taxane pathway enzymes outside Taxus species.

Acyltransferase: Enzymes that catalyse the transfer of acyl groups, essential for esterifying hydroxylated taxane intermediates.

Metabolic flux: The rate at which substrates and intermediates flow through a biosynthetic pathway, crucial for optimising overall yield.

References

1. Reconstitution of early paclitaxel biosynthetic network. Nature Communications (2024).
2. Chloroplastic metabolic engineering coupled with isoprenoid pool enhancement for committed taxanes biosynthesis in Nicotiana benthamiana. Nature Communications (2019).
3. Comparative metabolomics reveals the metabolic variations between two endangered Taxus species (T. fuana and T. yunnanensis) in the Himalayas. BMC Plant Biology (2018).
4. Enhanced production of taxadiene in Saccharomyces cerevisiae. Microbial Cell Factories (2020).
5. Cyclization of Geranylgeranyl Diphosphate to Taxa-4(5),11(12)-diene Is the Committed Step of Taxol Biosynthesis in Pacific Yew *. Journal of Biological Chemistry (1995).