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Search for "circular dichroism" in Full Text gives 139 result(s) in Beilstein Journal of Organic Chemistry.

Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

  • Evan F. Haney,
  • Leonard T. Nguyen,
  • David J. Schibli and
  • Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

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  • observed antimicrobial effects. Circular dichroism spectroscopy The backbone conformations of all of the gp41 peptide derivatives were examined by using far-UV circular dichroism (CD) spectroscopy. The resulting CD spectra of the peptides in buffer, SDS, DPC and 50% trifluoroethanol (TFE) are shown in
  • previous scan, indicating that equilibrium had been reached. Circular dichroism spectroscopy CD spectra were collected at room temperature on a Jasco J815 spectropolarimeter by using a 0.1 cm path length cuvette. Far-UV spectra of 50 μM peptide solutions were collected between 190–260 nm with a 0.5 nm step
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Published 24 Jul 2012

Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity

  • Marta De Zotti,
  • Barbara Biondi,
  • Cristina Peggion,
  • Matteo De Poli,
  • Haleh Fathi,
  • Simona Oancea,
  • Claudio Toniolo and
  • Fernando Formaggio

Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129

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  • activity. In each analogue, the single ψ[CS-NH] group was strategically incorporated either at an internal position of the amino-acid sequence, ψ[CS-NH]5, or near each of the two ends, ψ[CS-NH]2 and ψ[CS-NH]9. Moreover, the preferred conformations of these analogues were investigated by circular dichroism
  • Information File 1. Circular dichroism The CD spectra were measured on a Jasco (Tokyo, Japan) model J-715 spectropolarimeter equipped with a Haake thermostat (Thermo Fisher Scientific, Waltham, MA). Baselines were corrected by subtracting the solvent contribution. Fused quartz cells of 1.0 mm and 10.0 mm path
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Published 24 Jul 2012

Control over molecular motion using the cistrans photoisomerization of the azo group

  • Estíbaliz Merino and
  • María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

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  • conformational changes in polymers. There may also be variations in the organization of large assemblies of molecules in gels or liquid crystals. When polarized light is used, the photoisomerization often induces a reorganization of chromophores that can be reflected in the circular dichroism spectra. The basic
  • , 15 min) again enriches 46% of the trans isomer. The molecular motion was studied by circular dichroism (CD), 1H NMR and DFT calculations confirming that the change in the configuration of the N=N double bond modifies the initial position of the ferrocene resulting in an opening (cis) and closing
  • standard techniques (UV–vis, circular dichroism, chiral HPLC and NMR) has established that the chiral optical response differs greatly depending on the position of the sulfoxide group (C-2 or C-3). Cis isomers in both p-tolylsulfinyl azocompounds show an opposite arrangement of substituents around the N=N
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Published 12 Jul 2012

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

  • Raheleh Rezaei Araghi,
  • Carsten C. Mahrenholz,
  • Rudolf Volkmer and
  • Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

Graphical Abstract
  • on a C-8 column (Phenomenex® Luna C8, 10 μM, 250 mm × 21.2 mm). The identities of peptides were confirmed using an ESI–TOF instrument. Circular-dichroism (CD) spectroscopy [18]: Peptide samples were analyzed in 10 mM phosphate buffer (pH 7.4). Far-ultraviolet circular-dichroism spectra and GndHCl
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Published 25 Apr 2012

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

  • Martin Rempt,
  • Florian Weinberger,
  • Katharina Grosser and
  • Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

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  • , 5 and 6 were optically inactive and exhibited no signal in circular dichroism measurements. Both isomers 5 and 6 were already detected in the crude extracts, but also after work-up and during storage in CDCl3 further isomerization was observed. The biosynthetic origin of 5 and 6 from arachidonic
  • equipped with a Synergi MAX-RP 250 × 4.6 mm column (particle size 4 µm) from Phenomenex (Macclesfield, UK). Optical rotations were measured on a Jasco (Groß-Umstadt, Germany) 1030 polarimeter at 589 nm. Circular-dichroism spectra were recorded on a Jasco P810 instrument. Analytical thin-layer
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Published 21 Feb 2012

Fifty years of oxacalix[3]arenes: A review

  • Kevin Cottet,
  • Paula M. Marcos and
  • Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

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  • effect that occurred when the cations bound to the lower-rim esters, as indicated by increasingly complex 1H NMR patterns. When 46 bound to S-2-methylbutylammonium triflate, the presence of a chiral complex was confirmed by circular dichroism [53]. 4 Oxacalix[3]arene complexes 4.1 Complexation by parent
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Published 07 Feb 2012

