8968
Systematic theoretical searches have been carried out to identify the most stable conformers of both the homo - and heterochiral protonated serine dimer and octamer .
 Chemical: serine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: serine 
Answer:
 Chemical: serine