Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• activity of GAT1 protein during purification exists, a near-neutral high-salt buffer containing 4 M MgCl2 (pH 6) (Figure 3) was selected to avoid the irreversible aggregation of GAT1, which may be caused by high pH values. A second purification step with SE-FPLC was performed to remove the eluted

• fusion protein. In this work, the baculovirus expression system was used for the expression of the protein of interest. The full-length GAT1 protein is composed of twelve highly hydrophobic TM domains, which promote strong aggregation behavior of the protein, if it is isolated from the membrane. The

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• . The UV–vis spectra of annealed films of the polymers at 130 °C show an apparent red shift in the onset absorption because of an increased aggregation of the polymer chains upon heating. The optical band gaps of P1, P2, and P3 were calculated from the onset of the absorption as 1.95 eV, 1.93 eV and

Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

• Markus Börgardts and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 768–778, doi:10.3762/bjoc.13.76

• aggregation induced self-quenching and singlet oxygen dependent dye degradation can be efficiently prevented [14][15]. By the rigid silica host framework bimolecular photochemical reactions are also suppressed [16]. Additionally, mesoporous materials possess the crucial advantage that they can be synthesized

• loadings of the hybrids are correlated with the surface area of the silica material, typically 700 m2·g−1, self-quenching effects should occur at loadings higher than 10 μmol·g−1 as illustrated in Figure 3 [24]. Although aggregation-induced self-quenching can be prevented by covalently ligating dye

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• adsorption on the atomically dispersed Pd sites. Electrostatic stabilization of Pd atoms was ascribed to a strong interaction with the nitrogen-coordinating species on the basis of DFT calculations. Effective stabilization also prevented site aggregation, resulting in pretty constant catalytic activity over

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• increasing the temperature from 15 to 90 °C, 52% of the fluorescence was lost, without any red or blue shift in the emission maximum. The mechanism for this change was also attributed to nanoparticle aggregation, with CD agglomeration occurring at higher temperatures. Two different groups reported, nearly

• green fluorescent N/P-doped CDs with QYs of up to 17% with an excitation independent emission which could be modulated by varying the concentration of Na4P2O7 in the starting mixture. Also, the higher the concentration of pyrophosphate, the less aggregation product was observed. The resultant CDs were

• down hyaluronate (Scheme 15). As hyaluronate is used to stabilise the AuNPs, any enzymatic activity that degrades the polymer would result in AuNP aggregation, which in turn modulates the absorption properties of the AuNPs. The latter has a favourable overlap with the emission spectra of CDs, when

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• -cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in

• ), to increase the aqueous solubility and to prevent the undesired aggregation of the PS inside the cell. Another advantage offered by the covalently connected CD–PS systems is the encapsulation of hydrophobic photoactivatable drug molecules in the CD cavity, enabling thereby the application of these

• the studied medium and consequently it would lead to false positive results in microscopic studies or in undesired aggregation of the free PS. To circumvent this drawback and to ensure the stability of the dye-appended CD derivatives, different strategies using thioureido [3] or amide [22] connections

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• studies have shown that most of the compounds 26 exhibited a good inhibitory activity against AChE. For instance, compounds 26d and 26i demonstrated IC50 values of 14.8 and 18.6 nM, respectively and a remarkably inhibition of Aβ aggregation. The environmentally benign synthesis of 1-indanones from 3

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• ) aggregation [14], which is a major cause of neurodegeneration in Huntington’s disease. Although there are numerous reports available on the study of these analogues, an automated, chemoselective alternative to the synthesis is not yet available. The most common synthetic approach starts from m-(chlorosulfonyl

• -Sulfamoylbenzamides as Sirtuin 2 inhibitors (SIRT2) or suppressor of polyglutamine aggregation (polyQ). Syrris AFRICA system. Screening results of the different conditions for the best chemoselectivity with aniline and azepane as (F2) and (F3), respectively. Screening results of the different conditions for the best

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• form a multicellular organism. Eventually, they culminate in fruiting bodies to spread some of the population as dormant spores into the environment. Secondary metabolites often constitute the key signaling molecules in these developmental processes [3][4]. For instance, aggregation of the amoebae is

