Question

Show schematically how merrifield synthesis works. (no formulas required) What type of polymers are producted by this technique? Discuss advantages and dissadvantages.

Answer 1

Merrifield introduced the concept of solid phase synthesis to achieve more efficient synthesis of peptides. In SPPS, the peptide chain was assembled in a stepwise manner while the C-terminal end of the peptide was anchored to an inert cross-linked polymer support and the peptide was grown from C-terminal to N-terminal residue. Merrifield demonstrated the feasibility of the idea by synthesizing a model tetra peptide 9 L-leucyl-L-alanyl-glycyl-L-valine. Simultaneously with Merrifield, Letsinger and Kornet reported the synthesis of a dipeptide, L-leucyl-glycine on a ''Popcorn pol'er support"using a different chemical strategy. The N-terminal amino acid was anchored to the polymer support and the peptide was grown from N-terminal to C-terminal.

Advantage & diss advantage

This technique is not so popular because the cleavage from the support under mild condition is not possible and always there is a problem of racemisation. Merrifield's invention formed the basis of a new technique of peptide synthesis, which has been used till now with several methodological improvements and refinements. The design of polymer support, 3.1 1-16 its chemistry and applications for SPPS have been extensively reviewed. These refinements and recent developments in designing solid supports and various factors involving in solid phase peptide synthesis .