<Li> O = C (O (C@H) 1C (C@H) 2N (C) (C @ @ H) ((C@H) 1C (= O) OCC) CC2) c3ccccc3 </Li> <P> Cocaethylene (ethylbenzoylecgonine) is the ethyl ester of benzoylecgonine . It is structurally similar to cocaine, which is the methyl ester of benzoylecgonine . Cocaethylene is formed by the liver when cocaine and ethanol coexist in the blood . </P> <P> Cocaethylene is the byproduct of concurrent consumption of alcohol and cocaine as metabolized by the liver . Normally, metabolism of cocaine produces two primarily biologically inactive metabolites--benzoylecgonine and ecgonine methyl ester . The hepatic enzyme carboxylesterase is an important part of cocaine's metabolism because it acts as a catalyst for the hydrolysis of cocaine in the liver, which produces these inactive metabolites . If ethanol is present during the metabolism of cocaine, a portion of the cocaine undergoes transesterification with ethanol, rather than undergoing hydrolysis with water, which results in the production of cocaethylene . </P> <Dl> <Dd> cocaine + H O → benzoylecgonine + methanol (with liver carboxylesterase 1) </Dd> <Dd> benzoylecgonine + ethanol → cocaethylene + H O </Dd> <Dd> cocaine + ethanol → cocaethylene + methanol (with liver carboxylesterase 1) </Dd> </Dl>

Cocaethylene is produced as an active metabolite of