38017-89-9Relevant articles and documents
Synthesis of Cyclic Peptidomimetics via a Pd-Catalyzed Macroamination Reaction
Hopkins, Brett A.,Smith, Graham F.,Sciammetta, Nunzio
, p. 4072 - 4075 (2016)
A new method to access cyclic peptidomimetics via a Pd-catalyzed macroamination reaction is presented. Natural amino acid amines are revealed as proficient coupling partners in these transformations. With a commercially available CPhos G3 catalyst system and substrates bearing diverse amino acid and aryl halide backbones, the unique head to side-chain (or side-chain mimic) macrocycles are afforded with ring sizes from 11 to 23 members in yields up to 84%.
Effect of solvent on the cis-trans conformational equilibrium of a proline imide bond of short model peptides in solution
Sugawara, Masae,Tonan, Kenji,Ikawa, Shun-Ichi
, p. 1305 - 1316 (2001)
Proton NMR spectra of proline-containing short peptides with N-terminal sequences of N-acetyl-prolyl- (Ac-Pro-) N-tert-butoxycarbonyl-phenylalanyl-prolyl- (Boc-Phe-Pro-) and N-tert-butoxycarbonyl-leucyl-prolyl- (Boc-Leu-Pro-) were measured in mixed solvents of hexadeuterodimethylsulfoxide and deuterochloroform (CDCl3). Population ratios of cis and trans conformers with respect to the proline imide bond and chemical shifts of NH protons were obtained as a function of a CDCl3 fraction of solvent. With increasing fraction of CDCl3, the trans percentages of the Ac-Pro- imide bonds increased. On the other hand, those of Boc-Phe-Pro- decreased, and those of Boc-Leu-Pro- exhibited middle tendency. From the solvent-dependent variation of the chemical shifts of the NH protons, intramolecular hydrogen bonds that stabilize the trans form of Ac-Pro- and the cis form of Boc-Phe-Pro- were discussed. For the Ac-Pro- peptides, only the trans forms are found to the compatible with 7-, 10-, and 13-membered hydrogen-bonded rings that would be similar to the ordinary secondary structures, γ- and β-turns and α-helix, respectively. For the cis form of Boc-Phe-Pro-R (R = O-methyl or glycyl-O-ethyl), the hydrogen-bonded structure is found to be similar to the type-VIa β-turn. On the other hand, for Boc-Phe-Pro-Pro-Leu-Gly-NH2, it has been suggested that two different hydrogen bonds, which are different from that of the type-VIa β-turn, support each other and cooperatively stabilize the cis form.
Unambiguous stereochemical assignment of cyclo(Phe-pro), cyclo(leu-pro), and cyclo(val-pro) by electronic circular dichroic spectroscopy
Dewan, Faizunnahar,Domzalski, Alison,Kawamura, Akira,Margent, Liliana,Pilarsetty, Naga Vara Kishore,Vigo, Valeria,Xu, Yujia
, (2021/10/12)
2,5-diketopiperazines (DKPs) are cyclic dipeptides ubiquitously found in nature. In particular, cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro) are frequently detected in many microbial cultures. Each of these DKPs has four possible stereoisomers due to the presence of two chirality centers. However, absolute configurations of natural DKPs are often ambiguous due to the lack of a simple, sensitive, and reproducible method for stereochemical assignment. This is an important problem because stereochemistry is a key determinant of biological activity. Here, we report a synthetic DKP library containing all stereoisomers of cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro). The library was subjected to spectroscopic characterization using mass spectrometry, NMR, and electronic circular dichroism (ECD). It turned out that ECD can clearly differentiate DKP stereoisomers. Thus, our ECD dataset can serve as a reference for unambiguous stereochemical assignment of cyclo(Phe-Pro), cyclo(Leu-Pro), and cyclo(Val-Pro) samples from natural sources. The DKP library was also subjected to a biological screening using assays for E. coli growth and biofilm formation, which revealed distinct biological effects of cyclo(D-Phe-L-Pro).
