T. Motoyama, S. Nakano, F. Hasebe
Jul 16, 2021
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0
Influential Citations
2
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Journal
Communications Chemistry
Abstract
Pyrazines are typically formed from amino acids and sugars in chemical reactions such as the Maillard reaction. In this study, we demonstrate that 3-ethyl-2,5-dimethylpyrazine can be produced from L-Thr by a simple bacterial operon. We conclude that EDMP is synthesized chemoenzymatically from L-Thr via the condensation reaction of two molecules of aminoacetone and one molecule of acetaldehyde. Aminoacetone is supplied by L-threonine 3-dehydrogenase using L-Thr as a substrate via 2-amino-3-ketobutyrate. Acetaldehyde is supplied by 2-amino-3-ketobutyrate CoA ligase bearing threonine aldolase activity from L-Thr when CoA was at low concentrations. Considering the rate of EDMP production, the reaction intermediate is stable for a certain time, and moderate reaction temperature is important for the synthesis of EDMP. When the precursor was supplied from L-Thr by these enzymes, the yield of EDMP was increased up to 20.2%. Furthermore, we demonstrate that this reaction is useful for synthesizing various alkylpyrazines. Threonine is a biosynthetic precursor to dimethylpyrazine derivatives, but the pathway by which this occurs is not fully established. Here l -throenine-3-dehydrogenase and 2-amino-3-ketobutyrate CoA ligase together are shown to convert l -threonine to dimethylpyrazine derivatives as a byproduct of glycine metabolism.