23404-09-3Relevant articles and documents
Synthesis and Structure-Activity Relationships of Ring-Opened Bengamide Analogues against Methicillin-Resistant Staphylococcus aureus?
Yu, Chen-Xi,Wei, Bing-Yan,Kong, Xue-Qing,Yang, Cai-Guang,Nan, Fa-Jun
supporting information, p. 671 - 676 (2021/02/12)
Methicillin-resistant Staphylococcus aureus (MRSA) has become a major threat on public health because of the increase of clinically isolated strains that exhibit resistance to many antibiotics. Therefore, development of new antibiotics for the treatment of MRSA infection is a sustained challenge. We have previously identified a ring-opened bengamide analogue L472-2 that displays moderate activity against the growth of S. aureus. In our previous work, we started from L472-2 and identified a class of analogues containing alkynyl groups which have the potential to activate SaClpP activity but moderate antibacterial activity. Herein, we focused on the antibacterial activity of L472-2, and a novel series of ring-opened bengamide analogues were synthesized and their activities were evaluated against MRSA. By conducting a compact analysis of the structure-activity relationships (SAR) of these analogues, we found that an adamantane ethanol ester bengamide 2j showed excellent antibacterial activity towards six S. aureus strains, including MRSA, while it does not activate ClpP. Therefore, these bengamide analogues represent a new class of candidates that suppress MRSA viability.
Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis
Siebert, David C.B.,Sommer, Roman,Pogorevc, Domen,Hoffmann, Michael,Wenzel, Silke C.,Müller, Rolf,Titz, Alexander
supporting information, p. 2922 - 2929 (2019/12/23)
The argyrins are secondary metabolites from myxobacteria with antibiotic activity against Pseudomonas aeruginosa. Studying their structure–activity relationship is hampered by the complexity of the chemical total synthesis. Mutasynthesis is a promising approach where simpler and fully synthetic intermediates of the natural product’s biosynthesis can be biotechnologically incorporated. Here, we report the synthesis of a series of tripeptide thioesters as mutasynthons containing the native sequence with a dehydroalanine (Dha) Michael acceptor attached to a sarcosine (Sar) and derivatives. Chemical synthesis of the native sequence D-Ala-Dha-Sar thioester required revision of the sequential peptide synthesis into a convergent strategy where the thioester with sarcosine was formed before coupling to the Dha-containing dipeptide.
Synthesis of new glycopeptides; application to the preparation of N-(5-enkephalyl)-α-D-galacto-oct-6-enopyranuronamide
Coutrot, Philippe,Grison, Claude,Lecouvey, Marc
, p. 27 - 46 (2007/10/03)
The synthesis of new glycopeptides in which the peptidic moiety is linked to the glucidic part through a keto α,β-ethylenic handle is described.Two routes have been studied.The first strategy devised uses Horner reagents derived from N-substituted (diethy
First-Order Rate Constans for the Racemization of Each Component in a Mixture of Isomeric Dipeptides and their Diketopiperazines
Smith, Grant Gill,Baum, Rocky
, p. 2248 - 2255 (2007/10/02)
L-Alanylglycine (L-Ala-Gly), glycyl-L-alanine (Gly-L-Ala), and c-L-Ala-Gly were racemized at 120 deg C in aqueous phosphate-buffered solutions at pH 8.0, a pH value near maximum racemization.The kinetics were followed by regression analysis.The racemization of Ala-Gly and Gly-Ala closelly followed reversible first-order kinetics.The initial rate of racemisation of DKP was fast but soon slowed, likely because of hydrolysis to the dipeptides.The resulting rate was similar to that of the dipeptides.The observed racemization rate constans of the dipeptides and DKP were shown to be independent of the concentration of the peptides and the concetration of buffer.Component isolation studies using preparative TLC and chiral-phase GC analysis, coupled with computer analysis, showed an equilibrium existing between Ala-Gly, Gly-Ala, and DKP and the individual rates of racemization.At equilibrium, the mole fractions are as follows: Ala-Gly, 0.57; DKP, 0.22; Gly-Ala, 0.21.The rate constant for racemization of DKP was only 2 times that of Gly-Ala and 7 times the rate of Ala-Gly.Ala-Gly racemized 20 times and Gly-Ala 66 times faster than free alanine.The results support the influence of neighboring groups in the racemization of dipeptides.Factors that contribute to the rapid racemization (epimerization) are discussed.
Neighboring Residue Effects: Evidence for Intramolecular Assistance to Racemization or Epimerization of Dipeptide Residues
Smith, Grant Gill,Evans, Robert C.,Baum, Rocky
, p. 7327 - 7332 (2007/10/02)
Dipeptides, their methyl esters, diketopiperazines (DKP), and N-substituted derivatives were racemized at high temperatures (approximately 120 deg C) in aqueous phosphate buffered solutions at pH values close to pH of maximum racemization (approximately 8).The racemization of the dipeptides Ala-Gly and Gly-Ala followed reversible first-order kinetics.The initial rate of racemization of DKP was very fast but soon slowed down, supposedly due to hydrolysis.The resulting rate was similar to that of the dipeptides.Esters of dipeptides followed racemization patterns similar to DKP.The racemization rate constants of the dipeptides studied were shown to be independent of the concentration of the dipeptide and the concentration of buffer.A carboxy-terminal proline residue greatly increased the rate of racemization (epimerization) of the amino-terminal residue.Increasing the basicity of the N-terminal amino acid residue increased the rate of racemization (or epimerization) of the C-terminal residue unless the C-terminal was sterically hindered as the Ile and Val.Decreasing the basicity of the N-terminal amino acid residue decreased racemization or epimerization for nonhindered C-terminal amino acids.These results support the influence of neighboring groups in the racemization or epimerization of dipeptides.DKP formation is a competing reaction allowing racemization or epimerization in dipeptides.Dipeptide racemization or epimerization is proposed to be the result of combination of intramolecular base assistance and DKP formation.
