New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• representatives of this class are fluorescein and rhodamine (Figure 1), which have been applied as chemosensors [4] and have been widely exploited in various areas such as cell biology, microscopy, biotechnology, and ophthalmology due to their versatile photophysical properties. However, the chemical modification

• of this evergreen class of dyes is still an ongoing process [5][6]. Fluorescein is the most widely used fluorescent probe in biological applications and in particular for covalently labeling proteins. Rhodamine derivatives are robust dyes that find application as fluorophores for microscopy, in cell

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• entrance via confocal laser scanning microscopy [30]. Several types of dye moiety/CD derivatives have been suggested as "switch on" or "switch off" fluorescent chemical sensors. In these systems, the complexation with a guest molecule allows to enhance or decrease the fluorescence intensity. Two water

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• ]. Thus, compound 28 (Figure 9b) was prepared and found to inhibit formation of the MBNL-CUGexp nuclear foci in DM1 model cells. Indeed, it was possible to follow live cells and watch the foci dissolve in real time using time-lapse confocal microscopy [77]. The logical next step was increasing affinity

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• phenomenon represents a significant contribution of TM-βCD high coverage. To further explore the effect of the TM-βCD and TM-γCD encapsulations, the surface topography of the copolymers was also investigated by atomic force microscopy (AFM) analysis. Some representative images obtained for the non-rotaxane 3

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• either undergo significant shifts or be masked by broad bands of the hosts RAMEB and HPBCD in the spectra of the materials prepared by kneading. Preparation and preliminary characterization of crystalline inclusion complexes between 2ME and the hosts DIMEB and TRIMEB Hot stage microscopy (HSM) was

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• microscopy and flow cytometry methods for preclinical research [13][14][15][16] (Figure 2). Many of these fluorescent probes are used as imaging reagents to quantify the level of cell death in a range of biomedical samples [17]. We also developed some nuclear isotopic labeled probes for in vivo imaging of

• conjugated with targeting ligands, and bioimaging studies have shown that they enable fluorescence microscopy and mesoscale imaging of diverse biomedical targets such as tumors, infection, bone, cell death, and brown adipose tissue [37][38] (Figure 3). Several of these molecular probes are commercially

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• ). Equipment Dynamic light scattering (DLS) Hydrodynamic diameters and zeta potentials were measured on a Zetasizer NanoZS (Malvern Instrument Ltd, Malvern, United Kingdom) at 20 °C, with a laser wavelength of 633 nm and a scattering angle of 173°. High resolution scanning electron microscopy (HR-SEM) All SEM

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• particle size of the primary CD nanogel and the appearance of a new peak at a larger diameter (120 nm) may be due to the self-assembly of the primary CD nanogels at 0.1 wt % concentration in water. The scanning electron microscopy (SEM) measurement was carried out in order to observe the self-assembled

• nanogel structures. Prior to the observation, the CD nanogel was immediately frozen, using liquid nitrogen, and freeze-dried. The diameters of the spherical particles range from 50 to 100 nm (Figure 3B), confirming the formation of self-assembled CD nanogels in water. The transmission electron microscopy

• be noted that reducing a volume ratio of oil (Φoil = 0.3) does not result in a phase separation for either oil (data not shown). Optical microscopy observation confirmed the presence of dispersed oil droplets for both O/W emulsions as shown in Figure 4C (for n-dodecane) and 4D (for toluene). The

Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties

• Xiang Sun,
• Guoqiao Lai,
• Zhifang Li,
• Yuwen Ma,
• Xiao Yuan,
• Yongjia Shen and
• Chengyun Wang

Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255

• microscopy (SEM) and X-ray diffraction (XRD), which showed that the self-assembly ability of T1 was better than that of T2. The results revealed that more urethane groups in a molecule did not necessarily instigate self-assembly. UV–vis and FTIR spectra were measured to explore noncovalent interactions. The

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• calorimeter with a scanning temperature range from 20–80 °C at a scanning rate of 10 °C/min. The transmission electron microscopy image was observed using a JEM 1200EX (JEOL) transmission electron microscope operating at 120 KV. Photographs of the formation of a PEP100M15CD hydrogel. WXRD patterns of γ-CD (A

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• -Lac-β-CyD was found to be associated with U18666A-treated HepG2 cells, higher than TRITC-β-CyD, which is lacking the lactose moiety (Figure 4A,B). Next, we examined the intracellular distribution of TRITC-Lac-β-CyD by confocal laser scanning microscopy (Figure 5). It should be noted that cellular

