Synthesis, characterization and DNA interaction studies of new triptycene derivatives

• Sourav Chakraborty,
• Snehasish Mondal,
• Rina Kumari,
• Sourav Bhowmick,
• Prolay Das and
• Neeladri Das

Beilstein J. Org. Chem. 2014, 10, 1290–1298, doi:10.3762/bjoc.10.130

• functionalities) with DNA. According to a literature survey, many metal-free small molecules are known to modify structural organization of DNA through recognition, binding, cleavage or crosslinking and reportedly have widespread applications in biology [26]. Targeting of DNA by several DNA-damaging agents have

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

• can be divided in two broad categories depending on the presence of polymerizable groups. When polymerizable groups are present, the fire-resistant molecule can be included in polymers by copolymerization or can act as a crosslinking agent. This type of compounds is also employed for the surface

Physalin H from Solanum nigrum as an Hh signaling inhibitor blocks GLI1–DNA-complex formation

• Midori A. Arai,
• Kyoko Uchida,
• Samir K. Sadhu,
• Firoj Ahmed and
• Masami Ishibashi

Beilstein J. Org. Chem. 2014, 10, 134–140, doi:10.3762/bjoc.10.10

• crosslinking by UV transilluminator (312 nm, 15 min), biotin-labeled DNA was detected by HRP-conjugated streptavidin, following the manufactures’ protocols. Schematic procedure of the constructed assay system; Tc (tetracycline), TetR (tetracycline repressor), TetO (tetracycline operator). Isolated compounds

N,N'-(Hexane-1,6-diyl)bis(4-methyl-N-(oxiran-2-ylmethyl)benzenesulfonamide): Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

• Julian Fischer,
• Simon Millan and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2834–2840, doi:10.3762/bjoc.9.318

• protons. Oscillatory rheological measurements of an equimolar mixture of 6 and 8 at 50 °C. Illustrated is the complex viscosity (A), as well as G’ and G’’ (B) in dependence of time. The polymer 9 is displayed as an idealized structure (R = H or polymer network; crosslinking via addition of epoxide

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

• Kimberley A. Roper,
• Malcolm B. Berry and
• Steven V. Ley

Beilstein J. Org. Chem. 2013, 9, 1781–1790, doi:10.3762/bjoc.9.207

• clearly viewed in a video previously released by our group [40], however the Ramirez monoliths employ a higher ratio of styrene to divinylbenzene. This results in a lower proportion of crosslinking within the monolith, allowing greater flexibility in the backbone of the polymer whilst still maintaining

Activation of cryptic metabolite production through gene disruption: Dimethyl furan-2,4-dicarboxylate produced by Streptomyces sahachiroi

• Dinesh Simkhada,
• Huitu Zhang,
• Shogo Mori,
• Howard Williams and
• Coran M. H. Watanabe

Beilstein J. Org. Chem. 2013, 9, 1768–1773, doi:10.3762/bjoc.9.205

• or cryptic metabolites for subsequent isolation and characterization. Secondary metabolite production by microorganisms is often viewed as a line of defense against competing microbes for nutrients. Natural products like azinomycin, a DNA crosslinking agent, can offer a means of protection to the

Glycosylation efficiencies on different solid supports using a hydrogenolysis-labile linker

• Mayeul Collot,
• Steffen Eller,
• Markus Weishaupt and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 97–105, doi:10.3762/bjoc.9.13

• hydrolysis or enzymatic reactions. There are different variations of pure polystyrene resins. Jandajel resin for example features crosslinking of PS chains by tetrahydrofuran derivatives [29][30]. To improve the swelling behavior of PS resins in polar solvents, the PS core was grafted with polyethylene

Supramolecular hydrogels formed from poly(viologen) cross-linked with cyclodextrin dimers and their physical properties

• Yoshinori Takashima,
• Yang Yuting,
• Miyuki Otsubo,
• Hiroyasu Yamaguchi and
• Akira Harada

Beilstein J. Org. Chem. 2012, 8, 1594–1600, doi:10.3762/bjoc.8.182

• the C10 unit of VP and the α-CD unit of the α,α-CD dimer is important for the formation of cross-links between VPs (Figure 3). The cavity size of β-CD is too large to allow formation of a stable cross-linked polyrotaxane complex. The α,β-CD dimer and β,β-CD dimer do not function as crosslinking

• molecules between VP and β-CD. Actually, the association constant of α-CD with decamethylene is much higher than that of β-CD with decamethylene [24]. Consequently, the association constant plays an important role in gel formation. To confirm a supramolecular hydrogel formed by crosslinking VP with the α,α

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• polymerization of the azocompound 23 (monomer), by using the diacrylate derivative 24 as a crosslinking agent. The azo-LCEs comprise a polydomain with the characteristics of a liquid crystal, formed by many microsized domains of azobenzene aligned in the same direction. Although macroscopically the direction of

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

• Branislav Husár,
• Norbert Moszner and
• Ivan Lukáč

Beilstein J. Org. Chem. 2012, 8, 337–343, doi:10.3762/bjoc.8.37

• formed in irradiated films of styrene copolymers with pendant BZ groups leads to crosslinking, only small molecular-weight changes in irradiated MCQ/S were observed. Keywords: camphorquinone; 1,2-diketone; (±)-10-methacryloyloxycamphorquinone; photooxidation; polystyrene; Introduction Camphorquinone

• most probably also present in the photooxidized MCQ/S copolymer. Whereas the previously published irradiation of styrene copolymers with the monomers containing BZ (Mn = 84000, PD = 1.8) with 0.54 mol % of the BZ-containing component led to extensive crosslinking with 69% gel fraction [21], MCQ/S with

• copolymer (Mn = 190000, PD = 2.7) were higher than those of the initial copolymer (Mn = 170000, PD = 2.0). Therefore, some recombination of macroradicals occurred during irradiation. However, the crosslinking of styrene copolymers with the monomers containing BZ is significantly more efficient than those of

Exceptionally small supramolecular hydrogelators based on aromatic–aromatic interactions

• Junfeng Shi,
• Yuan Gao,
• Zhimou Yang and
• Bing Xu

Beilstein J. Org. Chem. 2011, 7, 167–172, doi:10.3762/bjoc.7.23

• strain. The G’ remained almost constant when the strain increased and then suddenly decreased, indicating the loss of crosslinking within the gel network. Obviously, the critical strain of gel IV is greater than the others. These results suggest that gel IV can form a more complex network structure

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• yielded only irregular structures due to inadequate crosslinking. PEG-b-PPG-b-PEG was used in combination with the organometallic surfactant to reduce the concentration of the latter surfactant on the droplet surface [136]. When 20 wt % toluene was used with low concentration of the organometallic

En route to photoaffinity labeling of the bacterial lectin FimH

• Thisbe K. Lindhorst,
• Michaela Märten,
• Andreas Fuchs and
• Stefan D. Knight

Beilstein J. Org. Chem. 2010, 6, 810–822, doi:10.3762/bjoc.6.91

• appropriate methodology in this endeavour and hence biotin-labeled photoactive mannosides were designed and synthesized for photoaffinity labeling of FimH. So far, the photo-crosslinking properties of the new photoactive mannosides could be detailed with the peptide angiotensin II and labeling of FimH was

• two steps gave the Fmoc-protected biotin-labeled glycoamino acids 9 and 10, respectively. Fmoc-cleavage and peptide coupling with the diazirine 11 led to the target molecules 12 and 13 in good yield. To test the prepared photoactive mannosides in crosslinking reactions, the model peptide angiotensin

• unequivocally shown that insertion of the carbene, which results after irradiation of 2, occurs at the hydroxyl group in the side chain of the angiotensin tyrosine (Y) (see Experimental Part). This crosslinking reaction leads to the ether 14 (Scheme 2). Analogously, the photo-crosslinked products, obtained from

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• crosslinking dimethacrylates, such as 2,2-bis[(4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (Bis-GMA) or triethylene glycol dimethacrylate (TEGDMA) [1]. In SEAs, water is primarily used as the solvent or co-solvent. Thus, especially in the case of one-bottle adhesives, the methacrylates may undergo

Shape- persistent macrocycle with intraannular alkyl groups: some structural limits of discotic liquid crystals with an inverted structure

• Sigurd Höger,
• Jill Weber,
• Andreas Leppert and
• Volker Enkelmann

Beilstein J. Org. Chem. 2008, 4, No. 1, doi:10.1186/1860-5397-4-1

• are also not bulky enough to extend into the interior of neighbored rings. Therefore, a physical crosslinking of the molecules, as it was supposed to be responsible for the absence of a mesophase in other shape-persistent rings, can be excluded. However, different to the previously investigated