• signs of aggregation became visible. Cells were washed three times in 17 mM phosphate buffer (pH 6.2) to remove bacteria and suspended at 2 × 107 cells/mL in 17 mM phosphate buffer (pH 6.2) with shaking at 150 rpm. After 1 h of starvation, 1 µM glorin (Phoenix Pharmaceuticals, Burlingame CA, USA

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• -stacking, donor–acceptor interaction, electrostatic, metal coordination, hydrophobic forces or van der Waals’ interactions [4][5][6]. We know a great deal about the aggregation behaviour of gelator molecules from many studies conducted during the past several years. However, rational design and accurate

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• catalytic activity. The aggregation is a slow process in distilled water, but happens instantly in the presence of salts, e.g., in tap water, surface waters and waste waters. β-CD can be used for stabilization of colloidal TiO2 systems [33] – at least in distilled water – as it is adsorbed on the surface of

• which effectively protects nanoTiO2 in aqueous media against the precipitating effect of different salts in tap water. We used turbidity and light scattering measurements for studying the aggregation behavior of nanoTiO2. In a second step, the photocatalytic properties of the stabilized nanoTiO2

• start to aggregate and form larger particles enhancing the turbidity of dispersion. The turbidity (the haziness of the dispersion caused by particles invisible for the naked eye) was measured to monitor the aggregation of the particles of nanoTiO2. Various monomer and polymer CD derivatives were studied

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• leads to aggregation and inactivation under physiological conditions, causing a reduced production of reactive oxygen species [26]. To overcome this drawback, we considered to immobilize the squaraines onto a platform that provides spatial separation (Figure 1). Our platforms of choice are vesicles self

• applications when a well-known PS, phthalocyanine, was used to decorate the cyclodextrin vesicles [37][38]. The immobilization led to an increased photoactivity of the phthalocyanines due to suppression of aggregation and inactivation of the PS at the surface of the CDVs. In this contribution we show that

• for the CDV without affecting its photochemistry. In addition, it is expected that the aggregation of squaraine will be supressed by immobilization at the CDV surface. Ultimately, the photoactive squaraine can be combined with other functional guests, such as targeting units and tracers, to further

Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

• Kohei Koyanagi,
• Yoshinori Takashima,
• Takashi Nakamura,
• Hiroyasu Yamaguchi and
• Akira Harada

Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244

• functions of supramolecular catalysts. CD derivatives are widely used in radical polymerization to dissolve hydrophobic monomers in aqueous solutions [48][49][50][51][52][53][54] and to control the aggregation of polymers [55][56][57][58]. Although supramolecular catalysts with CDs as monomer recognition

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• integrated with functional fragments upon coordination with metals can undergo significant changes in molecular shape and aggregation state that can be used in the design of smart adaptive materials [1][2]. Some important bis- and trishydrazone ligands used in catalysis, coordination and supramolecular

Inhibition of peptide aggregation by means of enzymatic phosphorylation

• Kristin Folmert,
• Malgorzata Broncel,
• Hans v. Berlepsch,
• Christopher H. Ullrich,
• Mary-Ann Siegert and
• Beate Koksch

Beilstein J. Org. Chem. 2016, 12, 2462–2470, doi:10.3762/bjoc.12.240

• protofilaments and on to insoluble amyloid fibrils, and we found a remarkable directing effect from β-sheet-rich structures to unfolded structures in the initial growth phase, in which small oligomers and protofilaments prevail if the peptide is phosphorylated. Keywords: aggregation; amyloids; peptide models

• the subject of numerous studies, the pathway of aggregation from soluble α-helical-rich or partially unfolded peptides into insoluble β-sheet-rich amyloid fibrils remains unclear. Several studies discovered parameters of peptide environment, like pH [12][13], oxidative stress [14], presence of organic

• characteristics, outstanding stability, regular fibrous architecture and high synthetic accessibility with numerous chemoselective ligation and modification methods [24][25][26]. Also, various post-translational modifications, like phosphorylation or glycosylation have been studied as aggregation triggers [27][28

A direct method for the N-tetraalkylation of azamacrocycles

• Andrew J. Counsell,
• Angus T. Jones,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239

