Reconsidering the Structure of Serlyticin-A

Area of Science:

• Natural Product Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Serlyticin-A, a metabolite from *Serratia ureilytica*, exhibits antioxidant and antiproliferative properties.
• The previously proposed chemical structure of serlyticin-A contains unstable heteroatom-heteroatom bonds, suggesting an error.

Purpose of the Study:

• To revise the incorrect chemical structure of serlyticin-A using computational methods.
• To identify the correct structure of serlyticin-A and confirm its properties.

Main Methods:

• Quantum chemical calculations were employed to predict 1H and 13C NMR chemical shifts.
• Calculated NMR shifts were compared against experimental data to identify structural discrepancies.
• De novo synthesis was performed to obtain pure 3-indolylacetohydroxamic acid for experimental validation.

Main Results:

• A significant discrepancy was observed between calculated and experimental NMR chemical shifts for the proposed serlyticin-A structure.
• Computational analysis suggested several plausible alternative structures.
• 3-indolylacetohydroxamic acid was identified as the most likely correct structure based on stability, activity, and NMR data.

Conclusions:

• Computational NMR shift prediction is a powerful tool for revising natural product structures.
• Serlyticin-A is likely 3-indolylacetohydroxamic acid, a stable and biologically active natural product.
• This revised structure aligns with the known properties of hydroxamic acids found in bacterial metabolites.