1) Amino acid 
Dehydroalanine (or (alpha)-(beta)-di-dehydroalanine) is an uncommon unsaturated amino acid found in peptides of microbial origin. Dehydroalanine (DHA) is also found in food proteins, including casein, that have been heated and/or treated with an alkali such as sodium hydroxide (NaOH). These treatments can dehydrate serine in the protein chain. In ...