• be optimised alongside mixing performance [46], and in nanotechnology, where shaking can be used to modulate aggregation so as to favour particular nanostructures [47][48]. Otto and co-workers have investigated the influence of mechanical forces on reactivity in the context of self-replication by

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• block copolymer case, non-fluorinated segments appear to slightly frustrate the aggregation of the more fluorinated block. However, in situ temperature dependent Raman spectroscopy shows that the intramolecular order is more thermally stable in the block copolymer than in the corresponding blend

• interpretation of the vibronic structure in relation to the order in the thin film, it is worth noting that the vibronic structure of the block copolymers in both cases is less pronounced than for the corresponding blend. Considering the aformentioned link between the vibronic structure and aggregation, this

• melting and crystallization temperatures, an effect that was predominantly attributed to the increased backbone planarity and rigidity in combination with the increased aggregation it engenders [42]. In order to probe the crystallization behavior of the block copolymers and blends in thin films, DSC was

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• S4). In addition this behavior underlines that no aggregation of the molecules has to be taken into account at the concentration level of absorption and emission spectroscopy. In the UV–vis spectra, most characteristically, four absorption bands are found, three at shorter wavelengths arising from

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• still shows some large aggregates in blend films [10]. The addition of pyrrolic phenylacetylene substituents further helped to break the aggregation and to create a favorable nanoscale phase separation in blend films, leading to higher PCEs [9][10]. DFT calculations show that Zn(WS3)2 is a very large

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• majority of applications of microflow setups involved reagents in the same aggregation state (homogeneous, mostly liquid phase). In contrast, an especially complex problem beyond the scope of most microreactor setups are heterogeneous reactions [31][32] between three dispersed entities such as a liquid

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• aggregation became an issue when we attempted to sense changes in serum profiles. We overcame this issue using Nature's fluorescent polymers, namely fluorescent proteins. Using gold nanoparticles and green fluorescent protein we were able to rapidly detect very small changes in serum protein profiles in

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• optical characterization, both in solution and thin-film, indicated that PTzBDT-1 has a red-shifted optical absorption compared to PTzBDT-2, likely due to a more planar conformation of the polymer backbone promoted by the lower content of alkyl side chains. The different aggregation in the solid state

• performance is presumably attributed to the limited solubility of the PTzBDT-1 in organic solvents resulting in enhanced aggregation and poor intermixing with the acceptor material in the active layer. Keywords: alkyl side chains; benzodithiophene; bulk heterojunction solar cells; 2D conjugated polymers

• aggregation, in solution and solid state, of the polymer chains. The solution absorption spectra of the polymers (Figure 1A) exhibit an evident red-shift (~20 nm) of the λmax of PTzBDT-1 compared to PTzBDT-2 (550/598 nm and 530/574 nm, respectively). Moreover, PTzBDT-1 shows a broader spectrum in comparison

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• consistent with the increment in the oscillator strength revealed by the DFT calculation results. The ICT absorption peaks are slightly red-shifted and broadened in the solid thin films as compared to those in the chloroform solutions, which can be ascribed to molecular aggregation in the condensed solid

Artificial Diels–Alderase based on the transmembrane protein FhuA

• Hassan Osseili,
• Daniel F. Sauer,
• Klaus Beckerle,
• Marcus Arlt,
• Tomoki Himiyama,
• Tino Polen,
• Akira Onoda,
• Ulrich Schwaneberg,
• Takashi Hayashi and
• Jun Okuda

Beilstein J. Org. Chem. 2016, 12, 1314–1321, doi:10.3762/bjoc.12.124

• oxidized to Cu(II) by contamination with air. Cu(II) led to protein aggregation and precipitation. This was shown in an independent experiment. When one equiv of Cu(NO3)2·3H2O was added to a solution of FhuA ΔCVFtev, the protein precipitated rapidly and quantitatively. MALDI–TOF–MS analysis for the whole

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• sector in generating structure and function diverse O-nitrate esters for use as in vivo NO-donors. In this context particular emphasis has been placed on developing O-nitrate esters as biologically active agents that act on acetylcholinesterase (AChE), amyloid-βx-42 (Aβ42) aggregation, cyclooxygenase-II