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Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
Benzalacetone synthase
Yoshihiko Shimokawa1, Hiroyuki Morita, Ikuro Abe
1Graduate School of Pharmaceutical Sciences, The University of Tokyo Bunkyo-ku, Tokyo, Japan.
Frontiers in Plant Science
|May 31, 2012
Summary
This study reveals how benzalacetone synthase (RpBAS) from Rheum palmatum produces benzalacetone. Structural insights explain its unique diketide formation and catalytic mechanisms, enabling novel polyketide scaffold generation.
Area of Science:
- Biochemistry
- Structural Biology
- Enzymology
Background:
- Benzalacetone synthase (RpBAS) belongs to the chalcone synthase (CHS) superfamily, a type III polyketide synthase (PKS).
- RpBAS is crucial for synthesizing the benzalacetone scaffold from 4-coumaroyl-CoA and malonyl-CoA.
Purpose of the Study:
- To elucidate the structural basis of RpBAS's catalytic activity and substrate specificity.
- To investigate the novel catalytic machinery involved in benzalacetone formation.
- To explore the potential of RpBAS in generating unnatural polyketide scaffolds.
Main Methods:
- X-ray crystallography of RpBAS.
- Enzyme kinetics and activity assays.
- Precursor-directed biosynthesis.
Main Results:
- RpBAS's diketide formation is linked to a Phe-to-Leu substitution in the active site.
- Crystal structures revealed unique mechanisms for thioester bond cleavage and decarboxylation.
- RpBAS demonstrated remarkable substrate tolerance, enabling the synthesis of diverse unnatural polyketide scaffolds.
Conclusions:
- Structural findings provide a basis for understanding the functional diversity within type III PKS enzymes.
- RpBAS serves as a versatile tool for generating novel polyketide structures.
- The study highlights the potential of medicinal plants in discovering novel enzymatic pathways.
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