L-Asparagine tert-butyl ester hydrochloride is a protected form of L-Asparagine (A790005). L-Asparagine was first isolated by Robiquet and Vauquelin from asparagus juice (a high source of L-asparagine). L-Asparagine is often incorporated into proteins, and is a basis for some cancer therapies as certain cancerous cells require L-asparagine for growth.