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

• complexation. In that way, it was possible to decorate CDVs with carbohydrates [32][33], with peptides [34], and also with DNA [35]. Moreover CDVs were also shown to form very dense membranes in combination with phospholipids and cholesterol [36]. Previous studies also showed promising results for PDT

• 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

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• for divalent cations. It is commonly used to both modify intracellular Ca2+ concentrations and to investigate Ca2+ transport across biological membranes [58]. In 2011, Kocienski and co-workers reported on a formal synthesis of ionomycin using an auxiliary-directed, diastereoselective permanganate

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• membranes, cholesterol (Ch) is the most important lipidic building block. It is required for permeability, fluidity, and integrity of all animal cell membranes. However, as an unsaturated lipid, Ch is susceptible to oxidative degradation, which can result in potentially pathologic consequences encompassing

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• the PNPT superfamily. MraYAA crystallised as a dimer and additional experiments showed that it also exists as a dimer in detergent micelles and membranes [71]. The previously proposed models are in agreement with the solved structure showing ten transmembrane helices and five cytoplasmic loops. The

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• Supramolecular Chemistry was through the self-assembly of phospholipid membranes to form vesicles for which we were developing unimolecular and self-assembling transporter molecules. The next stage of my development as a scientist was in Japan with Seiji Shinkai where in a “Eureka” moment, the boronic acid

• least knowing how to) good research – summing up in Tom’s own words this was the “take home message from my PhD.” During my PhD we developed both self-assembling supramolecular pore formers as well as unimolecular ion channels for the transport of metal ions across biological membranes. The project

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

• strongly disrupt bacterial membranes, and a series of persubstituted γ-CD derivatives bearing polyamino groups (77% yield) [55]. MW-promoted Cu-catalyzed click reaction for the preparation of second generation CD derivatives and hybrid structures The MW-promoted CuAAC between CD monoazides and acetylenic

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• molecules may compromise their activity as poor distribution or passive diffusion across cell membranes are the usual drawbacks associated with their use. Developed after World War II, organophosphorus compounds were used as antitumor [1][2][3][4][5][6][7][8], antiviral [9][10][11][12], antihypertensive [13

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• conditions. Two fully independent long MD runs of increasingly large systems comprising up to sixty-four molecules suggest the presence of large-scale two-dimensional structures at length scales of more than 10 nm, comprising either relatively uniform membranes or a nano- and mesoporous mesh. Dynamic light

Bright molecules for sensing, computing and imaging: a tale of two once-troubled cities

• A. Prasanna de Silva

Beilstein J. Org. Chem. 2015, 11, 2774–2784, doi:10.3762/bjoc.11.298

• -nanometric environments such as those bounding membranes where concentrations of species like H+ can be radically different to what is found in the bulk water [48][49]. Since membrane-bounded H+ forms the heart of the field of bioenergetics [50], these concentrations need to be located as a function of

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• aqueous media to evaluate them as luminescent markers of biological molecules. The production of metal-cation-based anion exchange membranes from ROMP polymers was first reported by Tew et al. [57]. The ROMP reaction, induced here by the Grubbs 2nd generation catalyst, implied the copolymerization of a

• membranes provided with single cation–anion pairs. Cross-linking with dicyclopentadiene ensured a high mechanical stability of the copolymer. The film cast from 28 displayed an anion conductivity and mechanical properties similar to those of the traditional quaternary ammonium-based anion exchange membranes

Synthesis of cyclic N¹-pentylinosine phosphate, a new structurally reduced cADPR analogue with calcium-mobilizing activity on PC12 cells

• Ahmed Mahal,
• Stefano D’Errico,
• Nicola Borbone,
• Brunella Pinto,
• Agnese Secondo,
• Valeria Costantino,
• Valentina Tedeschi,
• Giorgia Oliviero,
• Vincenzo Piccialli and
• Gennaro Piccialli

Beilstein J. Org. Chem. 2015, 11, 2689–2695, doi:10.3762/bjoc.11.289

• analogues 3 and 4 retained the ability to pass the plasma membrane of neuronal cells. Conclusion cADPR is a second messenger synthesized by neuronal cells that modulates the Ca2+ homeostasis in the nervous system [42]. Unfortunately, cADPR is characterized by a low ability to cross the plasma membranes

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

• develop a series of mobile carriers for chloride ions across liposome and cell membranes [6]. There continues to be a strong community interest in chloride transporters as they are expected to exhibit interesting biological activity [7]. In addition, my group developed some of the first synthetic

• molecules to promote flip-flop of phospholipids across cell membranes, and thus alter the membrane structure and function. In particular, we discovered compounds that can scramble the transmembrane distribution of phosphatidylserine, a crucial signaling phospholipid. The synthetic scramblases make

• 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

• Giuseppina Raffaini,
• Antonino Mazzaglia and
• Fabio Ganazzoli

Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267

• molecules or by dispersion interactions at their lateral surface. We suggest that these aggregates can also form the nucleation stage of larger systems as well as the building blocks of micelles, vesicle, membranes, or generally nanoparticles thus opening new perspectives in the design of aggregates

• concentration and on the solvent) and by their shape, which may preferentially determine stable mesophases, ranging from micelles to membranes, or even liquid crystals. It is well-known that the shape and the interactions among native or modified cyclodextrins can drive specific packing in the solid state, but

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

• effects of CyDs in NPC cells are as follows; 1) CyDs may extract the free form of cholesterol from plasma membranes of lipid rafts, and then cholesterol in endolysosomes are transported to plasma membrane to supply, 2) the endocytosed CyDs may transport cholesterol from endolysosomes, and 3) the

• endocytosed CyDs may elicit a perturbation in endolysosomes membranes through the interaction with membrane components, which would result in the efflux of cholesterol from endolysosomes. In our preliminary study, 1 mM Lac-β-CyD could not extract cholesterol from the plasma membrane of U18666A-treated HepG2

• cells within 24 h (data not shown). Therefore, the lowering effects of Lac-β-CyD can be hardly explained by the cholesterol extraction ability from plasma membranes. Recently, Rosenbaum et al. revealed that CyD accelerated the cholesterol trafficking through modulation of the endocytic system, leading

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• ) is an amphiphilic-like steroidal constituent of eukaryotic cell membranes. It acts as fluidity buffer and it is essential for membrane integrity and permeability. Besides, it is a substrate for the biosynthesis of steroidal hormones, bile acids and vitamin D. Pathological accumulation of oxygenated

• cholesterol (oxysterol) metabolites contributes to the prognosis of major chronic diseases. Cholesterol is completely absent in prokaryotic organisms [1][2][3]. Cholesterol gives eukaryotic membranes sufficient mechanical stiffness against cationic selective antimicrobials (CSAs) such as antimicrobial

• 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

Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations

• Adriana K. Slavova-Kazakova,
• Silvia E. Angelova,
• Timur L. Veprintsev,
• Petko Denev,
• Davide Fabbri,
• Maria Antonietta Dettori,
• Maria Kratchanova,
• Vladimir V. Naumov,
• Aleksei V. Trofimov,
• Rostislav F. Vasil’ev,
• Giovanna Delogu and
• Vessela D. Kancheva

Beilstein J. Org. Chem. 2015, 11, 1398–1411, doi:10.3762/bjoc.11.151

• saponified extracts of maize bran and grasses [14]. Ferulic acid and the corresponding ethyl ester protect primary neuronal cell cultures against oxidative damage [14]. The increased lipophilicity of ferulic acid ethyl ester improves the ability to cross cell membranes easier than the corresponding acid. The

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

• complex nanoarchitectures [33][34], the interaction of such nanostructures with lipid membranes [35][36][37][38], as well as the optimization of the in vivo delivery of lipophilic siRNA [10][11][12] (e.g., by DNA trafficking [7]). Further studies from our group will include the binding of terminally

Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

• Katharina Koschek,
• Vedat Durmaz,
• Oxana Krylova,
• Marek Wieczorek,
• Shilpi Gupta,
• Martin Richter,
• Alexander Bujotzek,
• Christina Fischer,
• Rainer Haag,
• Christian Freund,
• Marcus Weber and
• Jörg Rademann

Beilstein J. Org. Chem. 2015, 11, 837–847, doi:10.3762/bjoc.11.93

• proteins flexibility is introduced by regions of inherent structural mobility, e.g., by so-called unstructured regions inserted between the receptor domains of a multireceptor protein. Alternatively, the relative mobility of binding sites is realized by their embedding into membranes giving them a certain

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

• of assemblies is most likely achieved by hydrogen bonds or other common receptor–binding interactions [28]. Although it is known that nanoparticles can be organised by binding to membranes by means of electrostatic interactions between the charged head group of the lipid and the oppositely charged

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

• those peptides to form large amyloid-like supramolecular assemblies. Second, in vivo, the large excess of cell surface membranes provides an unspecific target for the stearylated peptides. We show that acylated peptides insert into the lipid phase of such membranes. Eventually, our study reveals serious

• concentrations being in the range from 7 to 100 µM. It is important to note that the unspecific interaction of our compounds with cells can reduce the efficiency of compounds to prevent virus binding to cells, possibly even by incorporation into the lipid phase of membranes (see below). In addition to the human

• H5N1 at an MOI of 0.05 48 h post infection. Interaction with lipid membranes Although the above presented data may be promising in terms of efficient inhibition of influenza virus binding and, thus, infection, we have to take into account that the conditions of these experiments do not match the in

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• antiproliferative activity of these acylphloroglucinols in HMEC-1 increases with increasing log P. Increasing the number of carbon atoms in the acyl group provides higher lipophilicity, which allows the compound to better penetrate across cellular membranes in the in vitro assay. In contrast, the activity of the

• stability and the inability of the compound to cross cellular membranes [66]. To prevent oxidation and improve its bioavailability, modifications of EGCG focus on synthesizing more stable analogs (Figure 7). Anderson et al. [67] replaced the hydrolytically labile ester bond with a more stable amine and

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

• Hale Ünal,
• Naile Öztürk and
• Erem Bilensoy

Beilstein J. Org. Chem. 2015, 11, 204–212, doi:10.3762/bjoc.11.22

• biological membranes through positive surface charge. Nanocapsules were evaluated for their in vitro characteristics such as particle size, zeta potential, drug loading and release profiles followed by cell culture studies with the MCF-7 and Caco-2 cell line evaluating their anticancer efficacy and

• nanocapsules were then coated with the cationic polymer chitosan to improve the cellular uptake and interaction with biological membranes and penetration through intestinal mucosa for absorption of CPT and reaching the circulation. Nanocapsules were characterized for their in vitro properties followed by cell

• uptake. Therefore the particle size should be in an optimum range which enables particles to diffuse and permeate through the biological membranes, but also should provide the maximum ability for encapsulation of drugs and sustained release. The influence of CD concentration, concentration of oil phase

Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

• Martin Popr,
• Sergey K. Filippov,
• Nikolai Matushkin,
• Juraj Dian and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2015, 11, 192–199, doi:10.3762/bjoc.11.20

• acid [26]. Similar approaches of ionic self-assembly with CDs were used for the preparation of nanoparticles with external CD trigger [27], new material nanostructures [28], polyelectrolyte-surfactant complexes which yield new types of solid mesomorphous materials [29], or membranes with size-selective

Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

• Thorbjørn Terndrup Nielsen,
• Catherine Amiel,
• Laurent Duroux,
• Kim Lambertsen Larsen,
• Lars Wagner Städe,
• Reinhard Wimmer and
• Véronique Wintgens

Beilstein J. Org. Chem. 2015, 11, 147–154, doi:10.3762/bjoc.11.14

• drug permeability through biological membranes [9]. For instance, CDs and CD derivatives have been applied in both stabilization and solubility enhancement of CPT [10][11][12]. CD polymers are macromolecular structures bearing many CD moieties. This gives a number of advantages compared to native CDs