Polyketide stereocontrol: a study in chemical biology

• Kira J. Weissman

Beilstein J. Org. Chem. 2017, 13, 348–371, doi:10.3762/bjoc.13.39

Posttranslational isoprenylation of tryptophan in bacteria

• Masahiro Okada,
• Tomotoshi Sugita and
• Ikuro Abe

Beilstein J. Org. Chem. 2017, 13, 338–346, doi:10.3762/bjoc.13.37

• -rich motif and the pseudo aspartate-rich motif in ComQ from seven Bacillus strains. Essential amino acid residues for function are shown in bold and colored blue. EcGGPPS is a geranylgeranyl diphosphate synthase derived from Escherichia coli ISC56. It’s essential amino acid residues for function are

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• relationship study. Ultimately, we wish to synthesize chemical probes of glorin for the identification of the unknown glorin receptor. Experimental Quantitative reverse transcription PCR: P. pallidum PN500 cells were cultured in association with Escherichia coli K12 cells. Cells were harvested before first

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• glycans in pathogens or parasites, numerous other lectins recognize such O-alkylated ligands, e.g., the pilus adhesin from Pseudomonas aeruginosa PAK [31] or PapG from Escherichia coli [32]. In contrast, methylation of lectin ligands can also prevent binding, as observed with O-methylated fucose and

Chemical probes for competitive profiling of the quorum sensing signal synthase PqsD of Pseudomonas aeruginosa

• Michaela Prothiwa,
• Dávid Szamosvári,
• Sandra Glasmacher and
• Thomas Böttcher

Beilstein J. Org. Chem. 2016, 12, 2784–2792, doi:10.3762/bjoc.12.277

• Escherichia coli BL21 followed by affinity purification by an ÄKTA chromatography system equipped with a StrepTrap HP column. The individual probes were incubated with purified PqsD for 30 min and a rhodamine fluorescent reporter tag was appended by click chemistry. The remaining non-covalently bound probe

Computational methods in drug discovery

• Sumudu P. Leelananda and
• Steffen Lindert

Beilstein J. Org. Chem. 2016, 12, 2694–2718, doi:10.3762/bjoc.12.267

• ][156]. Using BOMB it is possible to grow molecules by adding substituents into a core structure. It has been possible to design inhibitors for Escherichia coli RNS polymerase using the de novo drug design program SPROUTS [157]. In another study that used the SPROUT program, novel inhibitors were

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• triethylammonium phosphate in trichloroacetonitrile [30][31]. The gene encoding the 1,8-cineol synthase [28] was cloned into the yeast-to-Escherichia coli shuttle vector pYE-Express by homologous recombination in yeast [32], followed by expression in E. coli BL21. The protein was purified by Ni2+-NTA affinity

New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

• Ze’en Xiao,
• Senhua Chen,
• Runlin Cai,
• Shao’e Lin,
• Kui Hong and
• Zhigang She

Beilstein J. Org. Chem. 2016, 12, 2077–2085, doi:10.3762/bjoc.12.196

• epidermidis, Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis. None of the compounds was active at a concentration of 50 μg/mL. In the free radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH), only compounds 1 and 3 exhibited weak activity with EC50 values of 125 and 130 μM

Mechanistic investigations on six bacterial terpene cyclases

• Patrick Rabe,
• Thomas Schmitz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1839–1850, doi:10.3762/bjoc.12.173

• cloning by homologous recombination in yeast, followed by the heterologous expression in Escherichia coli, direct headspace sampling using a closed-loop stripping apparatus (CLSA) and compound identification by GC–MS [32][33]. Here we report on the purification of six of these bacterial sesquiterpene

Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

• Atul A. Dhavan,
• Rahul D. Kaduskar,
• Loana Musso,
• Leonardo Scaglioni,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2016, 12, 1624–1628, doi:10.3762/bjoc.12.159

• 17 in 50% yield. Compounds 1 and 17 were subjected to a preliminary study of the antimicrobial activity against Staphylococcus and Escherichia coli (Staphylococcus pseudintermedius [25], 25 strains; Escherichia coli, 20 strains. QC: S. aureus ATCC 25923 and Escherichia coli ATCC 25922 were also used

• , see Supporting Information File 1 for details). The MIC values of 1 against Staphylococcus pseudintermedius range at 16 µg/mL, while the values for 17 against Staphylococcus pseudintermedius are more variable and range between 32 and 64 µg/mL. The MIC of 1 and 17 against Escherichia coli range at 128

• pseudintermedius and Escherichia coli strains. Acknowledgments The authors gratefully acknowledge Professor L. Merlini for helpful suggestions and discussion.

