College of Food Science and Engineering, South China University of Technology, Wushan Road 381, Guangzhou, Guangdong, 510640, China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Wushan Road 381, Guangzhou, Guangdong, 510640, China.
J Biotechnol. 2021 Aug 20;337:46-56. doi: 10.1016/j.jbiotec.2021.06.023. Epub 2021 Jun 29.
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, esculin-6'-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.
秦皮素是一种具有多种生物活性和低亲脂性的多酚。因此，开发了一种秦皮素酰化的全细胞催化策略，以提高其亲脂性。共测试了 12 株菌株，其中施氏假单胞菌表现出最高的催化活性和单酰化区域选择性。在最佳条件下，当醋酸乙烯酯作为酰基供体时，24 小时内转化率达到了 92.7%的最高水平。P. stutzeri 的催化能力在三个循环后仍保持在 60%以上。随后，合成并结构鉴定了五种具有不同脂肪酸链长度的秦皮素酯。其中，秦皮素-6'-O-辛酸酯、秦皮素-6'-O-月桂酸酯和秦皮素-6'-O-肉豆蔻酸酯通过诱导细胞凋亡和坏死对 LO2 细胞表现出细胞毒性。这三种酯的细胞毒性可能归因于它们的膜破坏特性。本研究为秦皮素的酰化提供了一种新的全细胞生物催化策略，并为秦皮素酯作为食品添加剂或药物的应用提供了新的思路。