• fluorescence derived from TRITC and LysoTracker® in U18666A-treated HepG2 cells was detected by confocal laser scanning microscopy. The fluorescence intensities were determined by a BZ-II analyzer (Keyence, Osaka, Japan). Intracellular distribution of cholesterol U18666A-treated HepG2 cells (5 × 104 cells/35

Profluorescent substrates for the screening of olefin metathesis catalysts

• Raphael Reuter and
• Thomas R. Ward

Beilstein J. Org. Chem. 2015, 11, 1886–1892, doi:10.3762/bjoc.11.203

• and fluorescence showed good agreement. These profluorescent substrates could be prototypes for more complex structures that could find applications in ring-closing metathesis for biological applications by fluorescence microscopy. Experimental General Methods: The 1H and 13C NMR spectra were recorded

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• hand, the conductivities of the corresponding neutral nanoobjects are determined by pulse-radiolysis or flash-photolysis time-resolved microwave conductivity techniques [48][49]. Current-sensing atomic force microscopy (CS-AFM) and combination of scanning tunneling microscopy and spectroscopy (STM/STS

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• synthesized hexa-peri-hexabenzocoronene cyclophane 201a–c. They studied their properties by carrying out differential scanning calorimetry (DSC), optical microscopy, wide-angle X-ray scattering (WAXD), and scanning tunneling microscopy (STM). Tunneling spectroscopy reveals a diode-like behavior which

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene: the effect of planarisation on charge transport properties

• Rupert G. D. Taylor,
• Joseph Cameron,
• Iain A. Wright,
• Neil Thomson,
• Olena Avramchenko,
• Alexander L. Kanibolotsky,
• Anto R. Inigo,
• Tell Tuttle and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1148–1154, doi:10.3762/bjoc.11.129

• compound 1. Atomic force microscopy (AFM) was used in order to analyse the surfaces of the devices fabricated. Shown below in Figure 6 are images from devices containing compound 2 with OTS and PFBT/OTS SAMs. The images look similar with a combination of small and large clusters covering the surface. This

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• to gel phase transition under visible irradiation. The corresponding visual images are shown in Figure 3. Scanning electron microscopy studies To obtain a visual insight into the morphology of the aggregation mode, the typical structures of the xerogels prepared by the freeze-drying of the three gels

• spectroscopy (IR) was measured on a Nicolet 6700 spectrometer from 4000 to 500 cm−1 at room temperature. The samples were prepared as KBr pellets. The morphology of the gel samples were examined by scanning electron microscopy (SEM, S5200, FEI Company) under an acceleration voltage of 30 kV. UV–vis absorption

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

• Yunfei Wang and
• Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

• equipped with a copper X-ray source with a wavelength of 1.54 nm. Scanning electron microscopy (SEM) was performed on an FEI MLA 650 FEG microscope. BET surface area and pore size analyses were performed on a Micromeritics TriStar II Plus instrument. The degassing was done on a Flow Prep 060 instrument

Terminal lipophilization of a unique DNA dodecamer by various nucleolipid headgroups: Their incorporation into artificial lipid bilayers and hydrodynamic properties

• Emma Werz and
• Helmut Rosemeyer

Beilstein J. Org. Chem. 2015, 11, 913–929, doi:10.3762/bjoc.11.103

• -2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), was studied by single molecule fluorescence spectroscopy and microscopy with the help of an optically transparent microfluidic sample carrier with perfusion capabilities. The incorporation of the lipo-oligonucleotides into the bilayer was studied

• determination of the bilayer brightness using fluorescence microscopy [8]. In the following, we describe the insertion of six unique single-stranded DNA dodecamers carrying different nucleolipid head groups as well as cyanine-5 (Cy5) at the 5’-(n−1) position in artificial lipid bilayers. In this case we varied

• the cis channel followed by cycles of incubation and perfusion leads to the binding of the corresponding oligomer on the membrane, as detected by microscopy and single molecule fluorescence spectroscopy. The kinetics of the binding of the different bilayer-bound oligonucleotides were studied as well

Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

• Stefanie Krysiak,
• Qiang Wei,
• Klaus Rischka,
• Andreas Hartwig,
• Rainer Haag and
• Thorsten Hugel