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• properties. This expectation is supported by the biological activity of azomethine derivatives of pyrene-1-carboxaldehyde. They show antimicrobial action, e.g., 1-phenytoinylacetic acid hydrazone of pyrene-1-carboxaldehyde demonstrated a moderate antimicrobial activity towards Escherichia coli and

Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

• Lucian G. Bahrin,
• Henning Hopf,
• Peter G. Jones,
• Laura G. Sarbu,
• Cornelia Babii,
• Alina C. Mihai,
• Marius Stefan and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2016, 12, 1065–1071, doi:10.3762/bjoc.12.100

• different halogen substituents on the antibacterial properties has been tested against Staphylococcus aureus and Escherichia coli. Amongst the N,N-dialkylamino-substituted flavonoids, those having an N,N-diethylamino moiety exhibited good to excellent antimicrobial properties against both pathogens

• different halogen substituents of the A and B rings. This paper presents the results obtained, using this strategy against Staphylococcus aureus and Escherichia coli. Results and Discussion Chemistry The synthesis of the desired compounds was achieved using a method previously employed by us [14][15][16][17

• also established that dithiocarbamic flavanones of type 4 display no such activity. Therefore, only flavonoids 5a–m were tested against Staphylococus aureus (Gram positive) and Escherichia coli (Gram negative) in an attempt to establish an antimicrobial structure–activity relationship. Minimum

Marine-derived myxobacteria of the suborder Nannocystineae: An underexplored source of structurally intriguing and biologically active metabolites

• Antonio Dávila-Céspedes,
• Peter Hufendiek,
• Max Crüsemann,
• Till F. Schäberle and
• Gabriele M. König

Beilstein J. Org. Chem. 2016, 12, 969–984, doi:10.3762/bjoc.12.96

• marine myxobacteria are only slightly altered in terms of the addition of sea salt, when compared to those for terrestrial strains, e.g., terrestrial Escherichia coli is still used as prey. In addition, it surely is difficult to recognize marine myxobacterial colonies after isolation, since their

A cross-metathesis approach to novel pantothenamide derivatives

• Jinming Guan,
• Matthew Hachey,
• Lekha Puri,
• Vanessa Howieson,
• Kevin J. Saliba and
• Karine Auclair

Beilstein J. Org. Chem. 2016, 12, 963–968, doi:10.3762/bjoc.12.95

• activity. For example, what has now become the benchmark pantothenamide, N-pentylpantothenamide (1, Figure 1), is active against Escherichia coli [6] and Staphylococcus aureus [13], at minimum inhibitory concentrations (MICs) in the low micromolar range. Pantothenamides are however rapidly degraded by

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• oligosaccharide, selective solvolysis with CF3CO2H was employed. Recently, this method has been successfully used for the structure elucidation of the O-specific polysaccharides of Escherichia coli (e.g. [20]). The reagent was found to cleave selectively the glycosidic linkage of 6-deoxyhexoses (Rha, Fuc

Antibiotics from predatory bacteria

• Juliane Korp,
• María S. Vela Gurovic and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 594–607, doi:10.3762/bjoc.12.58

• in size and contain between 7,285 (Myxococcus fulvus HW-1) and 11,599 (Sorangium cellulosum So0157-2) protein-coding sequences (Table 1) [42][43][44][45][46][47]. In comparison, the genome of the standard laboratory bacterium Escherichia coli comprises only 4.6 Mbp of DNA [48]. With a single

• consumed the prey bacterium Bacillus subtilis, but not Escherichia coli. Further tests revealed that P. fallax HKI 727 exhibits a prey range that is restricted to Gram-positive bacteria. Culture extracts of strain HKI 727 showed a consistent antimicrobial profile, i.e., they were highly active against Gram

Effective in silico prediction of new oxazolidinone antibiotics: force field simulations of the antibiotic–ribosome complex supervised by experiment and electronic structure methods

• Jörg Grunenberg and
• Giuseppe Licari

Beilstein J. Org. Chem. 2016, 12, 415–428, doi:10.3762/bjoc.12.45

• flexibility of the U2620 (U2585 in Escherichia coli) moiety has already been discussed elsewhere [20]. Nevertheless, due to our simulation, there is no hydrogen bond between this nucleobase and the morpholine ring. The absence of a second hydrogen bond in our simulations (which is indeed observed for

• linezolid bound to the Deinococcus radiodurans 50S subunit) can be rationalized: the binding of linezolid into the ribosome stabilizes the position of U2620 (U2585 in Escherichia coli) in a slightly different (but decisive) orientation depending on the occupation of the A and P-site with tRNA ligands

