173918-07-5

Upstream product

• 173918-06-4 L-O-leucine-D-alanine benzyl ester 
• 20312-37-2 (R)-2-hydroxy-4-methylpentanoic acid 
• 41036-32-2 D-alanine benzyl ester p-toluenesulphonate salt 
• 1189526-10-0 L-OTBDMS-valine-L-valine benzyl ester 
• 2462-34-2 L-valine benzyl ester hydrochloride 
• 17407-55-5 (S)-2-Hydroxy-3-methylbutanoic acid 

Downstream Products

• 173918-12-2 L-O-valine-L-valine-D-O-leucine-D-alanine benzyl ester 
• 173918-09-7 L-O-valine-L-valine-D-O-leucine-D-alanine-L-O-valine-L-valine-D-O-leucine-D-alanine benzyl ester 
• 1189526-11-1 L-OTBDMS-valine-L-valine-D-O-leucine-D-alanine-L-O-valine-L-valine-D-O-leucine-D-alanine-L-O-valine-D-O-leucine-D-alanine benzyl ester 

Relevant academic research and scientific papers

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)3 using LC-TOFMS. Quantitative analysis of cereulide in the broth revealed production of cereulide in the stationary phase and decomposition in the death phase. The increase in tetradepsipeptide continued after the stationary phase until decomposition occurred.

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. Homocereulide is a cyclic dodecadepsipeptide composed of L-O-Val-L-Val-D-O-Leu-D-Ala and L-O-allo-Ile-D-Val-D-O-Leu-D-Ala. Here, we synthesized homocereulide using liquid phase fragment condensation. The NMR spectrum of synthesized homocereulide confirmed the intended structure and LC-MS results were consistent with natural products. Morphological evaluation using HEp-2 cells showed higher toxicity with homocereulide (1.39 nM) than cereulide (3.95 nM). Though cereulide is the main component in broth culture, homocereulide is also likely involved in B. cereus-associated food poisoning.

Synthesis of four lysine-linked cereulide analogues showing ionophoric activity towards potassium cations as lead compounds for emetic toxin-detection by immunoassays

An improved total synthesis of the emetic toxin cereulide and the preparation of four lysine-linked cereulide analogues is described. The cereulide analogues are prepared by replacing one of the amino acid residues in cereulide with lysine. The cereulide analogues demonstrate ionophoric activity towards alkali metal ions and inorganic ammonium ions, and are currently being used to develop an enzyme-linked immunosorbent assay for cereulide. Georg Thieme Verlag Stuttgart.