scholarly journals A mixed chirality α-helix in a stapled bicyclic and a linear antimicrobial peptide revealed by X-ray crystallography

2021 ◽  
Author(s):  
Stéphane Baeriswyl ◽  
Hippolyte Personne ◽  
Ivan Di Bonaventura ◽  
Thilo Köhler ◽  
Christian van Delden ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Crystal Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
Α Helix

We report the first X-ray crystal structures of mixed chirality α-helices comprising only natural residues as the example of bicyclic and linear membrane disruptive amphiphilic antimicrobial peptides containing seven l- and four d-residues.

scholarly journals Mixed Chirality α-Helix in a Stapled Bicyclic and a Linear Antimicrobial Peptide Revealed by X-Ray Crystallography

2021 ◽  
Author(s):  
stéphane Baeriswyl ◽  
Hippolyte Personne ◽  
Ivan Di Bonaventura ◽  
Thilo Köhler ◽  
Christian van Delden ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Md Simulations ◽  
Isobutyric Acid ◽  
Cd Spectra ◽  
X Ray ◽  
X Ray Crystallography ◽  
Left Handed ◽  
Amino Isobutyric Acid ◽  
Α Helix ◽  
Protein Environment

<p></p><p>The peptide α-helix is right-handed when containing amino acids with L-chirality, and left-handed with D-chirality, however mixed chirality peptides generally do not form α-helices unless the non-natural residue amino-isobutyric acid is used as helix inducer. Herein we report the first X-ray crystal structures of mixed chirality α-helices in short peptides comprising only natural residues at the example of a stapled bicyclic and a linear membrane disruptive amphiphilic antimicrobial peptide (AMP) containing seven L- and four D-residues, as complexes of fucosylated analogs with the bacterial lectin LecB. The mixed chirality α-helices are superimposable to their parent homochiral α-helices and form under similar conditions as shown by CD spectra and MD simulations but are resistant to proteolysis. The observation of mixed chirality α-helix with only natural residues in the protein environment of LecB suggests a vast unexplored territory of α-helical mixed chirality sequences and their possible use for optimizing bioactive α-helical peptides.</p><br><p></p>

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

Synthesis, characterization and crystal structures of novel fluorinated di(thiazolyl)benzene derivatives

2019 ◽  
Vol 6 (6) ◽  
pp. 780-790 ◽  
Author(s):  
Maciej Barłóg ◽  
Ihor Kulai ◽  
Xiaozhou Ji ◽  
Nattamai Bhuvanesh ◽  
Somnath Dey ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Benzene Derivatives ◽  
Stille Coupling ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted

A series of 11 novel fluorinated and non-fluorinated di(thiazolyl)benzenes have been synthesized via microwave assisted Stille coupling and characterized using X-ray crystallography.

Synthesis and crystal structures of three novel benzimidazole/benzoindolizine hybrids

2016 ◽  
Vol 71 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Aissa Chibani ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimethyl Maleate

AbstractThree benzoindolizine derivatives, 1, 2, and 3, were obtained via 1,3-dipolar cycloaddition. The reaction of 1-(2′-benzimidazolylmethyl)isoquinolinium ylides with dimethyl acetylenedicarboxylate gave a mixture of pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (1) and 1,10b-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (2) derivatives containing a benzimidazole moiety. The reaction of this isoquinolinium N-ylide with dimethyl maleate gave an unexpected 2,3-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (3). The structures of all reported compounds have been examined by X-ray crystallography, mass spectrometry, and NMR spectroscopy.