Supramolecular FRET photocyclodimerization of anthracenecarboxylate with naphthalene-capped γ-cyclodextrin

  • Qian Wang,
  • Cheng Yang,
  • Gaku Fukuhara,
  • Tadashi Mori,
  • Yu Liu and
  • Yoshihisa Inoue

Beilstein J. Org. Chem. 2011, 7, 290–297, doi:10.3762/bjoc.7.38

Graphical Abstract
  • behavior of anthracenecarboxylate (AC) moieties. UV–vis, circular dichroism and fluorescence spectral studies revealed that two AC molecules are simultaneously included in the modified γ-CD cavity to form a right-handed screw and also that the naphthalene cap efficiently transfers the singlet energy to AC
  • carbonate. In contrast, capped γ-CD 6 showed a much higher solubility in water, as the naphthalene cap can hardly interact with another CD. The complexation behavior of AC with modified γ-CDs 6 and 7 was investigated by UV–vis, circular dichroism and fluorescence spectral studies. As shown in Figure 1, the
  • addition of 7 to an aqueous solution of AC (0.2 mM) caused an evident bathochromic shift of the 1La band of AC, which is probably due to the stacking complexation of two AC molecules in a single γ-CD cavity. Modified γ-CDs 6 and 7 showed moderate circular dichroism signals in the naphthalene-absorbing
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Published 07 Mar 2011

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

  • Daniel Crespy and
  • Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

Graphical Abstract
  • with a water-soluble catalyst [72]. The reaction was faster when the oil-soluble catalyst was used. Finally, helical substituted polyacetylene could be efficiently polymerized in direct miniemulsion to yield a latex displaying intense circular dichroism [73]. Particles from 60 to 400 nm could be
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Published 01 Dec 2010

Gelation or molecular recognition; is the bis-(α,β-dihydroxy ester)s motif an omnigelator?

  • Peter C. Griffiths,
  • David W. Knight,
  • Ian R. Morgan,
  • Amy Ford,
  • James Brown,
  • Ben Davies,
  • Richard K. Heenan,
  • Stephen M. King,
  • Robert M. Dalgliesh,
  • John Tomkinson,
  • Stuart Prescott,
  • Ralf Schweins and
  • Alison Paul

Beilstein J. Org. Chem. 2010, 6, 1079–1088, doi:10.3762/bjoc.6.123

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  • based on hydrogen bonding of the end-group was confirmed by IR and circular dichroism (CD) spectroscopic characterisation. The specific stereochemistry of the gelator end-groups is a crucial factor, providing an obvious analogy to molecular recognition phenomena. Small-angle neutron scattering provided
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Published 18 Nov 2010

Molecular recognition of organic ammonium ions in solution using synthetic receptors

  • Andreas Späth and
  • Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

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Published 06 Apr 2010

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

  • José L. Jiménez Blanco,
  • Fernando Ortega-Caballero,
  • Carmen Ortiz Mellet and
  • José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

Graphical Abstract
  • ranging from dimeric to octameric species (Scheme 1) [23][24]. All of these were soluble in water, DMSO and methanol, which allowed NH/ND exchange NMR experiments and circular dichroism (CD) studies to be carried out. Combined structural studies showed that a tetramer is required for an ordered secondary
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Published 22 Feb 2010

Ring strain and total syntheses of modified macrocycles of the isoplagiochin type

  • Andreas Speicher,
  • Timo Backes,
  • Kerstin Hesidens and
  • Jürgen Kolz

Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71

Graphical Abstract
  • and quantum chemical CD (circular dichroism) investigations, the absolute configuration of the first natural compound of this type, isoplagiochin C from P. deflexa, was established as (PA)-1 and the energy of racemization was calculated and measured to be 102 kJ/mol, approximately [13]. The
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Published 01 Dec 2009

Chiral amplification in a cyanobiphenyl nematic liquid crystal doped with helicene-like derivatives

  • Alberta Ferrarini,
  • Silvia Pieraccini,
  • Stefano Masiero and
  • Gian Piero Spada

Beilstein J. Org. Chem. 2009, 5, No. 50, doi:10.3762/bjoc.5.50

Graphical Abstract
  • papers, see refs [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]). Cholesteric induction has also been exploited for the assignment of the absolute configuration of chiral molecules, as a viable alternative or complement to more usual techniques such as Circular Dichroism [2][3] (for a
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Published 07 Oct 2009

Recent progress on the total synthesis of acetogenins from Annonaceae

  • Nianguang Li,
  • Zhihao Shi,
  • Yuping Tang,
  • Jianwei Chen and
  • Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

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Published 05 Dec 2008
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