Chemical structure of hydrolysates of cereulide and their time course profile.

Hydrolysates of an emetic toxin cereulide were found in the broth of Bacillus cereus. The ester cleaved depsipeptides of cereulide were synthesized using liquid phase fragment condensation method starting from commercially available amino acids. The chemical structure of hydrolysates was verified tetradepsipeptide l-O-Val-l-Val-D-O-Leu-d-Ala and dodecadepsipeptide (D-O-Leu-d-Ala-l-O-Val-l-Val) using LC-TOFMS.

Synthesis of the reported structure of homocereulide and its vacuolation assay.

Homocereulide, isolated from marine bacterium Bacillus cereus, is an analog of emetic toxin cereulide. There is no report on its structure determination and involvement in B. cereus-associated food poisoning.