New insights into chalcogen bonding provided by co-crystal structures of benzisoselenazolinone derivatives and nitrogen bases

CrystEngComm ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1539-1542 ◽  
Author(s):  
Thomas Fellowes ◽  
Jonathan M. White
Keyword(s):  
Crystal Structures ◽  
X Ray ◽  
Nitrogen Bases ◽  
X Ray Crystallography ◽  
Derivatives Of

A number of derivatives of benzisoselenazolinones, including the drug ebselen, have been synthesized, and their interactions with various nitrogen bases characterized through X-ray crystallography.

scholarly journals Sesquiterpene Lactones from Inula oculus-christi

2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Mahmoud Mosaddegh ◽  
Maryam Hamzeloo Moghadam ◽  
Saeedeh Ghafari ◽  
Farzaneh Naghibi ◽  
Seyed Nasser Ostad ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Sesquiterpene Lactones ◽  
X Ray ◽  
X Ray Crystallography ◽  
First Time

Inula oculus-christi L. (Compositae) extract was chromatographed and three sesquiterpene lactones ergolide, gaillardin and pulchellin C were isolated. The structures of these compounds were determined by analysis of their spectroscopic data, and their crystal structures were defined using X-ray crystallography; the isolation of ergolide and pulchellin C is reported for the first time from this species. These three compounds were evaluated for their in vitro cytotoxic activity against MDBK, MCF7 and WEHI164 cells; ergolide and gaillardin exhibited lower and significantly different IC50 values compared with pulchellin C ( p<0.001).

Syntheses, Crystal Structures and Electrochemical Properties of Acetylacetonato-Ruthenium Complexes Containing Substituted Pyridine Ligands

2013 ◽  
Vol 68 (9) ◽  
pp. 993-999 ◽  
Author(s):  
Xiuli Wu ◽  
Rufei Ye ◽  
Ai-Quan Jia ◽  
Qun Chen ◽  
Qian-Feng Zhang
Keyword(s):  
Electrochemical Properties ◽  
Crystal Structures ◽  
Zinc Dust ◽  
Ruthenium Complexes ◽  
Reducing Agent ◽  
Molecular Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
Crystal And Molecular Structures ◽  
Pyridine Ligands

Treatment of Ru(acac)3 with 2-cyano-pyridine and 3,5-dimethyl-pyridine in the presence of zinc dust as reducing agent in refluxing THF afforded the ruthenium(II) complexes cis-[RuII(acac)2(2- CN-py)2] (1) and cis-[RuII(acac)2(3,5-Me2-py)2] (2), respectively. Interaction of Ru(acac)3 with 3- Me-pyridine and 3,5-Me2-pyridine in the presence of Br2 in refluxing THF gave the ruthenium(III) complexes [RuIII(acac)Br2(3-Me-py)2] (3) and [RuIII(acac)Br2(3,5-Me2-py)2] (4), respectively. The four complexes have been spectroscopically and electrochemically characterized, and their crystal and molecular structures have been established by X-ray crystallography

Crystal structures of N6-modified-aminoacid/peptide nucleobase analogs: hybrid adenine–glycine and adenine–glycylglycine molecules

2018 ◽  
Vol 42 (18) ◽  
pp. 14742-14750 ◽  
Author(s):  
Angel García-Raso ◽  
Angel Terrón ◽  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Jhon J. Molina ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Crystal Structures ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography

Anion–π interactions in crystal structures of N6-modified-aminoacid and dipeptide adenine analogs are investigated using X-ray crystallography and DFT calculations.

The Preparation and Crystal Structures of a Series of Urea Adducts: with Fumaric Acid (2 : 1), with Itaconic Acid (1 : 1) and with Cyanuric Acid (1 : 1)

1997 ◽  
Vol 50 (10) ◽  
pp. 1021 ◽  
Author(s):  
Graham Smith ◽  
Colin H. L. Kennard ◽  
Karl A. Byriel
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Itaconic Acid ◽  
Fumaric Acid ◽  
Cyanuric Acid ◽  
X Ray ◽  
X Ray Crystallography ◽  
Donor And Acceptor ◽  
Bonding Systems ◽  
Urea Adducts

The adducts of a series of compounds with urea (ur) have been prepared and their crystal structures determined by X-ray crystallography. These are the adducts with the unsaturated aliphatic acids fumaric acid [(fumaric acid)(ur)2] (1) and itaconic acid [(itaconic acid)(ur)] (2), and with cyanuric acid [(cyanuric acid)(ur)] (3). All structures have extensive hydrogen-bonding systems in which most of the urea donor and acceptor sites are involved.

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