An efficient synthesis of 1,6-anhydro-N-acetylmuramic acid from N-acetylglucosamine

• Matthew B. Calvert,
• Christoph Mayer and
• Alexander Titz

Beilstein J. Org. Chem. 2017, 13, 2631–2636, doi:10.3762/bjoc.13.261

• in only five steps from the cheap starting material N-acetylglucosamine. This efficient synthesis should enable future studies into the importance of 1,6-anhydromuramic acid in bacterial cell wall recycling processes. Keywords: N-acetylmuramic acid; anhydrosugars; antibiotic resistance; bacterial

• cell wall recycling; carbohydrate synthesis; Introduction 1,6-Anhydro-N-acetylmuramic acid (AnhydroMurNAc, 1, Figure 1) and its derivatives (e.g., 2 and 3) are of great interest due to their integral role in bacterial cell wall recycling [1][2] and the induction of antibacterial resistance [3

Sulfation and amidinohydrolysis in the biosynthesis of giant linear polyenes

• Hui Hong,
• Markiyan Samborskyy,
• Katsiaryna Usachova,
• Katharina Schnatz and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2017, 13, 2408–2415, doi:10.3762/bjoc.13.238

• . Sulfonation has been suggested as a novel approach to block the development of antibiotic resistance [33][34] while the discovery of the sulfated metabolite FR901379 was a critical breakthrough in the successful clinical development of micafungin to combat systemic fungal infections [12]. HPLC–UV–MS analysis

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• is small [21][22]. As a result, compounds into which fluorine has been introduced may show beneficial changes in their properties. In addition, among the chemical bonds formed by carbon, fluorine bonds have the highest binding energy [23], such that fluorine-containing compounds often show resistance

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• anhydrase [37] or during the hydrolysis of amide [38]. The main difference between phosphate and phosphonic acid arises from the higher stability (resistance towards enzymatic degradation) of the P–C bond when compared to the P–O bond present in phosphate. Accordingly, phosphonic acid was used for numerous

1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides

• Fei-Fei Xu,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2017, 13, 1994–1998, doi:10.3762/bjoc.13.195

• , including dichloromethane, is sold under the trade name Brom-55 and used as swimming pool sanitizer, as industrial brominating agent for ethylene propylene diene monomer rubber to improve ozone resistance, as additive in plastics to promote photodegradation and as a fungicide to preserve fresh fruits [27

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• energy is needed to overcome the lattice energy and melt the salt. Ion liquids are also called “green solvents”, because of their low vapor pressure, fire resistance and thermal stability [4]. Beside this, they have a high ionic conductivity, large heat capacity and good thermal and chemical stability [5

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• infections and drug resistant pathogens, and the increased use of implantable and indwelling medical devices. Much research is now focusing on developing materials that resist bacterial attachment and growth as an alternative to new antibacterial agents to which the development of resistance is inevitable

Total syntheses of the archazolids: an emerging class of novel anticancer drugs

• Stephan Scheeff and
• Dirk Menche

Beilstein J. Org. Chem. 2017, 13, 1085–1098, doi:10.3762/bjoc.13.108

• inhibition of V-ATPase abrogates tumor metastasis via repression of endocytic activation [28], leads to impaired cathepsin B activation in vivo [30], modulates anoikis resistance and metastasis of cancer cells [31], overcomes trastuzumab resistance of breast cancers [32], blocks iron metabolism and thereby

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

• Maryna V. Murlykina,
• Maryna N. Kornet,
• Sergey M. Desenko,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Aleksander A. Brazhko,
• Vladimir I. Musatov,
• Erik V. Van der Eycken and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

• of diseases. However, we are still facing the problem of untreated ones, together with the appearance of unknown disorders and the dramatical growth of antimicrobial resistance caused by the continuous evolution of microorganisms [1][2][3][4][5]. Therefore, there is urgency in careful screening the

• resistance to almost all the compounds tested in the given concentration range. The strain of B. subtilis was found to be sensitive to compounds 4i and 6d, but the bacteriostatic activity was fixed only in the highest concentration 500 mg/L. The information about the influence of the compounds on bacteria is

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• -antibiotic conjugates, were prepared and resulted able to overcome antibiotic resistance of microbial biofilms, since CA NPs render streptomycin more accessible to biofilms, thereby more available to interact with biofilm bacteria [89]. Similarly, a novel recyclable E.coli-specific killing GAuNP