• . Comparing our simulated bioactive conformation of linezolid with that from linezolid bound to Haloarcula marismortui (code 3CPW), we find a value of 0.70 RMSD, again pointing to the quality of our ribosomal model. Interestingly the nucleobase G2540 (U2505 in Escherichia coli) undergoes a profound

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• ), sodium dodecyl sulfate (SDS), thiazolyl blue (MTT), compounds for phosphate buffer saline (PBS) and lipopolysaccharides (LPS) from Escherichia coli O111:B4 were obtained from Sigma-Aldrich (Darmstadt, Germany). Dulbecco’s Modified Eagle’s Medium (DMEM) was obtained from Life Technologies (Carlsbad, CA

The marine sponge Agelas citrina as a source of the new pyrrole–imidazole alkaloids citrinamines A–D and N-methylagelongine

• Christine Cychon,
• Ellen Lichte and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2029–2037, doi:10.3762/bjoc.11.220

• cytotoxic activity. Classical agar diffusion assays were performed using the fungus Aspergillus niger, the yeast Saccharomyces cerevisiae as well as the Gram-negative bacterium Escherichia coli, and the Gram-positive bacterium Micrococcus luteus and Mycobacterium phlei as test organisms. In agar diffusion

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

• antimicrobial and cytotoxic lead structures. Cholesterol conjugate VI (Figure 1) arose from this consideration to be more active than ampicillin against the Gram-negative bacterial strain Escherichia coli (ATCC 11775) and the Gram-positive bacterial strain Staphylococcus aureus (ATTC 12600), while its

Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions

• Paul P. Kelly,
• Anja Eichler,
• Susanne Herter,
• David C. Kranz,
• Nicholas J. Turner and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2015, 11, 1713–1720, doi:10.3762/bjoc.11.186

• Escherichia coli (E. coli), variants of the fusion enzyme catalysed the efficient, highly selective hydroxylation of ionones without the need to supply expensive nicotinamide cofactors [20]. Given the previously demonstrated affinity of P450cam for hydrophobic substrates, we were interested to see if P450cam

SmI₂-mediated dimerization of indolylbutenones and synthesis of the myxobacterial natural product indiacen B

• Nils Marsch,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2015, 11, 1700–1706, doi:10.3762/bjoc.11.184

• natural product via X-ray analysis. Indiacen B (2) was tested against the Gram-positive bacteria Nocardioides simplex (1.7 µg/mL), Mycobacterium diernhoferi (no inhibition), and Mycobacterium sp. (8.3 µg/mL), and against the Gram-negative bacteria Escherichia coli TOL C (8.3 µg/mL), Chromobacterium

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• of Trichophyton mentagrophytes (MIC 6.2 µg/mL) and Epidermophyton floccosum (MIC 1.6 µg/mL) [87]. Though no activity was observed against the gram negative bacteria Escherichia coli and Pseudomonas aeruginosa, meridine (56) significantly inhibited the growth of the gram positive bacteria Bacillus

• negative Escherichia coli and the gram positive Micrococcus luteus bacteria [56]. Interestingly, the 9H-quinolino[4,3,2-de][1,10]phenanthrolin-9-one core corresponding to the ascididemin (42) structure once again has proved to be a suitable antibacterial pharmacophore (Figure 17) [56]. The decrease in the

N-Alkyl derivatives of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside; synthesis and antimicrobial activity

• Agata Walczewska,
• Daria Grzywacz,
• Dorota Bednarczyk,
• Małgorzata Dawgul,
• Andrzej Nowacki,
• Wojciech Kamysz,
• Beata Liberek and
• Henryk Myszka

Beilstein J. Org. Chem. 2015, 11, 869–874, doi:10.3762/bjoc.11.97

• inhibitory activity against the Gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa. In contrast, almost all the tested N-alkyl saponins were found to inhibit the growth of the Gram-positive bacteria (Table 2). Among the

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• rb [6]. In natural environments, hydrodynamic effects may cause forces competing with biomolecular interactions, such as the leukocyte adhesion to endothelial cells [7] or the Escherichia coli adhesion to uroepithelium cells [8]. The latter has been well analyzed by single-molecule force spectroscopy

• Wollschläger et al. successfully detected a different binding of DNA to the corresponding domain in the transcription factor PhoB from Escherichia coli for the wild-type and slightly modified mutants [23]. Utilizing the sequential unzipping of transmembrane proteins, a full mechanical mapping was possible for