Potential of acylated peptides to target the influenza A virus

• Daniel Lauster,
• Damian Pawolski,
• Julian Storm,
• Kai Ludwig,
• Rudolf Volkmer,
• Henry Memczak,
• Andreas Herrmann and
• Sumati Bhatia

Beilstein J. Org. Chem. 2015, 11, 589–595, doi:10.3762/bjoc.11.65

• supramolecular structures [20][21]. Stearylated peptides, closely related to C18-s2s, C18-rs2s and C18-PeBGF assemble as supramolecular structures with a critical micelle concentration (CMC) between 0.8–0.9 µM and a size between 0.2 and 2.3 µm depending on the peptide concentration [12]. The rather large size

• indicates the formation of rather large structures different from a simple sphere-like micelle. To verify and characterize the assembly of our peptides into higher-order structures, we studied exemplarily the organization of C18-PeBGF by dynamic light scattering (DLS) and transmission electron microscopy

• amphiphilic peptides do not behave like typical micelle-forming molecules. Although we found smaller supramolecular assemblies at 20 µM C18-PeBGF, there is a strong tendency to form larger and stable supramolecular arrangements. Indeed, our TEM images implicate a rather amyloid-like character of C18-PeBGF and

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• , see Figure 7). Upon addition of the non-ionic surfactant Triton X-100 with concentrations above the critical micelle concentration (ccmc = 0.24 mM [29]), the signal of the excimer emission completely disappears, pointing to an incorporation of the AR in micelles in the straight conformation (Figure 7

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• method is unsuitable, for instance due to the instability of the cation formed, Chiba and co-workers have proposed a reversible capture method [42]. Using liquefiable micelle-like microparticles containing a thiomaleimide unit, N-acyliminium ions generated electroorganically can be intercepted and tagged

• in situ. The tagged and now stable “reactive intermediate” can then be removed from the electrolyte solution. Warming the tagged “reactive intermediate” converts the micelle (eicosane, a thermosensitive alkane) from solid to liquid and releases the thiomaleimide tagged N-acyliminium ion. Further

A study on the inhibitory mechanism for cholesterol absorption by α-cyclodextrin administration

• Takahiro Furune,
• Naoko Ikuta,
• Yoshiyuki Ishida,
• Hinako Okamoto,
• Daisuke Nakata,
• Keiji Terao and
• Norihiro Sakamoto

Beilstein J. Org. Chem. 2014, 10, 2827–2835, doi:10.3762/bjoc.10.300

• : Micelle formation of cholesterol with lecithin and bile salts is a key process for intestinal absorption of lipids. Some dietary fibers commonly used to reduce the lipid content in the body are thought to inhibit lipid absorption by binding to bile salts and decreasing the lipid solubility. Amongst these

• ][38]. Thus, the mechanism behind RM showing a higher micellar cholesterol solubility than the control is considered to be related to its micelle stabilization function. Conversely, although Inu and PDX were reported to lower lipid contents [39][40], our current study shows that these dietary fibers

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

• Yamei Zhao,
• Wei Tian,
• Guang Yang and
• Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

• resulting multifunctional, polymeric micelle nanocarriers provide higher drug loading capacity compared to their counterparts due to the introduction of the HBPCSi segments. Furthermore, drug molecules can be simultaneously encapsulated into the hydrophobic core layer and the hydrophilic shell layer of

• in the micellization process. Self-assembly behaviour of P3 in aqueous solution After the synthesis of P3 with amphiphilic characteristics, the corresponding micelle system with a core–shell structure can be formed in aqueous solution by self-assembly. This is driven by the strong hydrophobic

• –hydrophilic interactions between the inner core and the outer shell. The micelles were prepared by directly adding water to a DMF solution of P3 until the required amount of water for micelle formation was reached. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements were

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• the surfactant tail volume (V), the surfactant tail length (t) and the area of the surfactant headgroup at critical micelle concentration (Acmc), Equation 5: Surfactants with lower FFV values are expected to be effective CO2-philes, corresponding to improved solubility of surfactants and therefore

• volume of surfactant in the entire system. The fragment volume at the interface is calculated using the interfacial thickness and the area of surfactant headgroups at critical micelle concentration. Increased Φsurf corresponds to greater separation between two phases at the interface. Viscosifiers for

• parameters as a function of M+, as interfacial packing density and limiting the area of the head group at the critical micelle concentration (Acmc) are dependent on the identity of M+ (highlighted through surface tensiometric measurements). Decreases in cmc, Acmc and surface tension were observed with a

Influence of cyclodextrin on the solubility and the polymerization of (meth)acrylated Triton^® X-100

• Melanie Kemnitz and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2176–2183, doi:10.3762/bjoc.8.245

• the poly(ethylene glycol) substituent is hydrophilic. Because of this amphiphilic character, Triton® X-100 can be described as a short AB block co-oligomer [1]. Long amphiphiles are relatively flexible and provide a lower critical micelle concentration (CMC) [2]. The CMC of Triton® X-100 is 0.22 mM [3

Impact of cyclodextrins on the behavior of amphiphilic ligands in aqueous organometallic catalysis

• Hervé Bricout,
• Estelle Léonard,
• Christophe Len,
• David Landy,
• Frédéric Hapiot and
• Eric Monflier

