Depsipeptide

A depsipeptide is a peptide in which one or more of its amide, -C(O)NHR-, groups are replaced by the corresponding ester, -C(O)OR-.[1] Many depsipeptides have both peptide and ester linkages.[2] Elimination of the N–H group in a peptide structure results in a decrease of H-bonding capability, which is responsible for secondary structure and folding patterns of peptides, thus inducing structural deformation of the helix and β-sheet structures.[2][3] Because of decreased resonance delocalization in esters relative to amides, depsipeptides have lower rotational barriers for cis-trans isomerization and therefore they have more flexible structures than their native analogs.[2][3] They are mainly found in marine and microbial natural products.[4]

Example of a depsipeptide with 3 amide groups (highlighted blue) and one ester group (highlighted green). R1 and R3 are organic groups (e. g. methyl) or a hydrogen atom found in α-hydroxycarboxylic acids. R2, R4 and R5 are organic groups or a hydrogen atom found in common amino acids.
  1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "depsipeptides". doi:10.1351/goldbook.D01604
  2. ^ a b c Avan, Ilker; Tala, Srinivasa R.; Steel, Peter J.; Katritzky, Alan R. (17 June 2011). "Benzotriazole-Mediated Syntheses of Depsipeptides and Oligoesters". The Journal of Organic Chemistry. 76 (12): 4884–4893. doi:10.1021/jo200174j. PMID 21452874.
  3. ^ a b Avan, Ilker; Hall, C. Dennis; Katritzky, Alan R. (2014). "Peptidomimetics via modifications of amino acids and peptide bonds". Chemical Society Reviews. 43 (10): 3575–3594. doi:10.1039/C3CS60384A. PMID 24626261.
  4. ^ Yasumasa Hamada; Takayuki Shioiri (2005). "Recent Progress of the Synthetic Studies of Biologically Active Marine Cyclic Peptides and Depsipeptides". Chem. Rev. 105 (12): 4441–4482. doi:10.1021/cr0406312. PMID 16351050.