18016
The first system starts with the methylation of nicotinamide by nicotinamide N - methyltransferase , which can subsequently be oxidized by aldehyde oxidase .
 Chemical: nicotinamide; Chemical: nicotinamide; Chemical: N; Chemical: aldehyde
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: nicotinamide; Chemical: nicotinamide; Chemical: N; Chemical: aldehyde