Highly efficient whole-cell biosynthesis and cytotoxicity of esculin esters

作者：Hao, Lisha; Zhang, Mengmeng; Li, Xiaofeng^*; Xin, Xuan^*; Lei, Faling; Lai, Xueneng; Zhao, Guanglei; Wu, Hui

来源：Journal of Biotechnology, 2021, 337: 46-56.

DOI：10.1016/j.jbiotec.2021.06.023

• Esculin
• Esters
• Whole-cell catalysis
• Acylation
• Cytotoxicity
• Membrane-disrupting property

Esculin is a polyphenol with multiple bioactivities and poor lipophilicity. Therefore, a whole-cell catalytic strategy for esculin acylation was developed to improve its lipophilicity. A total of 12 strains were tested, among which Pseudomonas stutzeri exhibited the highest catalytic activity and mono-acylated regioselectivity. The conversion reached the highest level of 92.7 % at 24 h under the optimal conditions, when vinyl acetate was used as an acyl donor. The catalytic ability of P. stutzeri remained above 60 % after three cycles. Subsequently, five esculin esters with different lengths of fatty chains were synthesized and structurally identified. Of them, esculin6 '-O-octanoate, esculin-6 '-O-laurate, and esculin-6 '-O-myristate exhibited cytotoxicity on LO2 cells by inducing apoptosis and necrosis. The cytotoxicity of these three esters may attribute to their membrane-disrupting properties. This study provides a novel whole-cell biocatalytic strategy for the acylation of esculin and insight for application of esculin esters as a food additive or drug.