Beilstein J. Org. Chem. 2012, 8, 1479–1484, doi:10.3762/bjoc.8.167

• RAME-β-CD/phosphane ratio of 1:1, while a huge drop in TOF was observed for a RAME-β-CD/phosphane ratio of 2:1. Conversely, high RAME-β-CD/phosphane ratios yielded an increase in TOF. The results could be interpreted as follows. First, for a RAME-β-CD/phosphane ratio of around 1:1, the micelle

• structure was slightly altered because of the interaction of RAME-β-CD with the micelle constituents, especially the inclusion process (Figure 4). As the micelle dynamics was improved, the exchanges between the hydrophobic substrate-containing micelle core and the catalyst-containing aqueous solution were

• (solid lines) and RAME-β-CD (dotted lines) on the surface tension of 1 mM aqueous solutions of phosphanes 1–4 (20 °C). Equilibria in a phosphane-based micelle/RAME-β-CD mixture. Turnover frequency (TOF) as a function of the RAME-β-CD/phosphane ratio in the Pd-catalyzed cleavage of allyl undecyl carbonate

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

• micelle-bound form, resulting in the insertion of the Trp side chain into the hydrophobic core of the micelle. Calcein leakage All four peptides were tested for their ability to induce the release of the self-quenching fluorescent dye, calcein, from calcein-encapsulated LUVs [14][15]. All of the peptides

• -helix. When compared to the curve of gp41w-4R in 50% TFE, the traces from the micelle-containing samples show little difference, indicating that the conformation of gp41w-4R is similar in all these environments. In the presence of 50% TFE, gp41w also adopts a largely α-helical conformation, but in the

• presence of micelles there may be other structural elements that contribute to the CD spectra, as evidenced by the strong minima at ~218 nm seen in both the SDS and DPC traces. However, the micelle samples still have minima at 208 nm and maximum values at 195 nm, both of which are characteristic of helical

Olefin metathesis in nano-sized systems

• Didier Astruc,
• Abdou K. Diallo,
• Sylvain Gatard,
• Liyuan Liang,
• Cátia Ornelas,
• Victor Martinez,
• Denise Méry and
• Jaime Ruiz

Beilstein J. Org. Chem. 2011, 7, 94–103, doi:10.3762/bjoc.7.13

• catalysis in water and with down to 0.04 % of the second-generation Grubbs catalyst 7 for RCM, (Table 1) [63]. The dendrimer 11 contains triethylene glycol termini that solubilize it in water. In this way, the dendrimer serves as a molecular micelle [64][65] to solubilize the hydrophobic catalysts and

Surfactant catalyzed convenient and greener synthesis of tetrahydrobenzo[a]xanthene-11-ones at ambient temperature

• Pravin V. Shinde,
• Amol H. Kategaonkar,
• Bapurao B. Shingate and
• Murlidhar S. Shingare

Beilstein J. Org. Chem. 2011, 7, 53–58, doi:10.3762/bjoc.7.9

• C14. It is of note to point out that the addition of TTAB converted the initially floating reaction mass into a homogeneous mixture, which on stirring became a white turbid emulsion. This observation implies, that there was formation of micelles or micelle-like colloidal aggregates. Indeed, formation

• effect. In micellar solution, organic substrates are pushed away from water molecules towards the hydrophobic core of micelle droplets thus inducing efficient collisions between organic substrates which eventually enhance the reaction rate and result in rapid reactions in water. The hydrophobic interior

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• homogenized by stirring, the scattering disappeared. This indicates that the micelle formation is a dynamic and reversible process. When the pH value reaches 4.8 (point 1), aggregates were visible over the entire volume, and above 5.3 (point 2) the micelles formation was complete. The pKa for 2-ethylpyridine

Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

• Katja Hofmann,
• Ingolf Kahle,
• Frank Simon and
• Stefan Spange

Beilstein J. Org. Chem. 2010, 6, No. 79, doi:10.3762/bjoc.6.79

• a high synthetic effort. Micelle techniques commonly used to carry out reactions between water-soluble and insoluble compounds cannot be cleanly applied to modify polyelectrolytes [25]. Alternatively, water-soluble polymers can be modified by the introduction of alkyl or aryl groups, thus mediating

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

Ring opening metathesis polymerization-derived block copolymers bearing chelating ligands: synthesis, metal immobilization and use in hydroformylation under micellar conditions

• Gajanan M. Pawar,
• Jochen Weckesser,
• Siegfried Blechert and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, No. 28, doi:10.3762/bjoc.6.28

• Schrock catalyst Mo(N-2,6-Me2-C6H3)(CHCMe2Ph)(OCMe(CF3)2)2 [Mo] to yield poly(M1-b-M2). In water, poly(M1-b-M2) forms micelles with a critical micelle-forming concentration (cmc) of 2.8 × 10−6 mol L−1; Reaction of poly(M1-b-M2) with [Rh(COD)Cl]2 (COD = cycloocta-1,5-diene) yields the Rh(I)-loaded block

• micellar core, where, upon micelle formation of the functionalized block copolymer, the monomer will also accumulate. This leads to high educt concentrations at the polymer-bound catalyst, often resulting in high reaction rates in water [8]. We recently reported on the synthesis of RhI and IrI complexes of

• was converted into M2 via quaternization of the tertiary amine with methyl iodide. Synthesis of homo- and block copolymers via ROMP [12][13] ROMP has already been used for the synthesis of micelle-forming block copolymers [14], however, the one used in this study, i.e. poly(M1-b-M2), required special