Use of costic acid, a natural extract from Dittrichia viscosa, for the control of Varroa destructor, a parasite of the European honey bee

• Kalliopi Sofou,
• Demosthenis Isaakidis,
• Apostolos Spyros,
• Anita Büttner,
• Athanassios Giannis and
• Haralambos E. Katerinopoulos

Beilstein J. Org. Chem. 2017, 13, 952–959, doi:10.3762/bjoc.13.96

• ]. Literature data indicated that a number of pesticide residues have been detected in honey samples [11][12]. Given that the parasite has developed significant resistance to synthetic acaricides, alternatives such as oxalic acid [13][14][15] were proposed and extensively studied for their effects against

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• orbitals of polymer P2. Both the HOMO and LUMO levels of the polymer have decreased energy as compared to polymer P1 (from −5.48 eV to −5.53 eV and from −3.58 eV to −3.75 eV, respectively). This reduction of the HOMO energy level improves the resistance towards oxidative degradation of the material. Also

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• issues owing to many potential side reactions, particularly in relation to chemoselectivity, i.e., over-hydrogenation of alkenes to alkanes [44][45], resistance of other functional groups (ketones [46][47], amines [48][49], azides [50]), regioselectivity [51][52] , isomerization [53][54] and

• ]; the strong metal–support interactions, particularly for inorganic oxide materials, e.g., TiO2 [94][95]. Besides contributing to catalyst resistance by hampering the loss and the size increase of active sites, MNP stabilization is a key factor to limit the amount of metal leached in solution, an issue

• selectivity issues, need of toxic additives, high metal loadings and limited catalyst resistance. Ever increasing environmental and economic constraints have boosted the development of innovative catalytic materials and processes with improved performance and lower environmental impact. Great advancements

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• ]. Singlet oxygen offers important advantages over conventional drugs as it: i) potentially attacks biological substrates of different nature (i.e., lipids, proteins, and DNA), ii) does not suffer from multidrug resistance (MDR) problems, and iii) due to its short half-life (<0.1 ms) and lack of charge, it

NMR reaction monitoring in flow synthesis

• M. Victoria Gomez and
• Antonio de la Hoz

Beilstein J. Org. Chem. 2017, 13, 285–300, doi:10.3762/bjoc.13.31

• : Excellent B1-field uniformity and B1/i field efficiency resulting in a high signal-to-noise ratio (SNR). In comparison to planar coils, the solenoid have lower resistance, better nutation curves (reaching the ideal sinusoidal behaviour) representing a much more uniform B1 field than planar coils, however

• planar coils are: Planar coils suffer of a high series resistance resulting in a low SNR as the latter is dominated by the thermal noise of the coil. The SNR depends on the geometrical features of the coil. For instance, the number of turns is crucial since a large number of turns can increase the

• unitary field produced by the coil but will also lead to higher resistance [21]. It is believed that the nearby windings of the coil induce static field distortions resulting in lower resolution and sensitivity in the NMR spectrum [22]. The optimum dimensions for a planar microcoil were presented by van

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• 10.3762/bjoc.12.226 Abstract Rising resistance to current clinical antibacterial agents is an imminent threat to global public health and highlights the demand for new lead compounds for drug discovery. One such potential lead compound, the peptide antibiotic teixobactin, was recently isolated from an

• uncultured bacterial source, and demonstrates remarkably high potency against a wide range of resistant pathogens without apparent development of resistance. A rare amino acid residue component of teixobactin, enduracididine, is only known to occur in a small number of natural products that also possess

• encountered to date in the development of efficient synthetic routes to facilitate drug discovery efforts inspired by the discovery of teixobactin. Keywords: amino acid; bacterial resistance; enduracididine; natural products; peptide antibiotics; Review Introduction The enduracididines The enduracididines

Evidence for an iterative module in chain elongation on the azalomycin polyketide synthase

• Hui Hong,
• Yuhui Sun,
• Yongjun Zhou,
• Emily Stephens,
• Markiyan Samborskyy and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2016, 12, 2164–2172, doi:10.3762/bjoc.12.206

• from a BAC library of S. malaysiensis DSM4137 genomic DNA as described in Supporting Information File 1, and named pYJ2. To allow the introduction of the cloned azl cluster into actinomycete host strains that are intrinsically resistant to thiostrepton (tsr), the tsr resistance cassette of pYJ2 was

