13734-41-3Relevant articles and documents
The role of the disulfide bond in amyloid-like fibrillogenesis in a model peptide system
Das, Apurba Kumar,Drew, Michael G. B.,Haldar, Debasish,Banerjee, Arindam
, p. 3502 - 3507 (2005)
Three terminally protected short peptides Bis[Boc-D-Leu(1)-Cys(2)-OMe] 1, Bis[Boc-Leu(1)-Cys(2)-OMe] 2 and Bis[Boc-Val(1)-Cys(2)-OMe] 3 exhibit amyloid-like fibrillar morphology. Single crystal X-ray diffraction analysis of peptide 1 clearly demonstrates that it adopts an overall extended backbone molecular conformation that self-assembles to form an intermolecular hydrogen-bonded antiparallel supramolecular β-sheet structure in crystals. Scanning electron microscopic (SEM) images, transmission electron microscopic (TEM) images and Congo red binding studies vividly demonstrate the amyloid-like fibril formation of peptides 1, 2 and 3. However, after reduction of the disulfide bridge of peptides 1, 2 and 3, three newly generated peptides Boc-D-Leu(1)-Cys(2)-OMe 4, Boc-Leu(1)-Cys(2)-OMe 5 and Boc-Val(1)-Cys(2)-OMe 6 are formed and all of them failed to form any kind of fibril under the same conditions, indicating the important role of the disulfide bond in amyloid-like fibrillogenesis in a peptide model system. The Royal Society of Chemistry 2005.
Crystal-to-Crystal Synthesis of Triazole-Linked Pseudo-proteins via Topochemical Azide-Alkyne Cycloaddition Reaction
Krishnan, Baiju P.,Rai, Rishika,Asokan, Aromal,Sureshan, Kana M.
, p. 14824 - 14827 (2016)
Isosteric replacement of amide bond(s) of peptides with surrogate groups is an important strategy for the synthesis of peptidomimetics (pseudo-peptides). Triazole is a well-recognized bio-isostere for peptide bonds, and peptides with one or more triazole units are of great interest for different applications. We have used a catalyst-free and solvent-free method, viz., topochemical azide-alkyne cycloaddition (TAAC) reaction, to synthesize pseudo-proteins with repeating sequences. A designed β-sheet-forming l-Ala-l-Val dipeptide containing azide and alkyne at its termini (N3-Ala-Val-NHCH2C=CH, 1) was synthesized. Single-crystal XRD analysis of the dipeptide 1 showed parallel β-sheet arrangement along the b-direction and head-to-tail arrangement of such β-sheets along the c-direction. This head-to-tail arrangement along the c-direction places the complementary reacting motifs, viz., azide and alkyne, of adjacent molecules in proximity. The crystals of dipeptide 1, upon heating at 85 °C, underwent crystal-to-crystal polymerization, giving 1,4-triazole-linked pseudo-proteins. This TAAC polymerization was investigated by various time-dependent techniques, such as NMR, IR, DSC, and PXRD. The crystal-to-crystal nature of this transformation was revealed from polarizing microscopy and PXRD experiments, and the regiospecificity of triazole formation was evidenced from various NMR techniques. The MALDI-TOF spectrum showed the presence of pseudo-proteins >7 kDa.
Anthracene-labeled pyridinium-based symmetrical chiral chemosensor for enantioselective recognition of l-tartrate
Ghosh, Kumaresh,Sarkar, Tanmay
, p. 1342 - 1346 (2014)
A new anthracene-based chiral chemosensor 1 has been designed and synthesized. l-Valine has been used as the chiral source in the design. The chemosensor 1 has been established as an efficient enantioselective sensor for l-tartrate. While in the presence of l-tartrate the fluorescent sensor 1 in DMSO exhibits considerable increase in emission, the isomeric tartrate brings relatively small change. The enantiomeric fluorescence difference ratio (ef) has been determined to be 29.38.
An improved large scale synthesis of the Schoellkopf chiral auxiliaries: (2R)-and (2S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine
Chen, Jianxie,Corbin, Scott P.,Holman, Nicholas J.
, p. 185 - 187 (2005)
Syntheses of the Schoellkopf chiral auxiliaries have been carried out on large scale in high overall yields from D- and L-valine. This method avoids the use of highly toxic phosgene or triphosgene, low-temperature reactions, and unstable intermediates.
A short water-soluble self-assembling peptide forms amyloid-like fibrils
Ray, Sudipta,Das, Apurba K.,Drew, Michael G. B.,Banerjee, Arindam
, p. 4230 - 4232 (2006)
A water-soluble tripeptide Val-Ile-Ala (VIA) 1, bearing sequence identity with the C-terminal portion of the Alzheimer Aβ-peptide (Aβ40-42), self-assembles, in crystalline form, to produce an intermolecularly hydrogen bonded supramolecular β-sheet structure which self-associates to form straight, unbranched nanofibrils exhibiting amyloid-like behavior; in contrast, the synthetic tripeptide Ala-Val-Ile (AVI) 2 self-assembles to produce a β-sheet structure that forms branched nanofibrils which do not show any characteristic features of amyloid-like fibrils. The Royal Society of Chemistry 2006.
