Analysis of species-dependent hydrolysis and protein binding of esmolol enantiomers  

作　　者：Yi-Hong Tanga,b,1,Jun-Yan Wanga,1,Hai-Hong Hua,Tong-Wei Yaoa,Su Zenga,n aDepartment of Pharmaceutical Analysis and Drug Metabolism,College of Pharmaceutical Sciences,Zhejiang University,Hangzhou,Zhejiang 310058,People’s Republic of China bShanghai Institute of Technology,Shanghai 201418,People’s Republic of China 

出　　处：《Journal of Pharmaceutical Analysis》2012年第3期220-225,共6页药物分析学报（英文版）

基　　金：supported by National Major Projects of Ministry Science and Technology of China(2011CB710800,2012ZX09506001-004);Zhejiang Education Department(Y200909571)

摘　　要：The stereoselective hydrolysis of esmolol in whole blood and in its separated components from rat,rabbit and human was investigated.Blood esterase activities were variable in different species in the order of rat>rabbit>human.Rat plasma showed the high esterase activity and had no stereoselectivity to enantiomers.Rabbit red blood cell（RBC） membrane,RBC cytosol and plasma all hydrolyzed esmolol but with different esterase activity,whereas the hydrolysis in RBC membrane and cytosol showed significant stereoselectivity towards R-（+）-esmolol.Esterase in RBC cytosol from human blood mainly contributed to the esmolol hydrolysis,which was demonstrated with no stereoselctivity.Esterase in human plasma showed a low activity,but a remarkable stereoselectivity with R-（+）-esmolol.In addition,the protein concentration affected the hydrolysis behavior of esmolol in RBC suspension.Protein binding of esmolol enantiomers in human plasma,human serum albumin（HSA） and α;-acid glycoprotein（AGP） revealed that there was a significant difference in bound fractions between two enantiomers,especially for AGP.Our results indicated that the stereoselective protein binding might play a role in the different hydrolysis rates of esmolol enantiomers in human plasma.The stereoselective hydrolysis of esmolol in whole blood and in its separated components from rat,rabbit and human was investigated.Blood esterase activities were variable in different species in the order of rat>rabbit>human.Rat plasma showed the high esterase activity and had no stereoselectivity to enantiomers.Rabbit red blood cell(RBC) membrane,RBC cytosol and plasma all hydrolyzed esmolol but with different esterase activity,whereas the hydrolysis in RBC membrane and cytosol showed significant stereoselectivity towards R-(+)-esmolol.Esterase in RBC cytosol from human blood mainly contributed to the esmolol hydrolysis,which was demonstrated with no stereoselctivity.Esterase in human plasma showed a low activity,but a remarkable stereoselectivity with R-(+)-esmolol.In addition,the protein concentration affected the hydrolysis behavior of esmolol in RBC suspension.Protein binding of esmolol enantiomers in human plasma,human serum albumin(HSA) and α_1-acid glycoprotein(AGP) revealed that there was a significant difference in bound fractions between two enantiomers,especially for AGP.Our results indicated that the stereoselective protein binding might play a role in the different hydrolysis rates of esmolol enantiomers in human plasma.

关 键 词：Esmolol enantiomers Species-dependent Stereoselective hydrolysis Protein binding 

分 类 号：R914[医药卫生—药物化学]