• replaced by the apramycin resistance cassette aac(3)IV [57] using RedET recombineering of pYJ2 in E. coli to generate BAC clone pML1. Tri-parental mating was used [58] to introduce pML1 into E. coli ET12567, a triply methylation-deficient strain that provides higher efficiency of conjugation into many

• strain was used for conjugation with S. lividans. Selection for apramycin resistance led to the isolation of exconjugants, four of which were analysed using PCR with two flanking and twelve internal PCR primer pairs. Two colonies were found which appeared to contain the full azl gene cluster while the

Diastereoselective synthesis of 3,4-dihydro-2H-pyran-4-carboxamides through an unusual regiospecific quasi-hydrolysis of a cyano group

• Mikhail Yu. Ievlev,
• Oleg V. Ershov,
• Mikhail Yu. Belikov,
• Angelina G. Milovidova,
• Viktor A. Tafeenko and
• Oleg E. Nasakin

Beilstein J. Org. Chem. 2016, 12, 2093–2098, doi:10.3762/bjoc.12.198

• the path of transformations without the participation of water (Scheme 3, path II) as actual. Such an abnormal resistance of the imine moiety to be simply hydrolyzed in aqueous acidic media is very exciting. Therefore we attempted to use other acids to investigate the behavior of the imine moiety in

• exceptional diastereoselectivity based on the reaction of available 4-oxoalkane-1,1,2,2-tetracarbonitriles (adducts of TCNE and ketones) with aldehydes in acidic media. Unusual processes of regiospecific quasi-hydrolysis of a cyano group and abnormal resistance of the imine moiety to be hydrolyzed in aqueous

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• are suitable for most applications. A low dead volume and a high pressure resistance are key characteristics of T mixers. However, careful optimization of the internal size, shape, and dead volume of the T-mixer directly affects the local concentrations of the reagents and thus can have dramatic

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

• rearrangement of aliphatic hydroperoxides proceeds quite readily in concentrated H2SO4 [318] or superacids [319] (Scheme 52). This is associated with higher resistance of these compounds toward acid-catalyzed rearrangements compared with benzylic or allylic hydroperoxides. For example, aliphatic hydroperoxides

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

• Tai Nguyen Van,
• Audrey Hospital,
• Corinne Lionne,
• Lars P. Jordheim,
• Charles Dumontet,
• Christian Périgaud,
• Laurent Chaloin and
• Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

• their corresponding nucleosides [2][3]. Recent studies on patients affected by haematological malignancies, such as acute myeloid leukaemia (AML) and myelodysplasic syndrome (MS), have demonstrated the involvement of cN-II in the resistance to cytotoxic drugs such as mercaptopurines and suggested the

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• properties, QASs have many drawbacks. Their rapid spread in society and the increasing resistance of pathogenic microorganisms [16] require new chemicals, including QASs, posing new risks for the environment and the living organisms. However, the long-term effects of these new compounds with regard to their

Discovery of an inhibitor of the production of the Pseudomonas aeruginosa virulence factor pyocyanin in wild-type cells

• Bernardas Morkunas,
• Balint Gal,
• Warren R. J. D. Galloway,
• James T. Hodgkinson,
• Brett M. Ibbeson,
• Yaw Sing Tan,
• Martin Welch and
• David R. Spring

Beilstein J. Org. Chem. 2016, 12, 1428–1433, doi:10.3762/bjoc.12.137

• important opportunistic human pathogen [1]. This opportunistic pathogen is well known to be a challenging infection to completely eradicate in infected patients due to high levels of intrinsic resistance to a wide variety of antibiotics [1][2][3][4][5][6] and the tendency of P. aeruginosa cells to form

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• to P3HT. Dynamic impedance spectroscopy Dynamic impedance spectroscopy was used to determine the charge-transporting parameters in the PSCs, such as the chemical capacitance, recombination resistance, and charge conductivity [45]. It is known that the performance metrics of the HTMs in the PSCs can

• be partially explained by these parameters. For example, it was suggested that FF is associated with the series resistance (Rs), and a low Rs is required to construct high performance photovoltaic devices [46]. The dynamic impedance spectra of the PSCs with different HTMs over the frequency range of

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• /reductive elimination pathway shuttling the hydrogen atom from the nitrogen atom via the W atom to the carbene carbon atom. This pathway is unfeasible for homologous chromium complexes and explains the resistance of Cr(CO)5(E-2) towards thermal E-3 formation. A base-assisted pathway for imine formation is