Login Registrieren

Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Chapter 24: Q14P (page 1272)

Question: Propose a mechanism for the acid-catalyzed hydrolysis of phenylalanine ethyl ester.

Short Answer

Expert verified

Step by step solution

01

Step-by-Step solutionStep 1: Esterification of carboxyl group

Esters of amino acids can be used as protected derivatives in order to prevent the carboxyl group from reacting in an unusual manner. The most common protecting groups are methyl, ethyl and benzyl estersA

02

Mechanism

Ester is hydrolyzed by the aqueous acid which regenerates the free amino acid.

Mechanism for acid-catalyzed hydrolysis of phenylalanine ethyl ester to phenylalanine

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Draw the complete structures of the following peptides:

(a) Thr-Phe-Met (b) Serylarginylglycylphenylalanine (c) IMQDK (d) ELVIS

The following structure is drawn in an unconventional manner.

(a) Label the N terminus and the C terminus.

(b) Label the peptide bonds.

(c) Identify and label each amino acid present.

(d) Give the full name and the abbreviated name

A molecular weight determination has shown that an unknown peptide is a pentapeptide, and an amino acid analysis shows that it contains the following residues: one Gly, two Ala, one Met, one Phe. Treatment of the original pentapeptide with carboxypeptidase gives alanine as the first free amino acid released. Sequential treatment of the pentapeptide with phenyl isothiocyanate followed by mild hydrolysis gives the following derivatives:

Propose a structure for the unknown pentapeptide.

The Sanger method for N-terminus determination is a less common alternative to the Edman degradation. In the Sanger method, the peptide is treated with the Sanger reagent, 2,4-dinitrofluorobenzene, and then hydrolyzed by reaction with 6 M aqueous HCl. The N-terminal amino acid is recovered as its 2,4-dinitrophenyl derivative and identified.

(a)Propose a mechanism for the reaction of the N terminus of the peptide with 2,4-dinitrofluorobenzene.

(b) Explain why the Edman degradation is usually preferred over the Sanger method.

Complete hydrolysis of an unknown basic decapeptide gives Gly, Ala, Leu, Ile, Phe, Tyr, Glu, Arg, Lys, and Ser. Terminal residue analysis shows that the N terminus is Ala, and the C terminus is Ile. Incubation of the decapeptide with chymotrypsin gives two tripeptides, A and B, and a tetrapeptide, C. Amino acid analysis shows that peptide A contains Gly, Glu, Tyr, and; peptide B contains Ala, Phe, and Lys; and peptide C contains Leu, Ile, Ser, and Arg.Terminal residue analysis gives the following results.

Incubation of the decapeptide with trypsin gives a dipeptide D, a pentapeptide E, and a tripeptide F. Terminal residue analysis of F shows that the N terminus is Ser and the C terminus is Ile. Propose a structure for the decapeptide and for fragments A through F.

See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Chemical Reactions

Read Explanation

Kinetics

Read Explanation

The Earths Atmosphere

Read Explanation

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free