Topic 4: Solid Phase Peptide Synthesis

What is the primary purpose of Merrifield solid phase synthesis in peptide chemistry?

• To increase the solubility of peptides

• To facilitate the sequential addition of amino acids

• To ensure amino acids do not epimerize

• To avoid the need for hazardous reagents

Which reagent(s) is(are) commonly used for the activation of carboxylic acids in peptide synthesis?

• Uronium compounds (HBTU)

• Carbodiimide (DIC)

• Thionyl chloride

• ATP

What is the role of uronium reagents in peptide synthesis?

• To protect amino acid side chains

• To deprotect the Fmoc group

• To activate carboxylic acids

• To neutralise acids

Which of the following is a common method for Fmoc deprotection in peptide synthesis?

• Treatment with trifluoroacetic acid

• Treatment with piperidine

• Treatment with hydrochloric acid

• Treatment with sodium hydroxide

What is the main advantage of using protecting groups for amino acid side chains in peptide synthesis?

• To increase the molecular weight of peptides

• To prevent unwanted side reactions

• To increase their solubility in organic solvents

• To decrease the solubility of peptides

Which of the following is a commonly used protecting group for the amino group in peptide synthesis?

• Boc (tert-butyloxycarbonyl)

• Acetyl

• Benzyl

• Methyl

In Merrifield solid phase synthesis, what is the solid support typically made of?

• Glass beads

• Polystyrene resin

• Silica gel

• Cellulose

Which of the following is a disadvantage of using carbodiimide for carboxylic acid activation?

• It is too expensive

• It can lead to racemisation

• It is not reactive enough

• It is too volatile

Which of the following is a common side chain protecting group for serine in peptide synthesis?

• Benzyl

• t-Butyl

• Acetyl

• Methyl

Draw the mechanism for the activation of Fmoc-Alanine with Diisopropyl carbodiimide: