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Search for "bilayer" in Full Text gives 63 result(s) in Beilstein Journal of Organic Chemistry.
Drug targeting to decrease cardiotoxicity – determination of the cytotoxic effect of GnRH-based conjugates containing doxorubicin, daunorubicin and methotrexate on human cardiomyocytes and endothelial cells
Beilstein J. Org. Chem. 2018, 14, 1583–1594, doi:10.3762/bjoc.14.136
- environment, due to the electric insulator character of intact surface membranes composed of the phospholipid bilayer. Application of cytotoxic compounds results in disturbed electrophysical integrity (decreasing value of impedance) of surface membranes as a signal of cell death. While cell physiological
Steric “attraction”: not by dispersion alone
Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125
- * hyperconjugative interaction) [17], and a similar argument was used to suggest the possibility of manipulating the band gap of patterned hydrogenated graphene C4H bilayer by an external electric field [27]. Furthermore, Schreiner et al. showed that approx. 10% of the total interaction energy in the tris(3,5-di
- dimers. (A) Dispersion is insufficient to bend the heptacene σ-dimer, but becomes sizable enough in nonacene [2]. (B) Bare hexaphenylethane is not thermodynamically stable, but its all-meta-tert-butyl derivative is [3][4]. (C) Thermodynamically stable (at B97D/6-31G(d,p) level) bilayer of a fully
Design and biological characterization of novel cell-penetrating peptides preferentially targeting cell nuclei and subnuclear regions
Beilstein J. Org. Chem. 2018, 14, 1378–1388, doi:10.3762/bjoc.14.116
- nuclei; cell-penetrating peptides; nucleoli; subcellular targeting; Introduction Various drugs act on targets that are located within the nucleus, the control center of the eukaryotic cell. A lipid bilayer membrane, which is perforated with nuclear pore complex structures through which the transfer of
Nanoreactors for green catalysis
Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61
- ]. Polymersomes comprise an aqueous lumen and hydrophobic membrane. Such hydrophilic and hydrophobic compartments are capable of accommodating hydrophilic (e.g., enzymes) or hydrophobic catalysts (e.g., metal catalysts) in their lumen or bilayer, respectively [28][79]. In an aqueous environment the hydrophobic
- hydrophobic membrane and as a consequence a higher reaction rate. Dergunov et al. reported on the design of a porous polymeric nanoreactor with a lipid bilayer for coupling reactions [87]. These nanocapsules were loaded with palladium catalysts and successfully used in Suzuki, Sonogashira and Heck cross
- embedded in the bilayer. Reprinted with permission from [21]. Copyright 2007 American Chemical Society. Representation of DSN-G0. Reprinted with permission from [100]. The multivalent esterase dendrimer 5 catalyzes the hydrolysis of 8-acyloxypyrene 1,3,6-trisulfonates 6a–c. Reprinted with permission from
Remarkable functions of sn-3 hydroxy and phosphocholine groups in 1,2-diacyl-sn-glycerolipids to induce clockwise (+)-helicity around the 1,2-diacyl moiety: Evidence from conformation analysis by 1H NMR spectroscopy
Beilstein J. Org. Chem. 2017, 13, 1999–2009, doi:10.3762/bjoc.13.196
- ; deuterium labeling; sn-glycerol; glycerolipids; glycerophospholipids; helicity; Karplus equation; proton NMR spectroscopy; staggered conformers; Introduction Glycerophospholipids, constituting the basic elements of cytoplasm bilayer membranes, are responsible for several cell functions [1][2][3]. These
Chemical systems, chemical contiguity and the emergence of life
Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155
- for the determination of environmental conditions conducive to the self-assembly of several cellular-like components, such as bilayer membranes [15] and simple energy systems [16], or dynamic processes, such as growth and division [17][18] and potential evolution [19]. However, the experimental set
- nucleic acid oligomers [53][54][55]. The presence of the mineral support is crucial here as it permits the preservation of the amphiphile bilayer structure during drying, thereby promoting the conversion of an “unreactive” organization (free floating vesicles and free monomers) into reactive chemical
- activity, the inserted PAH molecules in turn contributed to stabilizing the aggregates and reducing the bilayer permeability to additional small solutes [74]. That is, feedback interactions between system components significantly increase the probability of coupled functionality, in this case coupling of a
2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization
Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148
- to eight weeks Keeping membrane proteins properly folded outside of a biological membrane is a challenging task. Detergents are needed to refold the applied membrane proteins after their extraction from the natural bilayer environment [35][36][37][38][39][40]. In case of FhuA, so far, refolding has
Grip on complexity in chemical reaction networks
Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147
- of a bilayer network composed of the mechanical action of a temperature-responsive gel coupled with various exothermic reactions. Reprinted with permission from [34], copyright 2012 Nature Publishing Group. (b) Small dynamic combinatorial library made from dithiol building blocks. Adapted with
Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience
Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114
From chemical metabolism to life: the origin of the genetic coding process
Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111
- function associated to this view is that the cell separates between an inside and an outside. In 1935, James Danielli proposed with Hugh Davson that this embodiment was achieved by formation of a bilayer made of amphiphilic lipid molecules [11]. This process is entropy-driven (life belongs to physics, it
- to understand the way proteins interact with membrane lipids, and our knowledge in the domain is still far from complete. There exist many models describing the operation (including ideas about the asymmetry of the bilayer, its local changes and lipid rafts). Work exploring the way proteins are
Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface
Beilstein J. Org. Chem. 2017, 13, 1099–1105, doi:10.3762/bjoc.13.109
- ; membrane pressure; membrane probes; monolayers; Introduction Physical triggers are a major regulator of biological processes. The lateral bilayer membrane pressure, e.g., influences the nucleation [1] and shape changes [2] of lipid domains, it gates mechanosensitive pores [3] and globally organizes cell
- directionally into lipid bilayer membranes. In order to use fluorescent flipper mechanophores for biological measurements, it is crucial to understand the exact relation between surface pressure and their spectroscopic properties. In earlier studies [8], the fluorescence was qualitatively determined in
- . Monolayers at the air/water interface are well known models for biological membranes, avoiding trans-bilayer leaflet correlation effects [11][12][13][14]. Various techniques exist to probe the surface pressure and the lateral organization of the monolayer [14]. Using monolayers of pure flipper probes, we
Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids
Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99
- flexible nanofibres at 27 °C and further to small elongated micelles at 45 °C. Furthermore, the miscibility of the bolalipid with bilayer-forming phosphatidylcholines (DMPC, DPPC, and DSPC) was investigated by means of DSC, TEM, FTIR, and small angle X-ray scattering (SAXS). We could show that the PC
- -C18pPhC18-PC is partially miscible with saturated phosphatidylcholines; however, closed lipid vesicles with an increased thermal stability were not found. Instead, bilayer fragments and disk-like aggregates are formed. Keywords: aggregation behaviour; bolaamphiphiles; bolalipids; membrane lipids; mixing
- into the bilayer was observed [28]. The reason for this behaviour is that packing problems due to the mismatch between the large space requirement of the PC headgroup of PC-C32-PC and the small cross-sectional area of its single alkyl chain arise. The insertion of a PC-C32-PC molecule in a stretched
Membrane properties of hydroxycholesterols related to the brain cholesterol metabolism
Beilstein J. Org. Chem. 2017, 13, 720–727, doi:10.3762/bjoc.13.71
- maintaining the membrane’s barrier function by increasing the bilayer packing density through condensing the phospholipids. Furthermore, cholesterol is an important player in the dynamic domain structure of the plasma membrane and the formation of lateral lipid domains with relevance to membrane protein
- the presence of 20 mol % of the respective hydroxysterols or cholesterol. The 2H NMR spectra (not shown) exhibited for all samples the typical superposition of Pake doublets with varying quadrupolar splittings as well-known for a lamellar bilayer membrane in the liquid-crystalline phase. From the 2H
- and sphingomyelin being the basis for lipid segregation and, finally, domain formation. What is the physiological consequence of the data presented? We could show that hydroxycholesterols at similarly large membrane concentrations like endogenous cholesterol do not disturb the bilayer structure of the
How and why kinetics, thermodynamics, and chemistry induce the logic of biological evolution
Beilstein J. Org. Chem. 2017, 13, 665–674, doi:10.3762/bjoc.13.66
- of nucleic acid duplexes as well as that of phospholipids to form a bilayer membrane). On the other hand, even though the Second Law must always remain an inescapable constraint, a simple drift towards the equilibrium state is not sufficient to account for the evolutionary changes of life. More
A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation
Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17
- interdigitated bilayer structure. The molecules are oriented side by side such that each hexadecyl alkyl chain is sandwiched between two such chains. The high-intensity peak at 12.75° (d-spacing value of 6.93 Å which is comparable to the width of TPM-G5, 6.99 Å) can be attributed to the distance between adjacent
A self-assembled cyclodextrin nanocarrier for photoreactive squaraine
Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248
- solution in a round bottom flask. Hydration and extrusion with a Liposofast extruder and membranes with 100 nm pore size yield bilayer vesicles of an approximate size of 100 nm. CDVs were decorated with AdSq by simple addition of the AdSq to the aqueous dispersion of the CDVs. Interestingly, the
Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents
Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77
- postulated that this lipophilic side chain may not be necessary for target inhibition, but for cellular uptake through the lipid bilayer of the cytoplasmic membrane, as an increased lipophilicity is advantageous for this [77][114]. Consequently, several lipophilic derivatives 91a–d were prepared (Figure 9
Smart molecules for imaging, sensing and health (SMITH)
Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274
- surface of biological membranes [9][10]. Biomembrane science is very challenging because the self-assembled bilayer is a soft and dynamic object that is hard to characterize with spectroscopic methods. To paraphrase a former US president, “we pursue biomembrane science not because it is easy but because
Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations
Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267
- for instance the wormlike micelles formed by the cetyltrimethylammonium cations, investigated at various salt concentrations to assess their stability against rupture in smaller spherical micelles [36], or more recently a bilayer of aCDs functionalized through an anthraquinone moiety mimicking a small
- or bilayer, or vesicles and nanospheres at appropriate concentrations. In the recent past, some of these structures have been selected to yield versatile and reliable carriers for drug delivery [3][50], and even for molecular recognition of polymers [51]. In this scenario, the proposed study can open
Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners
Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208
- peptides (AMPs) [4] and ceragenins I (Figure 1) [5]. These CSAs selectively bind to the over expressed negatively charged peripheral phospholipids on the internal bacterial cell membranes. Following membrane association, deformation occurs causing bilayer destabilization and cell lysis [6]. According to
Terminal lipophilization of a unique DNA dodecamer by various nucleolipid headgroups: Their incorporation into artificial lipid bilayers and hydrodynamic properties
Beilstein J. Org. Chem. 2015, 11, 913–929, doi:10.3762/bjoc.11.103
- oligonucleotides (LONs 10–15), each terminally lipophilized with different nucleolipid head groups, were synthesized using the recently prepared phosphoramidites 4b–9b. The insertion of the LONs within an artificial lipid bilayer, composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl
- -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
- with respect to efficiency (maximal bilayer brightness) as well as stability against perfusion (final stable bilayer brightness). Attempts to correlate these parameters with the log P values of the corresponding nucleolipid head groups failed, a result which clearly demonstrates that not only the
Potential of acylated peptides to target the influenza A virus
Beilstein J. Org. Chem. 2015, 11, 589–595, doi:10.3762/bjoc.11.65
- have been partially neutralized by the liposomes, either by attachment and/or incorporation into the lipid bilayer. Very likely, in case of stearylated peptides, we surmise incorporation into the bilayer via the fatty acyl chain. To verify the association with lipid membranes exemplarily, we
Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs
Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310
- either nearly insoluble in water or the binding constants are rather low [32][33][34]. We focussed our effort on the design of hydrophilic and/or amphiphilic CD thioethers, because only amphiphilic molecules can form [35][36] or incorporate into bilayer membranes [37][38]. Amphiphilic CD carriers can
- enter a bilayer membrane to support the API to overcome cellular barriers, such as the intestinal barrier [39] or the blood-brain barrier (BBB) [40]. Long alkyl chains (C4–C12) have already been attached via thioether or sulfoxide linkages to all primary positions by Kawabata and Ling et al. to form
Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens
Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273
- interaction of the nonionic surfactants with lipid membranes by formation of channels through the membrane [68]. More recently, Groot and Rabone claimed that the inclusion of nonionic surfactants reduces the extensibility and the maximum stress that the bilayer can withstand [69]. These modifications bring
Specific DNA duplex formation at an artificial lipid bilayer: fluorescence microscopy after Sybr Green I staining
Beilstein J. Org. Chem. 2014, 10, 2307–2321, doi:10.3762/bjoc.10.240
- describes the immobilization of different probe oligonucleotides (4, 7, 10) carrying each a racemic mixture of 2,3-bis(hexadecyloxy)propan-1-ol (1a) at the 5’-terminus on a stable artificial lipid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn
- -glycero-3-phosphocholine (POPC). The bilayer separates two compartments (cis/trans channel) of an optical transparent microfluidic sample carrier with perfusion capabilities. Injection of unlabeled target DNA sequences (6, 8, or 9), differing in sequence and length, leads in the case of complementarity to
- the formation of stable DNA duplexes at the bilayer surface. This could be verified by Sybr Green I double strand staining, followed by incubation periods and thorough perfusions, and was visualized by single molecule fluorescence spectroscopy and microscopy. The different bilayer-immobilized
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