Interpretation:
The product(s) of each of the given reactions are to be determined.
Concept Introduction:
Hydrolysis of a peptide with a
Treatment of a peptide with phenyl isothiocyanate protects the N terminus of the chain. Subsequent treatment with a strong acid in anhydrous conditions cleaves only the amide bond between the protected amino acid residue and the rest of the peptide chain.
Benzyloxycarbonyl chloride is used to protect the
Hydrogenolysis with hydrogen over palladium is used for deprotection of N terminus.
Want to see the full answer?
Check out a sample textbook solutionChapter 26 Solutions
Organic Chemistry - Standalone book
- The dynorphins are a group of opioid peptides that play an importantrole in changes in the brain associated with cocaine addiction. One ofthese peptides, dynorphin A, contains the following amino acidsequence: Tyr–Gly–Gly–Phe–Leu–Arg–Arg–Ile–Arg–Pro–Lys–Leu–Lys.Draw the amino acids and peptide fragments formed when dynorphin A is treated with each reagent or enzyme: (a) chymotrypsin; (b) trypsin; (c)carboxypeptidase; (d) C6H5N=C=S.arrow_forwardCompounds with polyfunctional groups must follow priority rule. Which of the following compound is correctly named. Justify your claim and construct its correct structure. А: 3-amino-7-carboxy-4-oxoheptanamide 3-amino-7-carbanoyl-4-oxoheptanoic acid 3-amino-4-ox0-7-carbanoylheptanoic acid 3-amino-4-oxo-7-carboxyheptanamide В: С: D:arrow_forwardB Identify the functional groups found in the side chair (the & group). Is the R-group. polar neutral polar changed, or non-polar & №t₂ CH₂ ANCH E-0- Aspamagine CH3 Ś CH₂ ₂ O + HƠN CH Co Methionine HO HD Cf chts - c-E-0- threonne If these o acids represent L-amino acids, draw the general structure for a D-amino acid.arrow_forward
- Suggest a scheme you will follow to synthesise the dipeptide Ala-Glyarrow_forwardHistamine is synthesized from one of the 20 protein-derived amino acids. Suggest which amino acid is its biochemical precursor and the type of organic reaction(s) involved in its biosynthesis (e.g., oxidation, reduction, decarboxylation, nucleophilic substitution). CH,CH,NH, H. Histaminearrow_forwardShow how you would synthesize any of the standard amino acids from each starting material. You may use any necessaryreagents.O(CH3)2CH C COOH(a)CH2CH3(b) CH3 CH CH2 COOH (c) (CH3)2 CH¬CH2¬CHOarrow_forward
- Write a structural formula for the product formed by treatment of the N-terminal amino group with Sanger’s reagent and propose a mechanism for its formation.arrow_forwardUsing the information below, determine the amino acid sequence of the peptide, and explain how your structure is consistent with each piece of information. Complete hydrolysis by 6 M HCl at 110°C followed by amino acid analysis indicated the presence of Gly, Leu, Phe, and Tyr in a 2:1:1:1 molar ratio. Treatment of the peptide with1-fluoro-2,4-dinitrobenzene followed by complete hydrolysis and chromatography indicated the presence of the 2,4-dinitrophenyl derivative of tyrosine. No free tyrosine could be found. Complete digestion of he peptide with pepsin (which cleaves on the amino side of aromatic residues) followed by chromatography yielded a dipeptide containing Phe and Leu and a tripeptide containing Tyr and Gly in a 1:2 ratio.arrow_forward(a) Predict the product of the reaction of KOH with 1-amino propane. (b) Predict the product of a deprotonated ethanol (an “ethanolate anion", O-CH2-CH3) with phenol (hydroxybenzene). (c) Predict the product of propanoic acid with deprotonated ethanol (an “ethanolate anion", O-CH2-CH3).arrow_forward
- An octapeptide contains the following amino acids: Arg, Glu, His, Ile, Leu, Phe, Tyr, and Val. Carboxypeptidase treatment of the octapeptide forms Phe and a heptapeptide. Treatment of the octapeptide with chymotrypsin forms two tetrapeptides, A and B. Treatment of A with trypsin yields two dipeptides, C and D. Edman degradation cleaves the following amino acids from each peptide: Glu (octapeptide), Glu (A), Ile (B), Glu (C), and Val (D). Partial hydrolysis of tetrapeptide B forms Ile–Leu in addition to other products. Deduce the structure of the octapeptide and fragments A–D.arrow_forwardGlycine is a diprotic acid, which can potentially undergo two dissociation reactions, one for the a-amino group (-NH3), and the other for the carboxyl (-COOH) group. Therefore, it has two pKą values. The carboxyl group has a pK₁ of 2.34 and the a-amino group has a pK₂ of 9.60. Glycine can exist in fully deprotonated (NH₂-CH₂-COO-), fully protonated (NH3-CH₂-COOH), or zwitterionic form (NH3-CH₂-COO-). Match the pH values with the corresponding form of glycine that would be present in the highest concentration in a solution of th pH. fully deprotonated form NH,−CH,−COO- pH 11.9 pH 6.0 pH 8.0 fully protonated form NH3-CH₂-COOH pH 1.0 Answer Bank pH 7.0 zwitterionic form NH3-CH₂-COO-arrow_forwardAn amino acid mixture of phenylalanine, glycine and glutamic acid is to be separated bypaper chromatography. The solvent is less polar than water. Which of these amino acids will have the highest Rf value and which the lowest? Explain. Treatment of a new protein with dansyl chloride reveals two (2) dansyl-labelled derivatives of amino acids, alanine and methionine. What can you deduce about the structure of the protein from these results? Name the amino acids that contribute atoms to both purine and pyrimidine rings.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning