Multistep organic synthesis of modular photosystems

• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2012, 8, 897–904, doi:10.3762/bjoc.8.102

• NDI 18 of initiator 2, designed to initiate and template for SOSIP, was accessible from NDA 13 as well. The synthesis of NDI 19 by microwave-assisted imidation with Boc-protected lysine 20 has been reported before in the literature [15]. Reaction with Cbz-hydrazine gave the Cbz-protected NDI hydrazide

• diphosphonates in NDI 24 gave 18, which was reacted in situ with NDI 12 to yield initiator 2. Synthesis of propagators The synthesis of propagator 3 starts with NDA 13 as well (Scheme 2). Diimidation with Cbz-protected lysine 25 gave the diacid 26. Activation with EDC, HOBt and TEA was followed by the reaction

• naphthalenetetraesters (cNTEs). Nucleophilic core-substitution with ethanolate gave cNTE 34 as described in the literature [16]. NTE 34 was subjected to basic ester hydrolysis followed by diimidation with lysine 25. From this point, the synthesis of cNDI propagator 4 was analogous to the synthesis of NDI propagator 3

Synthetic glycopeptides and glycoproteins with applications in biological research

• Ulrika Westerlind

Beilstein J. Org. Chem. 2012, 8, 804–818, doi:10.3762/bjoc.8.90

• microbe and lectin binding studies, glycopeptide based glycoclusters/dendrimers were applied, employing linear peptide backbones, cyclic peptide scaffolds or multi-lysine scaffolds [106][107][108][109][110][111][112][113][114][115][116][117][118]. The pentavalent cholera toxin protein secreted by Vibrio

• further increased [137][138][139]. In one study, the FimH inhibition of mannosylated di- and tetravalent lysine core dendrimers resulted in 455- and 2000-fold increases relative to a monovalent mannose residue [114]. The observed multivalency effects are not fully understood. In a recent study, mannose di

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

• Raheleh Rezaei Araghi,
• Carsten C. Mahrenholz,
• Rudolf Volkmer and
• Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

• peptide (Acid-pp) and a lysine-rich chimeric B3β2γ sequence. These systems have a high propensity for heterooligomerization (Figure 1). In B3β2γ, the two central turns of the α-helix are substituted by a pentad of alternating β- and γ-amino acids. Our previous study revealed the heteromeric assembly of

Synthesis of heteroglycoclusters by using orthogonal chemoselective ligations

• Baptiste Thomas,
• Michele Fiore,
• Isabelle Bossu,
• Pascal Dumy and
• Olivier Renaudet

Beilstein J. Org. Chem. 2012, 8, 421–427, doi:10.3762/bjoc.8.47

• ., (CH2)4) of the lysine (Lys) and the norleucine (Nle) side chain. Synthesis of heteroglycoclusters of the 3:1 series. Reagents and conditions: (i) 1a, 2a or 3a, 0.1% TFA in H2O; (ii) 1b, 2b or 3b, Cu micropowder, t-BuOH, AcONH4 100 mM pH 7.4 (1:1, v/v). Outcome of the orthogonal ligation procedure

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• inhibit proteases. A signature of the group is the conserved ureido linkage connecting the side-chain amino acid to D-lysine. The corresponding NRPS gene cluster was first analyzed in the strain Anabaena sp. 90 and revealed a new mechanism underlying production of diverse variants by the same strain: Two

• /MvdD) and one ω-amide linkage between lysine and aspartate (MdnB/MvdC) (Figure 10) [64][65]. Microviridins can be heterologously produced in E. coli [65]. Cyclizations occur in a strictly defined order. Ring size and composition of the microviridin core peptide is invariant [66], whereas N-terminal and

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• grafted as terminal groups on to dendrimers. In particular the dansyl group has been frequently used to functionalize poly(propyleneimine) [7][8], poly(lysine) [9], poly(amidoamine) [10], and poly(melamine) [11] dendrimers. It has been shown that no interaction occurs between these terminal fluorophores

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• Wang-Yong Yang Samantha A. Marrone Nalisha Minors Diego A. R. Zorio Igor V. Alabugin Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA 10.3762/bjoc.7.93 Abstract Hybrid molecules combining photoactivated aryl acetylenes and a dicationic lysine

• the kinetics of photoinduced electron transfer (PET). The three analogous isomeric lysine conjugates cleaved DNA with different efficiencies (34, 15, and 0% of ds DNA cleavage for p-, m-, and o-substituted lysine conjugates, respectively) consistent with the alkylating ability of the respective