Photoredox-Mediated Reaction of gem-Diborylalkenes: Reactivity Toward Diverse 1,1-Bisborylalkanes
Eghbarieh, Nadim,Kumar, Nivesh,Masarwa, Ahmad,Shames, Alexander I.,Stein, Tamar
supporting information, p. 5360 - 5364 (2020/04/23)
The use of gem-diborylalkenes as radical-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemical conversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes. This method expl
Chemical profiling of HIV-1 capsid-targeting antiviral PF74
Casey, Mary C.,Do, Ha T.,Du, Haijuan,Hachiya, Atsuko,Kirby, Karen A.,Sahani, Rajkumar Lalji,Sarafianos, Stefan G.,Tedbury, Philip R.,Vernekar, Sanjeev Kumar V.,Wang, Lei,Wang, Zhengqiang,Xie, Jiashu,Zhang, Huanchun
supporting information, (2020/05/19)
The capsid protein (CA) of HIV-1 plays essential roles in multiple steps of the viral replication cycle by assembling into functional capsid core, controlling the kinetics of uncoating and nuclear entry, and interacting with various host factors. Targetin
Antidiabetic in vitro and in vivo evaluation of cyclodipeptides isolated from Pseudomonas fluorescens IB-MR-66e
Lozano-González,Ovalle-Magallanes,Rangel-Grimaldo,De La Torre-Zavala,Noriega,Tovar-Palacio,Tovar,Mata
supporting information, p. 7756 - 7762 (2019/05/27)
Three cyclodipeptides [cyclo(l-Pro-l-Leu), 1; cyclo(l-Pro-l-Val), 2; and cyclo(l-Pro-l-Phe), 3] were isolated from Pseudomonas fluorescens IB-MR-66e. The structures were established by spectral means and corroborated by synthesis. The antidiabetic potential of compounds 1-3 was explored in vivo, in vitro and in silico. The three peptides showed important inhibitory activity against the α-glucosidase enzyme. Further analysis in vivo using a sucrose tolerance test corroborated that compounds 1 and 3 (1-30 mg kg-1) significantly reduced the postprandial state. Peptide 1 (1-30 mg kg-1) also reduced the postprandial peak after a glucose challenge and exhibited significant hypoglycemia during an insulin tolerance test; thus, its antidiabetic action involved also an improvement of insulin utilization not related to Akt phosphorylation nor to an increment in mitochondrial bioenergetics nor insulin secretion.
Synthesis of 3-Benzylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione
Gaidukevich,Rudenkova,Popova,Nikolaevich,Knizhnikov
, p. 1562 - 1564 (2019/01/04)
3-Benzylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione [cyclo(Pro-Phe)] was synthesized by cyclization of prolylphenylalanine and phenylalanylproline methyl esters which were prepared from the corresponding Boc-protected amino acids.
Heteroatom-Interchanged Isomers of Lissoclinamide 5: Copper(II) Complexation, Halide Binding, and Biological Activity
Xie, Sida,Savchenko, Andrei I.,Kerscher, Marion,Grange, Rebecca L.,Krenske, Elizabeth H.,Harmer, Jeffrey R.,Bauer, Michelle J.,Broit, Natasa,Watters, Dianne J.,Boyle, Glen M.,Bernhardt, Paul V.,Parsons, Peter G.,Comba, Peter,Gahan, Lawrence R.,Williams, Craig M.
supporting information, p. 1465 - 1476 (2018/04/06)
Cyclic peptides, especially those produced by marine cyanobacteria symbionts, are considered to play an important ecological role in host defence. Chemists have long compared the cyclic peptide cavitand architecture with that of macrocyclic ligands, and proposed that they mediate metal-ion transport. The study presented herein investigated the metal chelation of non-natural heteroatom-interchanged (HI) isomers of lissoclinamide 5, by using MS, EPR, and DFT calculations. The latter identified three possible structures for the CuII complex with natural lissoclinamide 5, with the most likely determined to be that with the metal ion bound through the nitrogen donors of the thiazoles and one deprotonated amide. For HI-lissoclinamide 5 the calculations suggest that the CuII ion is bound in a bidentate manner by the oxazoline nitrogen atom and one deprotonated amide nitrogen atom, with the S donor of the thiazole not involved in coordination. Along with evidence of copper binding these systems also bound halide ions. Evaluation of the anti-cancer properties demonstrated that the biological activity of HI-lissoclinamide 5 against T24 bladder cells was eleven-fold lower as compared to natural lissoclinamide 5. Addition of a CuII salt had no effect on the activity of lissoclinamide 5. Overall, this comprehensive study of the HI concept has demonstrated that small changes propagate dramatic effects in complexation, halide binding, and biological activity.
A mechanochemical approach to access the proline-proline diketopiperazine framework
Pétry, Nicolas,Benakki, Hafid,Clot, Eric,Retailleau, Pascal,Guenoun, Farhate,Asserar, Fatima,Sekkat, Chakib,Métro, Thomas-Xavier,Martinez, Jean,Lamaty, Frédéric
supporting information, p. 2169 - 2178 (2017/11/16)
Ball milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently, the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline-proline dipeptides under solvent-free conditions. A deprotection-cyclization sequence yielded the corresponding diketopiperazines that were obtained with a high stereoselectivity which could be explained by DFT calculations. Using this method, an enantiopure disubstituted Pro-Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill.
Synthesis of cytotoxic cyanobactin, Wewakazole B
Nayani, Kiranmai,Anwar Hussaini
supporting information, p. 1166 - 1169 (2017/03/02)
We report herein the synthesis of cytotoxic cyanobactin, Wewakazole B through an efficient solution-phase approach. The key steps of the synthesis are the macrocyclic lactamization of linear dodecapeptide and construction of two hexapeptides with three di
