14456
Nucleotide oligomerization domain - containing protein 2 ( Nod2 ) , an innate immune receptor , recognizes bacterial cell - wall peptidoglycan ( PGN ) , the minimum ligand of which is muramyl dipeptide ( MDP ) .
 Chemical: Nucleotide; Chemical: muramyl dipeptide; Chemical: MDP
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: Nucleotide, muramyl dipeptide, MDP 
Answer:
 Chemical: Nucleotide; Chemical: muramyl dipeptide; Chemical: MDP