Problem 85 - Chemistry An Atoms First Approach

Question

Aspartame, the artificial sweetener marketed under the name NutraSweet, is a methyl ester of a dipeptide: a. What two amino acids are used to prepare aspartame? b. There is concern that methanol may be produced by the decomposition of aspartame. From what portion of the molecule can methanol be produced? Write an equation for this reaction.

Step-by-Step Solution

Answer

a. The two amino acids used to prepare aspartame are Aspartic acid (\( C_4H_7NO_4 \)) and Phenylalanine (\( C_9H_{11}NO_2 \)). b. Methanol can be produced from the methoxy group (CH3O-) present in the methyl ester of aspartame. The equation for this reaction is: \( C_{14}H_{18}N_2O_5 + H_2O \rightarrow C_4H_7NO_4 + C_9H_{11}NO_2 + CH_4O \).

Step 1: Identifying the amino acids in aspartame

Aspartame is a dipeptide, which means it is formed by the combination of two amino acids. The structure of aspartame is given by the formula: \( C_{14}H_{18}N_2O_5 \) According to the structure, the two amino acids that are used to prepare aspartame are: 1. Aspartic acid (\( C_4H_7NO_4 \)) 2. Phenylalanine (\( C_9H_{11}NO_2 \)) Aspartame's systematic name is: N-L-α-aspartyl-L-phenylalanine 1-methyl ester.

Step 2: Identifying methanol production

Aspartame is a methyl ester, which means it has a methoxy group (CH3O-) bonded to an ester group in its structure. When aspartame decomposes, methanol can be liberated from this methoxy group, as it has the potential to undergo hydrolysis reaction.

Step 3: Writing the equation for methanol production

Since methanol is produced during the decomposition of aspartame, we can write the equation for this process. Upon hydrolysis, the methyl ester of aspartame breaks down to form aspartic acid, phenylalanine, and methanol. The equation for this reaction can be written as follows: \( C_{14}H_{18}N_2O_5 + H_2O \rightarrow C_4H_7NO_4 + C_9H_{11}NO_2 + CH_4O \) This equation represents the decomposition of aspartame in the presence of water, resulting in the production of aspartic acid, phenylalanine, and methanol.