Bacteria from foods and gut microbiota produce methylglyoxal and this metabolite leads to the formation of bioactive 1-acetyl-β-carboline alkaloids.

ABSTRACT: Methylglyoxal (MGO) is a highly reactive and toxic compound whereas 1-acetyl-β-carbolines (ACE-βCs) are bioactive alkaloids. These compounds were studied in cultures of bacteria from foods and human gut microbiota. Two ACE-βCs were identified as 1-acetyl-β-carboline (AβC) and 1-acetyl-β-carboline-3-carboxylic acid (AβC-COOH). Cultures containing ACE-βCs also contained MGO that was produced during bacterial growth. MGO produced by bacteria reacted spontaneously with L-tryptophan (L-Trp) and afforded ACE-βCs. MGO and ACE-βCs appeared in cultures from Escherichia coli and Lactilactobacillus sakei but not in cultures from other lactobacilli (L. plantarum, L. rhamnosus, and L. paracasei). Those bacteria producing MGO contained the enzyme methylglyoxal synthase (MgsA). MgsA was needed for the pr

SUBMITTER: Herraiz T 

PROVIDER: S-EPMC12873402 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature