Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• release of siRNA or miRNA encapsulated within them into the solution in vitro and in vivo [21]. The closed conformation of 2 with parallel alkyl chains acts as a building block of the bilayer membrane and is packed together with other lipids. When the surrounding medium becomes acidic, the tweezers adopt

• their open conformation. This causes fluctuations and local defects in the packing of a bilayer (Figure 3), leading to membrane disruption and release of active components from within the vesicles [22]. Such concept makes these tweezers good candidates for controlled drug delivery. The group of F. Wang

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• , assuming that La@C2v-C82 and the monoadducts have the same absorption coefficients. X-ray crystallography Black crystalline rods of 3a were obtained using the liquid–liquid bilayer diffusion method with 3a in a CS2 solution and an n-hexane solution in a glass tube (⌀ = 7 mm) at room temperature. The SC-XRD

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

• Ghenwa Nasr,
• Hélène Greige-Gerges,
• Sophie Fourmentin,
• Abdelhamid Elaissari and
• Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

• not considered in the literature despite the remarkable effect of CHOL on the stability of the lipid bilayer. In fact, CHOL can greatly modulate the membrane permeability: a previous work showed that increasing the CHOL content in the membrane results in a decrease in the membrane permeability in a

• dose-dependent manner [15]. Additionally, the CHOL content was demonstrated to reduce and sometimes to inhibit the permeability of DPPC vesicles induced by bioactive agents [16][17]. Given the condensing and ordering effect that CHOL exerts on the membrane, the presence of CHOL in the lipid bilayer

• molecules takes place resulting in membrane destabilization. This is illustrated by the rapid leakage of SRB loaded liposomes upon CDs exposure to membranes of different CHOL contents. After this initial effect, the CD would not influence the stability of the bilayer supposing that the membrane is re

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• -workers synthesized a helical bilayer NG by using helicene in the initial step as the linker to fuse two HBC units [48]. As shown in Scheme 6, starting from the helical alkyne 54, Sonogashira coupling with 4-tert-butyliodobenzene (55) afforded structure 56 in a 77% yield. Subsequent Diels–Alder reaction

• of 91 was significantly improved. The enantiomers of 91 were proved as NIR-CPL emitters with 600 to 800 nm range of emission and glum values of 3 × 10−3 both in solution and in the solid state. Multilayer (e.g., bilayer and trilayer) graphenes that are composed of stacked graphenic layers exhibit

• outstanding electronic and optical features which are not available with single-layer graphenes. The helical bilayer NG 58 developed by Martín and co-workers has been described. Recently, some more complex multilayer NGs were reported. As shown in Scheme 11, Tan and co-workers reported trilayer chiral

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• (like polystyrene in cyclohexane), which always show an UCST. This critical point is usually located in the semi-dilute regime and the brush can contract discontinuously or continuously [114][131]. The more complex dependencies on χ leads to a bilayer-type profile, as has been shown for PNIPAAm [132

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• known as the callus-like form [8][29]. In the second set of samples, algae were inoculated with the two marine bacteria, Roseovarius sp. MS2 and Maribacter sp. MS6, developing into a phenotype composed of bilayer cells and organised tissues, as previously reported [8]. The algal germlings incubated with

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• interesting example of the effects that long alkyl chains have on the overall packing. This is seen as the preferred alignment of alkyl chain with each other, reminiscent of a lipid bilayer (Supporting Information File 1, Figure S32) [23]. There are four motifs that contribute to the overall packing seen in

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• crystallinity (well-defined spots) and identical spacings in all systems. Image analysis revealed 0.96 ± 0.10 nm dark-contrast stripes separated by 0.69 ± 0.12 nm light-contrast stripes in all cases. The molecular model that best fits the cryo-TEM and TEM data is a bilayer, where pairs of PDI cores are coupled

• together, and the carboxylic groups of both PDIs turn outwards to the surrounding aqueous medium. The resulting 1D π-stacked bilayer structures interact via the ethylpropyl residues to form an extended bilayered crystalline sheet (Figure 3C,D,E). According to the model (Figure 3C,D,E), dark-contrast

• stripes correspond to the overlapping aromatic cores (1.1 nm), and the light-contrast stripes correspond to the ethylpropyl residues (0.6 nm), as observed in the cryo-TEM images (Figure 3A and Figure 3B). In order to validate the bilayer width of the nanocrystals, atomic force microscopy (AFM) and SAXS

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• surfactin bioactivity is specifically evoked by the surfactant activity triggering cell lysis due to penetration of the bacterial lipid bilayer membranes and the formation of ion-conducting channels [40][41][42]. The bioactivity of surfactin was shown against Listeria spp. and Legionella monocytogenes [43

Easy access to a carbohydrate-based template for stimuli-responsive surfactants

• Thomas Holmstrøm,
• Daniel Raydan and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2020, 16, 2788–2794, doi:10.3762/bjoc.16.229

• -delivery system owing to their size and the ability to carry drugs, both in the polar (core) or apolar (lipid bilayer) interior [4][5]. A challenge in liposome-based drug delivery systems is to release the drug at the place of function. This challenge has led to the development of stimuli-responsive

• mechanical impulse that can increase or decrease the distance between the two lipophilic tails, thus changing the amphiphilic properties of the molecule. Incorporating such molecules into the lipid bilayer of liposomes can result in the decomposition of the whole liposome when the stimuli-responsive

Nonenzymatic synthesis of anomerically pure, mannosyl-based molecular probes for scramblase identification studies

• Giovanni Picca,
• Markus Probst,
• Simon M. Langenegger,
• Oleg Khorev,
• Peter Bütikofer,
• Anant K. Menon and
• Robert Häner

Beilstein J. Org. Chem. 2020, 16, 1732–1739, doi:10.3762/bjoc.16.145

• )-labeled analog MPC-2 carries an additional dodecanyl linker between the citronellyl unit and the fluorophore. This is intended to increase the hydrophobic interactions between the probe and the lipid bilayer and also to increase the flexibility. More specifically, the probe should adopt a U-shaped

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• film of the alternating copolymer 6c had a bilayer lamellar structure with 7.3 Å and 22.4 Å distances, respectively (Figure 2b) [13][29][30]. Molecular modeling of the alternating copolymer 6c suggested chain lengths of 11.6 Å and 2.2 Å, respectively. The values of the observed layer distances of

• , 1134, 1052, 840, 801, 773, 754, 720, 700 cm−1. Solubility tests of alternating copolymer 6 (1 mg of material dissolved in 1 mL of the solvent). XRD measurement and prediction of the bilayer lamellar structure of polymer 6c. a) XRD analysis. b) Suggested bilayer lamellar structure. c) Side chain length

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• bilayer of the plasma membrane. In fact, the lipophilic character of similar small BTD derivatives demonstrated improved affinity for lipid-based structures, as we [42][43] and others [26][29] have shown. The intramolecular H-bond is in addition responsible for the rigidity of the structure and enables a

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

• Sachin S. Burade,
• Sushil V. Pawar,
• Tanmoy Saha,
• Navanath Kumbhar,
• Amol S. Kotmale,
• Manzoor Ahmad,
• Pinaki Talukdar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

• cation and anion transport across lipid bilayer membranes plays a crucial role in various biological processes [31][32]. Amongst these, the transport of anions is useful in regulating intracellular pH, membrane potential, cell volume, and fluid transport [33]. Any dysfunction in these processes led to

• [17][18], we investigated the ion transport activity of 1 and 2a across lipid bilayer membranes. In this study, the collapse of the pH gradient (pHout = 7.8 and pHin = 7.0), created across egg yolk ʟ-α-phosphatidylcholine (EYPC) vesicles with entrapped 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium

• interaction. However, the role of the neighboring amido groups cannot be ruled out. Moreover, the hydrophobic outer surface of the transporter helps the anion bound complex to permeate efficiently through the lipid bilayer membranes. Conclusion In conclusion, the intramolecular cyclization of linear di- and

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• molecules of water were randomly replaced by sodium ions. The system was minimized and equilibrated by series of restrained simulations (2.02 ns in total). Simulation of SERCA in a phospholipid bilayer In order to build a complex of SERCA protein with a phospholipid membrane, we used UCFS Chimera 1.10.2

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• vesicles, alone or in mixture with phospholipids, mimicking bacterial outer membrane vesicles (OMV) with potential antiadhesive properties. Keywords: glycolipids; outer membrane vesicles; synthetic vaccines; Introduction Outer membrane vesicles (OMV) [1], lipid bilayer vesicles released from the outer

• , Figure S4) [1]. This work suggests that mixtures of phospholipids such as POPC and small amounts of bioactive glycolipids should give a controlled bilayer. Such a construct could represent attractive carriers for vaccines once the sugar moiety of the glycolipid is substituted by Tn or Tf antigens [42][43

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• yields up to 91% (Scheme 4). Particularly interesting was the formation of DAG (18:0/20:4) 5d, an important lipidic backbone present in the biologically relevant phosphatidylinositol 4,5-bisphosphate (PIP2) [22]. In fact, diacylglycerols have proven to play vital roles in regulation of lipid bilayer and

Pd-Catalyzed microwave-assisted synthesis of phosphonated 13α-estrones as potential OATP2B1, 17β-HSD1 and/or STS inhibitors

• Rebeka Jójárt,
• Szabolcs Pécsy,
• György Keglevich,
• Mihály Szécsi,
• Réka Rigó,
• Csilla Özvegy-Laczka,
• Gábor Kecskeméti and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2018, 14, 2838–2845, doi:10.3762/bjoc.14.262

• phenolic hydroxy function. On the other hand, estrone sulfate is not able to cross the cell membrane passively; therefore, a carrier is needed to mediate its transport across the lipid bilayer. These carriers are certain representatives of the solute carrier superfamily (SLC), including members of the

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• B12 [30]. Indeed, in the crystal structure, 1 maintained the same corrin framework as natural B12 [31]. We combined the hydrophobic B12 derivatives with bilayer vesicles [32][33], a protein [34], organic polymers [35][36][37][38][39][40], and metal organic frameworks (MOFs) [41]. Furthermore, to

• carboxylic ester-migrated product was formed via not a radical, but a cationic intermediate that was generated by the fragmentation to the monoalkylated complex at the anode (Scheme 2). 2-2. Artificial enzyme-mediated reactions A vesicle-type B12 artificial enzyme was constructed by combining bilayer

Synergistic electrodeposition of bilayer films and analysis by Raman spectroscopy

• Saadeldin E. T. Elmasly,
• Luca Guerrini,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Neil J. Findlay,
• Karen Faulds and
• Peter J. Skabara

Beilstein J. Org. Chem. 2018, 14, 2186–2189, doi:10.3762/bjoc.14.191

• successfully demonstrated. Moreover, careful control of the electrochemical conditions allows the degree of doping to be effectively altered for one of the polymer layers. Raman spectroscopy confirmed the formation and doped states of the PEDOT/PEDTT bilayer. The electrochemical deposition of a bilayer

• ) raises the possibility of depositing a subsequent layer via solution-processing. Keywords: bilayer; electropolymerisation; PEDOT; PEDTT; Raman; Findings Fabrication of multilayer organic electronic devices has been extensively researched in the past 20 years, resulting in numerous processes and

• two different monomers in a step-wise fashion, a PEDOT/PEDTT bilayer was fabricated. Crucially, this approach provides an insoluble, conductive PEDOT layer, allowing the second PEDTT layer to be deposited on top (and subsequently de-doped), without compromising the initial deposition. Alemán and co

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

• Livia Polgár,
• Eszter Lajkó,
• Pál Soós,
• Orsolya Láng,
• Marilena Manea,
• Béla Merkely,
• Gábor Mező and
• László Kőhidai

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

• Ganna Gryn’ova and
• Clémence Corminboeuf

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

• Anja Gronewold,
• Mareike Horn and
• Ines Neundorf

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