claim: The capitol city of Catalonia is Barcelona.
evidence: N-Acetylcarnosine -LRB- NAC -RRB- is a naturally occurring compound chemically related to the dipeptide carnosine .. compound. Chemical compound. carnosine. carnosine. The NAC molecular structure is identical to carnosine with the exception that it carries an additional acetyl group .. carnosine. carnosine. acetyl. acetyl. The acetylation makes NAC more resistant to degradation by carnosinase , an enzyme that breaks down carnosine to its constituent amino acids , beta-alanine and histidine .. carnosine. carnosine. carnosinase. carnosinase. enzyme. enzyme. beta-alanine. beta-Alanine. histidine. histidine