A novel and widespread class of ketosynthase is responsible for the head-to-head condensation of two acyl moieties in bacterial pyrone biosynthesis

• Darko Kresovic,
• Florence Schempp,
• Zakaria Cheikh-Ali and
• Helge B. Bode

Beilstein J. Org. Chem. 2015, 11, 1412–1417, doi:10.3762/bjoc.11.152

• mechanism of pyrone formation has been investigated by amino acid exchange and bioinformatic analysis. Additionally, the evolutionary origin of PpyS has been studied by phylogenetic analyses also revealing homologous enzymes in Pseudomonas sp. GM30 responsible for the biosynthesis of pseudopyronines

• with OleA. As expected, the remaining 51 sequences show a higher similarity to PpyS and the newly formed PpyS branch shows a separation into two distinct groups with PpyS and PyrS (pseudopyronine synthase) being present in one of them. The homologue PyrS from Pseudomonas sp. GM30 is described below

• pyrone biosynthesis we analyzed the KS from Pseudomonas sp. GM30, as we knew that α-pyrone antibiotics pseudopyronine A (9) and B (10) have been isolated in two Pseudomonas strains but neither their biosynthesis nor the involved KS had been reported yet [28]. Both compounds have been described to show an

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

Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

• Zhi Kai Guo,
• Rong Wang,
• Wei Huang,
• Xiao Nian Li,
• Rong Jiang,
• Ren Xiang Tan and
• Hui Ming Ge

Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282

• avenae subsp. Citrulli, Erwinia amylovora, Pseudomonas syringae pv. Lachrymans, Clavibacter michiganense subsp. Sepedonicus, and Pectobacterium carotovorum subsp. carotovorum) and fungi (Rhizoctonia solani Kühn, Rhizotonia cerealis van der Hoeven, Phytophthora capsici Leonian, Fusarium moniliforme Sheld

• colorectal cancer, were evaluated with the MTT assay [16][17]. Antimicrobial activities against a variety of plant pathogenic bacteria (Xanthomonas oryzae pv. oryzae Swings, Xanthomonas oryzae pv. oryzicola Swings, Acidovorax avenae subsp. Citrulli, Erwinia amylovora, Pseudomonas syringae pv. Lachrymans

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• -hydroxybenzoate, benzyl alcohol, 2-phenoxyethanol) [45]. The authors established a clear relationship between the binding constants and the antimicrobial activity of the preservatives on various strains: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and C. albicans. Indeed, highly water-soluble

Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators

• Michail Syrpas,
• Ewout Ruysbergh,
• Christian V. Stevens,
• Norbert De Kimpe and
• Sven Mangelinckx

Beilstein J. Org. Chem. 2014, 10, 2539–2549, doi:10.3762/bjoc.10.265

• , inhibition of bacterial QS was recently demonstrated by a set of electrophilic probes (which included halogenated analogues of AHLs) that could covalently bind in the LasR binding pocket of Pseudomonas aeruginosa [15]. Therefore, designing analogues with small reactive moieties, such as halogenated carbon

Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation

• Meriem Smadhi,
• Sophie de Bentzmann,
• Anne Imberty,
• Marc Gingras,
• Raoudha Abderrahim and
• Peter G. Goekjian

Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206

• glycoclusters based on a triazine core bearing D-galactose and L-fucose epitopes are able to inhibit biofilm formation by Pseudomonas aeruginosa. These multivalent ligands are simple to synthesize, are highly soluble, and can be either homofunctional or heterofunctional. The galactose-decorated cluster shows

• good affinity for Pseudomonas aeruginosa lectin lecA. They are convenient biological probes for investigating the roles of lecA and lecB in biofilm formation. Keywords: antibiotic; biofilm; glycocluster; lectin; multivalency effect; multivalent glycosystems; Introduction Pseudomonas aeruginosa (PA

• . The 6-deoxymannose isostere 15 was not tested, in view of the low affinity of the β-fucose epitopes. These clusters thus represent a readily accessible, highly soluble, and convenient tool for the investigation of the role of lecA and lecB in the formation of biofilms by Pseudomonas aeruginosa

Synthesis and bioactivity of analogues of the marine antibiotic tropodithietic acid

