Related Experiment Video
Updated: May 23, 2026
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
6-Deoxyerythronolide B synthase thioesterase-catalyzed macrocyclization is highly stereoselective
Atahualpa Pinto1, Meng Wang, Mark Horsman
1Department of Chemistry, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada T1N 6N5.
The study demonstrates that the erythromycin polyketide synthase thioesterase (DEBS TE) precisely controls macrocyclization. This enzyme exhibits high stereospecificity and regioselectivity, crucial for synthesizing therapeutic polyketide natural products.
Area of Science:
- Biochemistry
- Organic Chemistry
- Natural Product Synthesis
Background:
- Macrocyclic polyketides are vital therapeutic agents.
- Their biosynthesis involves regio- and stereoselective macrocyclization by thioesterases.
- Understanding thioesterase specificity is key to drug development.
Purpose of the Study:
- To investigate the substrate specificity of the erythromycin polyketide synthase thioesterase (DEBS TE).
- To elucidate the regio- and stereoselectivity of the macrocyclization reaction catalyzed by DEBS TE.
Main Methods:
- Synthesis of a panel of substrate molecules.
- In vitro enzymatic assays using purified DEBS TE.
- Analysis of reaction products to determine stereochemistry and regiochemistry.
Main Results:
- DEBS TE demonstrated high stereospecificity, favoring substrates with an R-configured O-nucleophile for macrocyclization.
- The enzyme exhibited high regioselectivity, exclusively forming a 14-member lactone over a potential 12-member lactone.
- Successful macrocyclization of a 14-member ring substrate was confirmed.
Conclusions:
- DEBS TE possesses remarkable stereo- and regioselectivity in catalyzing macrocyclization.
- This specificity is critical for the precise biosynthesis of polyketide natural products.
- Findings provide insights into the mechanism of thioesterases and potential for synthetic biology applications.
More Related Videos
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
11:04Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Related Concept Videos
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Thermal and Photochemical Electrocyclic Reactions: Overview
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Intramolecular Claisen Condensation of Dicarboxylic Esters: Dieckmann Cyclization