Question

Propose a structure for an octapeptide (contains 8 amino acids) that shows the following composition on amino acid analysis: Asp, Gly2, Leu, Phen, Pro2, Val. Edman analysis shows a glycine N-terminal group, and leucine is the C-terminal group. Acidic hydrolysis gives the following fragments: Val-Pro-Leu, Gly, Gly-Asp-Phe-Pro, Phe-Pro-Val (ii) Propose a solution-phase synthesis for the Val-Pro-Leu fragment in (i). Include reagents, intermediates and protection/deprotection steps in your answer (note: reaction mechanisms are not required).

Answer 1

It includes four steps to the creation of the structure of the octapeptide using 8 amino acids with the amino acid analysis. In the first step, there are four alpha-amino acid structures including the aromatic rings of Phenylaninine, Tyrosine, Histidine, and tryptophan. In the second step, two amino acid chains Cysteine and Methionine are formed containing sulphur. In step 3, amino acids containing Serinine and Theronine are formed containing alcohol compounds.In step 5, five hydrocarbon compounds are formed.