• acetamides. The significant protecting effect of the hydroxyl radical and singlet oxygen scavengers to DNA cleavage was shown only with m-lysine conjugate. All three isomeric lysine conjugates inhibited human melanoma cell growth under photoactivation: The p-conjugate had the lowest CC50 (50% cell

The allylic chalcogen effect in olefin metathesis

• Yuya A. Lin and
• Benjamin G. Davis

Beilstein J. Org. Chem. 2010, 6, 1219–1228, doi:10.3762/bjoc.6.140

• GlcNAc, mannose and N-acetylamine, which could serve as effective mimics of post-translational protein modifications (glycosylation, lysine acetylation). Conclusion Since the early work by Hoye on secondary allylic alcohols [19] and later the studies on allyl sulfides by our group [17], the allyl

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

• and amount of the monomers used, and could be re-dispersed in water after removal of the solvent for release studies. Ethylene glycol diglycidyl ether and L-lysine were polymerized via interfacial polyaddition in inverse miniemulsion [100]. The particles were found to be amphoteric and bear positive

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• ), compared to commercially available magnetic particles for the protein binding with reported capacities between 1.5 mg·g−1 and 20 mg·g−1 [33][56]. The catalytic activity of trypsin, a protease for hydrolysis of specific peptide bonds (chain scission after the amino acids arginine and lysine), is

RAFT polymers for protein recognition

• Alan F. Tominey,
• Julia Liese,
• Sun Wei,
• Klaus Kowski,
• Thomas Schrader and
• Arno Kraft

Beilstein J. Org. Chem. 2010, 6, No. 66, doi:10.3762/bjoc.6.66

• 5, 45117 Essen, Germany 10.3762/bjoc.6.66 Abstract A new family of linear polymers with pronounced affinity for arginine- and lysine-rich proteins has been created. To this end, N-isopropylacrylamide (NIPAM) was copolymerized in water with a binding monomer and a hydrophobic comonomer using a

• -soluble trithiocarbonate 8 [13][14] which efficiently caps the growing polymer chain, but can be completely removed from the final polymer by reaction with an excess of AIBN and selective polymer precipitation into hexane [11]. Three anionic comonomers suitable for binding lysine and arginine were chosen

• could be detected for the short version, indicating that size matters and promotes multivalent or cooperative binding. Finally, the protein series was extended to lysine-rich histone (pI 10), lysozyme (pI 9), proteinase K (pI 8) and bovine serum albumin or BSA (pI 6). Again, the strong binders B20CH15

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

Synthesis of lipophilic 1-deoxygalactonojirimycin derivatives as D-galactosidase inhibitors

• Georg Schitter,
• Elisabeth Scheucher,
• Andreas J. Steiner,
• Arnold E. Stütz,
• Martin Thonhofer,
• Chris A. Tarling,
• Stephen G. Withers,
• Jacqueline Wicki,
• Katrin Fantur,
• Eduard Paschke,
• Don J. Mahuran,
• Brigitte A. Rigat,
• Michael Tropak and
• Tanja M. Wrodnigg

Beilstein J. Org. Chem. 2010, 6, No. 21, doi:10.3762/bjoc.6.21

• neurological deterioration [23]. Our studies revealed that 1-deoxy-D-galactonojirimycin-lysine hybrids, when carrying an aromatic substituent, such as a dansyl moiety, in its nature a lipophilic aromatic substituent, are potent D-galactosidase inhibitors and also show activity with human lysosomal β

The first preparative solution phase synthesis of melanotan II

• Vladimir V. Ryakhovsky,
• Georgy A. Khachiyan,
• Nina F. Kosovova,
• Elena F. Isamiddinova and
• Andrey S. Ivanov

Beilstein J. Org. Chem. 2008, 4, No. 39, doi:10.3762/bjoc.4.39

• stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2)+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the ε-amino group of lysine and

• locking of the linear peptide sequence in its biologically active conformation by lactamization of the lysine ε-amino group and glutamic acid γ-carboxy group, led to a cyclic pseudopeptide analog of α-MSH with good metabolic stability and exceptional activity, known as melanotan II (2) (Figure 1). Results

• groups. The ε-amino group of lysine and the γ-carboxy group of aspartic acid, involved in lactamization, were protected as the base-cleavable Fmoc amide and Fm ester respectively. After synthesizing the peptide chain and cleavage of the base-labile protecting groups, an efficient on-resin cyclization was