An amyloid-like fibril-forming supramolecular cross-β-structure of a model peptide: A crystallographic insight
Maity, Sibaprasad,Kumar, Pankaj,Haldar, Debasish
, p. 3787 - 3791 (2011)
The peptide Boc-Val-Phe-OMe 1 bearing sequence similarity with the central hydrophobic cluster (CHC) of Alzheimer's Aβ18-19 peptide self-assembles to produce amyloid-like straight unbranched fibrils as examined by atomic force microscopy and Congo red assay. Single crystal X-ray diffraction offers the atomic level structure of the supramolecular parallel β-sheet aggregation and antiparallel separation between layers (cross-β-structure).
Enantioselective sensing of lactate by pyridinium-based chiral receptor
Ghosh, Kumaresh,Majumdar, Anupam
, p. 5686 - 5689 (2013)
A simple pyridinium-based chiral receptor 1 containing l-valine as the chiral source has been designed and synthesized. The receptor 1 fluorometrically recognizes d-lactate over l-lactate in CH3CN with an enantiomeric fluorescence ratio (ef) of 5.32.
Short-peptide-based hydrogel: A template for the in situ synthesis of fluorescent silver nanoclusters by using sunlight
Adhikari, Bimalendu,Banerjee, Arindam
, p. 13698 - 13705 (2010)
N-terminally Fmoc-protected dipeptide, Fmoc-Val-Asp-OH, forms a transparent, stable hydrogel with a minimum gelation concentration of 0.2 % w/v. The gelation property of the hydrogel was investigated by using methods such as transmission electron microscopy, field-emission scanning electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy. The silver-ion-encapsulating hydrogel can efficiently and spontaneously produce fluorescent silver nanoclusters under sunlight at physiological pH (7.46) by using a green chemistry approach. Interestingly, in the absence of any conventional reducing agent but in the presence of sunlight, silver ions were reduced by the carboxylate group of a gelator peptide that contains an aspartic acid residue. These clusters were investigated by using UV/Vis spectroscopy, photoluminescence spectroscopy, high-resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) studies. Mass spectrometric analysis shows the presence of a few atoms in nanoclusters containing only Ag2. The reported fluorescent Ag nanoclusters show excellent optical properties, including a very narrow emission profile and large Stokes shift (>100 Nm). The reported fluorescent Ag nanoclusters within hydrogel are very stable even after 6 Months storage in the dark at 4 °C. The as-prepared hydrogel-nanocluster conjugate could have applications in antibacterial preparations, bioimaging and other purposes. Silver nanoparticles: An N-terminally protected dipeptide-based hydrogel has been used to make fluorescent silver nanoclusters in the presence of sunlight at room temperature and at physiological pH by using a green chemistry approach. The fluorescent silver nanoclusters exhibit interesting fluorescence properties with a very narrow emission profile and large Stokes shift that may be useful in future applications. Copyright
Synthesis and biological evaluation of new pleuromutilin derivatives as antibacterial agents
Shang, Ruo-Feng,Wang, Guan-Hua,Xu, Xi-Ming,Liu, Si-Jie,Zhang, Chao,Yi, Yun-Peng,Liang, Jian-Ping,Liu, Yu
, p. 19050 - 19065 (2014)
Several pleuromutilin derivatives possessing thiadiazole moieties were synthesized via acylation reactions under mild conditions. The in vitro antibacterial activities of the derivatives against methicillin-resistant S. aureus, methicillin-resistant S. epidermidis, S. aureus, S. epidermidis, E. coli, and B. cereus were tested by the agar dilution method and Oxford cup assay. All the screened compounds displayed potent activity. Compound 6d was the most active antibacterial agent because of its lowest MIC value and largest inhibition zone. Docking experiments were performed to understand the possible mode of the interactions between the derivatives and 50S ribosomal subunit. Moreover, the absorption, distribution, metabolism, excretion and toxicity properties of the synthesized compounds were analyzed after prediction using the Advanced Chemistry Development/Percepta Platform available online.
Synthesis of Majusculamides A and B
Nakajima, Daisuke,Sueyoshi, Kosuke,Orihara, Kensuke,Teruya, Toshiaki,Yokoshima, Satoshi
, p. 924 - 927 (2019)
The synthesis of two marine lipodipeptides, majusculamides A and B, is described. The key feature of this synthesis is the stereoselective construction of an α-methyl-β-keto-carboxamide moiety.
