Inhibition of porcine liver carboxylesterase by phosphorylated flavonoids
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- 作者：Yingling Wei ; Ai-Yun Peng ; cespay@mail.sysu.edu.cn ; Jiale Huang
- 关键词：CE ; carboxylesterase ; CEase ; cholesterol esterase ; AChE ; acetylcholinesterase ; pNPB ; p-nitrophenyl butyrate ; IC50 ; the half maximal inhibitory concentration
- 刊名：Chemico-Biological Interactions
- 出版年：2013
- 出版时间：5 July, 2013
- 年：2013
- 卷：204
- 期：2
- 页码：75-79
- 全文大小：1039 K
文摘
We have recently synthesized a series of phosphorylated flavonoids and identified some of them as potent inhibitors of pancreatic cholesterol esterase (CEase) with excellent selectivity for CEase over acetylcholinesterase (AChE). In the present paper, we investigated the inhibitory activities of these compounds against porcine liver carboxylesterase (CE) since carboxylesterases (CEs) are another family of serine esterases responsible for the metabolism and detoxification of many ester-containing xenobiotics and clinical esterified drugs, and there exists much structural similarity between CEase and CEs. The results indicated that phosphorylated flavonoids exhibited significantly improved inhibition potency toward CE than their parent compounds, and six of them had IC50 values less than 5.0 nM. Among all compounds tested, compounds class=""boldFont"">3d and class=""boldFont"">3e are the two most potent inhibitors of CE, giving IC50 values of 1.79 nM and 1.58 nM, respectively. Interestingly, these compounds inhibited CEase and CE with similar structure activity correlations, and those with high inhibitory activities toward CEase could also inhibit CE efficiently. The presences of a free hydroxyl group at position 5 and a phosphate group at position 7 of the phosphorylated flavonoids are favorable to the inhibition of CE. The inhibition mechanism and kinetic characterization studies of the most potent inhibitors revealed that they are irreversible competitive inhibitors.