12604
Four new metabolites M - 1 [ 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan ] , M - 2 [ 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan ] , M - 3 [ 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 4 - formaldehyde - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan ] , and M - 4 [ 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 4 - oxy - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan ] were isolated from the chloroform extract of koumine incubated with phenobarbital - treated rat liver microsomes .
 Chemical: 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 4 - formaldehyde - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 4 - oxy - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: chloroform; Chemical: koumine; Chemical: phenobarbital
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 18 , 19 - tetradehydro - 4 - demethyl - 4 - formaldehyde - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: 1 , 2 , 4 , 21 , 18 , 19 - hexadehydro - 4 - demethyl - 4 - oxy - 3 , 17 - epoxy - 7 , 20 ( 2H , 19H ) - cyclovobasan; Chemical: chloroform; Chemical: koumine; Chemical: phenobarbital