Beilstein J. Org. Chem. 2015, 11, 828–836, doi:10.3762/bjoc.11.92

• microscopy (AFM). The comparison of single catechols (dopamine) with multiple catechols on hyperbranched polyglycerols (hPG) at various pH and dwell times allowed us to further increase our understanding. In particular, we were able to elucidate how to achieve strong bonds of different valency. It was

• concluded that hyperbranched polyglycerols with added catechol end groups are promising candidates for durable surface coatings. Keywords: adhesion; atomic force microscopy; catechol; hyperbranched polyglycerols; valency; Introduction While underwater glues are still a challenge for industrial adhesive

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• systems. Keywords: molecular rupture mechanism; multivalency; malleability; pyridine coordination compounds; scanning force microscopy; Introduction In a multivalent molecular system, two partners interact with each other through two or more non-covalent equivalent interaction centers. This principle is

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

• Daniel Schöne,
• Boris Schade,
• Christoph Böttcher and
• Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

• Daniel Schone Boris Schade Christoph Bottcher Beate Koksch Institute of Chemistry and Biochemistry - Organic Chemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany Electron Microscopy, Freie Universität Berlin, Fabeckstr. 36a, 14195 Berlin, Germany 10.3762/bjoc.11.89 Abstract

Regulation of integrin and growth factor signaling in biomaterials for osteodifferentiation

• Qiang Wei,
• Theresa L. M. Pohl,
• Anja Seckinger,
• Joachim P. Spatz and
• Elisabetta A. Cavalcanti-Adam

Beilstein J. Org. Chem. 2015, 11, 773–783, doi:10.3762/bjoc.11.87

• limited. As a result, cells are self-renewed without loss of phenotype [32]. In a recent study, how nanoscale clustering of integrin ligands alters the mechano-regulation of integrins has been revealed with the assistance of molecular tension fluorescence microscopy [33]. In the step of nascent adhesion

Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection

• Fatemeh Sheikhi Mehrabadi,
• Hanxiang Zeng,
• Mark Johnson,
• Cathleen Schlesener,
• Zhibin Guan and
• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86

• maintaining its low cytotoxicity (Figure 4). Cellular uptake and confocal microscopy The cellular uptake and localization of fluorescently labeled siRNA/AAdPG complexes were quantified using flow cytometry and confocal microscopy (Figure 6). By comparing the cellular uptake of dPG-NH2 functionalized solely

• transfection media, the cells were trypsinized and collected via centrifugation. The transfected cells were analyzed by FACS to determine the mean Cy3-fluoroscence of each sample. Confocal microscopy Unmodified NIH 3T3 fibroblast cells were seeded at a density of 10,000 cells/well on an 8-well chamber slide

Glycodendrimers: tools to explore multivalent galectin-1 interactions

• Jonathan M. Cousin and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2015, 11, 739–747, doi:10.3762/bjoc.11.84

• mediated interactions. Dynamic light scattering and fluorescence microscopy were used to study the multivalent interaction of galectin-1 with the glycodendrimers in solution, and glycodendrimers were observed to organize galectin-1 into nanoparticles. In the presence of a large excess of galectin-1

• nanoparticles were characterized using dynamic light scattering (DLS) and fluorescence microscopy (FM) when varying ratios of galectin-1 were added to the glycodendrimers. The galectin-1/glycodendrimer nanoparticle aggregates were then used to inhibit the galectin-1 induced aggregation of DU145 human prostate

• -functionalized PAMAM dendrimers 1–4 were determined by fluorescence microscopy (FM) and dynamic light scattering (DLS). For fluorescence microscopy, galectin-1 was labeled with AlexaFluor-555, and aggregation was characterized when a large, medium, or slight excess of galectin-1 was used relative to the

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• density variation of functional groups on the PEG scaffold using unsaturated carboxylic acids (crotonic acid, acrylic acid, methacrylic acid) as grafting units for mannose conjugation. We showed by a range of analytic techniques (ATR–FTIR, Raman microscopy, zeta potential and titration) that this

• deformation is a measure of the sum over all specific interactions between the carbohydrate ligand and the protein receptor layer. Detection of the interaction energy is straight forward using the contact area of the SCP with the protein layer via reflection interference contrast microscopy (RICM) (Figure 1

• whole bulk of the particles. This was confirmed via confocal Raman microscopy indicating a homogeneous distribution of functional groups (Supporting Information File 1, S2). The observed increase in grafting density of MA over AA is well established in the literature [13][17][18]. For example, Yang et