• Patrick Rabe,
• Tim A. Klapschinski,
• Nelson L. Brock,
• Christian A. Citron,
• Paul D’Alvise,
• Lone Gram and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2014, 10, 1796–1801, doi:10.3762/bjoc.10.188

• previously reported from Pseudomonas [2][3]. The biosynthesis of 1 starts from phenylalanine and requires the paaABCDE and paaG genes of the upper phenylacetic acid (PAA) catabolon [4][5], the six genes tdaABCDEF that are located on a plasmid [6][7], and the adjacent paaZ2 gene [8], a mutated copy of paaZ

Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

• Silvia Bernardi,
• Paola Fezzardi,
• Gabriele Rispoli,
• Stefania E. Sestito,
• Francesco Peri,
• Francesco Sansone and
• Alessandro Casnati

Beilstein J. Org. Chem. 2014, 10, 1672–1680, doi:10.3762/bjoc.10.175

• efficient multivalent ligands for a series of pathological lectins. For instance, cholera toxin is bound rather efficiently by calix[4]arene [16] and calix[5]arene [17] derivatives, while examples of Pseudomonas aeruginosa LecB binding were reported with galactosylcalixarenes blocked in different

Synthesis and solvodynamic diameter measurements of closely related mannodendrimers for the study of multivalent carbohydrate–protein interactions

• Yoann M. Chabre,
• Alex Papadopoulos,
• Alexandre A. Arnold and
• René Roy

Beilstein J. Org. Chem. 2014, 10, 1524–1535, doi:10.3762/bjoc.10.157

• lectins such as ConA [43] and the LecA lectin from Pseudomonas aeruginosa [17]. With these closely related families of mannosylated dendrimers in hand, together with their known relative size in solution, we are now well positioned to evaluate their binding behavior against their cognate proteins and this

Efficient routes toward the synthesis of the D-rhamno-trisaccharide related to the A-band polysaccharide of Pseudomonas aeruginosa

• Aritra Chaudhury,
• Sajal K. Maity and
• Rina Ghosh

Beilstein J. Org. Chem. 2014, 10, 1488–1494, doi:10.3762/bjoc.10.153

• the A-band polysaccharide of Pseudomonas aeruginosa. One of the key steps involved 6-O-deoxygenation of either partially or fully acylated 4,6-O-benzylidene-1-thiomannopyranoside by radical-mediated redox rearrangement in high yields and regioselectivity. The D-rhamno-thioglycosides so obtained

• -rhamno-trisaccharide; deoxygenation on thioglycoside; multivalent glycosystems; one-pot sequential glycosylation; Pseudomonas aeruginosa; Introduction With the firm establishment of the critical roles played by oligosaccharides in diverse biological processes [1][2][3][4], the field of oligosaccharide

Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• purification, catalytically active P450 systems were reconstituted by addition of putidaredoxin (Pdx) and putidaredoxin reductase (PdR) from Pseudomonas putida as well as the pyridine cofactor NADH. Reactions were performed in 500 µL reaction volume. In order to avoid the stoichiometric addition of NADH

Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

• Jens Schmidt,
• Zeinab Khalil,
• Robert J. Capon and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2014, 10, 1228–1232, doi:10.3762/bjoc.10.121

• activity against the Gram-positive bacteria Staphylococcus aureus ATCC 25923 (IC50 1.8 μM), Staphylococcus epidermidis ATCC 12228 (IC50 0.9 μM) and Bacillus subtilis ATCC 6633 (IC50 1.8 μM), but was inactive (IC50 > 30 μM) against the Gram-negative bacteria Pseudomonas aeruginosa ATCC 10145 and Escherichia

Aminofluorination of 2-alkynylanilines: a Au-catalyzed entry to fluorinated indoles

• Antonio Arcadi,
• Emanuela Pietropaolo,
• Antonello Alvino and
• Véronique Michelet

Beilstein J. Org. Chem. 2014, 10, 449–458, doi:10.3762/bjoc.10.42

• biosynthesis mechanism as well as synthetic target for the development of novel medicinal agents [12]. Recently, 7-fluoroindole has been proposed as a potential candidate for the use in an antivirulence approach against persistent Pseudomonas aeruginosa infections [13]. Fluorine introduction in the benzene

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• rhamnolipids in Pseudomonas and sophorolipids in Candida apicola [36], but no examples for completely deuterated terpenes with a deuterium content of >98% as presented here are known. In conclusion, fermentation in fully deuterated medium as performed in this work may offer a good and practicable approach to

