Chemoenzymatic Synthesis and Biological Evaluation of (−)‐Conduramine C‐4

Abstract

Previously unreported (−)‐conduramine C‐4 was synthesized in six steps from a bacterial bromobenzene metabolite in 23% overall yield. The chemoenzymatic route involved toluene dioxygenase dihydroxylation, β‐epoxidation, epoxide ring‐opening, Staudinger reduction, radical debromination, and Amberlite‐ catalyzed hydrolysis. (−)‐Conduramine C‐4 and other related compounds synthesised were assayed for galactosidase‐activity inhibition against β‐D‐galactoside galactohidrolase isolated from Aspergillus oryzae.

Keywords:

• chemoenzymatic
• conduramine
• glycosidase inhibitors
• toluene dioxygenase

Acknowledgment

The authors are grateful to IFS (Grants F/3078‐1 and F/3078‐2) and CONICYT (FCE 8068) for financial support of this work. A. B. is grateful to PEDECIBA and DINACYT for a doctoral fellowship. The authors acknowledge Jorge Adum for carrying out the fermentation process and Horacio Pezzaroglo for recording nuclear magnetic resonance (NMR) spectra.