ArticleNature chemical biology2026
Enzymatic epimerization of monoterpene indole alkaloids in kratom.
Article in Nature chemical biology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
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11 citing papers in PubMed.
- A review on Mitragyna alkaloids pharmacology, biosynthesis and biotechnological insights.Journal, genetic engineering & biotechnology · 2026Review
- Discovery of a Plant Pictet-Spenglerase With R-Stereoselectivity.Angewandte Chemie (International ed. in English) · 2026Article
- Biosynthesis of cinchona alkaloids.Nature · 2026Article
- Identification and Optimization of Kratom Strictosidine Pathway Enabled by Yeast Multiplex Engineering.bioRxiv : the preprint server for biology · 2026Article
- Construction of the Pentacyclic Core of Yohimbine Alkaloids: A Chemoenzymatic Approach.Chemistry, an Asian journal · 2026Article
- Comparative analysis of monoterpene indole alkaloid composition and genotypic variation in ThaiFrontiers in plant science · 2026Article
- Four enzymes from button bush enable de novo biosynthesis of spirooxindole alkaloids in yeast.Biodesign research · 2025Article
- Ancient gene clusters govern the initiation of monoterpenoid indole alkaloid biosynthesis and C3 stereochemistry inversion.Nature communications · 2025Article
- Ipecac alkaloid biosynthesis in two evolutionarily distant plants.Nature chemical biology · 2025Article
- A chromosome-level Mitragyna parvifolia genome unveils spirooxindole alkaloid diversification and mitraphylline biosynthesis.The Plant cell · 2025Article
- A Tight-Knit Family: The Medium-Chain Dehydrogenase/Reductases of Monoterpene Indole Alkaloid Biosynthesis.Biochemistry · 2025Review
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Abstract
Monoterpene indole alkaloids (MIAs) are a large, structurally diverse class of bioactive natural products. These compounds are biosynthetically derived from a stereoselective Pictet-Spengler condensation that generates a tetrahydro-β-carboline scaffold characterized by a 3S stereocenter. However, a subset of MIAs contains a noncanonical 3R stereocenter. Here we report the basis for 3R-MIA biosynthesis in Mitragyna speciosa (kratom). We discover the presence of the iminium species (20S)-3-dehydrocorynantheidine, which supports isomerization of 3S to 3R via oxidation and stereoselective reduction downstream of the initial Pictet-Spengler condensation. Isotopologue feeding experiments identify the sites for downstream MIA pathway biosynthesis as well as the oxidase/reductase pair that catalyzes this epimerization. This oxidase/reductase pair has broad substrate specificity, suggesting that this pathway may be responsible for the formation of many 3R-MIAs and downstream spirooxindole alkaloids in kratom. The elucidation of this epimerization mechanism allows biocatalytic access to a range of pharmacologically active spirooxindole alkaloid compounds.
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