Aspartame is the methyl ester of a dipeptide formed from aspartic acid and phenylalanine. It is about 100 times sweeter than cane sugar. However, it readily hydrolyzes and decomposes at elevated temperatures (cooking temperatures), thereby losing its sweetness. Consequently, its application is strictly restricted to cold foods and soft drinks.

Aspartame is a methyl ester dipeptide formed from aspartic acid and phenylalanine. It is unstable at cooking temperatures because it decomposes when heated. Therefore, its use is strictly limited to cold foods and soft drinks. In contrast, saccharin, sucralose, and alitame are thermally stable at cooking temperatures.

Analysis of medicinal chemistry statements:

• Analgesics relieve pain without major disruption of the nervous system or consciousness $\rightarrow$ Statement A is correct.
• Tranquilizers are neurologically active drugs that affect message transfer from nerve to receptor $\rightarrow$ Statement B is false.
• Morphine and its derivatives are narcotic analgesics which induce sleep and addiction in high doses $\rightarrow$ Statement C is false.
• Antiseptics are applied to living tissues (wounds, cuts), while disinfectants are applied to inanimate objects (floors, instruments) $\rightarrow$ Statement D is correct.
• For example, a $0.2\%$ solution of phenol is an antiseptic, while a $1\%$ solution of phenol acts as a disinfectant $\rightarrow$ Statement E is correct.