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.
Depsipeptide natural products
Enterochelin is a depsipeptide that is an iron-transporter.[5]
Several depsipeptides have been found to exhibit anti-cancer properties.[6]
A depsipeptide enzyme inhibitor includes romidepsin, a member of the bicyclic peptide class, a known histone deacetylase inhibitors (HDACi). It was first isolated as a fermentation product from Chromobacterium violaceum by the Fujisawa Pharmaceutical Company.[7]
Etamycin was shown in preliminary data in 2010 to have potent activity against MRSA in a mouse model.[8] Several depsipeptides from Streptomyces exhibit antimicrobial activity.[9][10] These form a new, potential class of antibiotics known as acyldepsipeptides (ADEPs). ADEPs target and activate the casein lytic protease (ClpP) to initiate uncontrolled peptide and unfolded protein degradation, killing many Gram-positive bacteria.[11][12][13]
^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. PMID16351050.
^Walsh; Christopher T.; Jun Liu; Frank Rusnak; Masahiro Sakaitani (1990). "Molecular Studies on Enzymes in Chorismate Metabolism and the Enterobactin Biosynthetic Pathway". Chemical Reviews. 90 (7): 1105–1129. doi:10.1021/cr00105a003.
^Yurek-George, Alexander; Cecil, Alexander Richard Liam; Mo, Alex Hon Kit; Wen, Shijun; Rogers, Helen; Habens, Fay; Maeda, Satoko; Yoshida, Minoru; et al. (2007). "The First Biologically Active Synthetic Analogues of FK228, the Depsipeptide Histone Deacetylase Inhibitor". Journal of Medicinal Chemistry. 50 (23): 5720–5726. doi:10.1021/jm0703800. PMID17958342.
papuamide Ford, PW; Gustafson, KR; McKee, TC; Shigematsu, N; Maurizi, LK; Pannell, LK; Williams, DE; de Silva, ED; Lassota, P; Allen, TM; Van Soest, R; Andersen, RJ; Boyd, MR (1999). "Papuamides A-D, HIV-Inhibitory and Cytotoxic Depsipeptides from the Sponges Theonella mirabilis and Theonella swinhoei Collected in Papua New Guinea". J. Am. Chem. Soc. 121: 5899–5909. doi:10.1021/ja990582o.
neamphamide A Oku, N; Gustafson, KR; Cartner, LK; Wilson, JA; Shigematsu, N; Hess, S; Pannell, LK; Boyd, MR; McMahon, JB (2004). "Neamphamide A. A new HIV-inhibitory depsipeptide from the Papua New Guinea marine sponge Neamphius huxleyi". J. Nat. Prod. 67 (8): 1407–11. doi:10.1021/np040003f. PMID15332865.
callipeltin A Zampella, A; D'Auria, MV; Paloma, LG; Casapullo, A; Minale, L; Debitus, C; Henin, Y (1996). "Callipeltin A, an Anti-HIV Cyclic Depsipeptide from the New Caledonian Lithistida Sponge Callipelta sp.". J. Am. Chem. Soc. 118 (26): 6202–9. doi:10.1021/ja954287p.