Biosynthesis of rare hexoses using microorganisms and related enzymes

• Zijie Li,
• Yahui Gao,
• Hideki Nakanishi,
• Xiaodong Gao and
• Li Cai

Beilstein J. Org. Chem. 2013, 9, 2434–2445, doi:10.3762/bjoc.9.281

• characterized the DTEase from Pseudomonas sp. ST-24 [28] and utilized this enzyme in the mass production of D-psicose with a final concentration of 150 g/L [29]. They further packed the immobilized DTEase from Pseudomonas sp. ST-24 (on Chitopearl beads) into a column that could be continuously used for 10 days

• galactitol catalyzed by Pseudomonas sp. ST 24 and the production yield was as high as 70%. The possible transformation route from galactitol to D-sorbose in this strain was deduced as follows (Scheme 4): the substrate galactitol is dehydrogenated at C-2 to afford D-tagatose followed by C-3 epimerization [43

• ]. Izumori et al. established a method for the preparation of D-sorbose directly from D-tagatose with immobilized DTEase from Pseudomonas sp. ST-24 and 2 g of D-sorbose could be obtained from 3 g of D-tagatose. The conversion yield maintained at about 70% each time even if the batch was repeated five times

Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids

• Yong-Chul Jeong and
• Mark G. Moloney

Beilstein J. Org. Chem. 2013, 9, 1899–1906, doi:10.3762/bjoc.9.224

• susceptible Enterococcus faecalis (VSE, E1), vancomycin resistant E. faecium (VanA VRE, E2)), and 2 strains of Streptococcus pneumoniae, including multi-drug resistant strain (MDRSP, P9), as well as 3 species of Gram-negative bacteria, consisting of Pseudomonas aeruginosa and 2 strains of Haemophilus

Chemoenzymatic synthesis and biological evaluation of enantiomerically enriched 1-(β-hydroxypropyl)imidazolium- and triazolium-based ionic liquids

• Paweł Borowiecki,
• Małgorzata Milner-Krawczyk and
• Jan Plenkiewicz

Beilstein J. Org. Chem. 2013, 9, 516–525, doi:10.3762/bjoc.9.56

• turn, conversion exceeding 57% was beneficial for high optical purity of the remaining alcohol (+)-5a (Table 1, entries 6 and 7, >97% ee). In the lipase-catalyzed acetylation of alcohol (±)-3b the best results were achieved with native Pseudomonas fluorescens lipase (Amano AK) suspended in 2-methyl-2

• separation of 1-(1H-imidazol-1-yl)propan-2-ol (±)-3a proceeded with excellent enantioselectivity, exceeding E = 500, in a short reaction time (5 h), by using a native enzymatic preparation from Pseudomonas fluorescens (Amano AK) as biocatalyst. In turn, after many trials we found that the kinetic separation

De novo synthesis of D- and L-fucosamine containing disaccharides

• Daniele Leonori and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 332–341, doi:10.3762/bjoc.9.38

• -Garner aldehydes. These differentially protected monosaccharide building blocks were utilized to prepare disaccharides present on the surface of Pseudomonas aeruginosa bacteria. Keywords: de novo synthesis; fucosamine; glycan; pseudomonas aeruginosa; vaccine; Introduction Protein functions are directly

• bacteria Pseudomonas aeruginosa. P. aeruginosa is a nosocomial pathogen that is involved in ventilator-associated pneumonia and has become resistant to many antimicrobials. The somatic pili of P. aeruginosa are a major virulence factor playing a pivotal role in the adherence and invasiveness of the

Efficient synthesis of phenylene-ethynylene rods and their use as rigid spacers in divalent inhibitors

• Francesca Pertici,
• Norbert Varga,
• Arnoud van Duijn,
• Matias Rey-Carrizo,
• Anna Bernardi and
• Roland J. Pieters

Beilstein J. Org. Chem. 2013, 9, 215–222, doi:10.3762/bjoc.9.25

• phenylene units. Preliminary applications of these rods in divalent systems are shown. Inhibition studies with Pseudomonas Aeruginosa lectin LecA showed that the rigid spacer proved greatly beneficial for the inhibitory potency. Keywords: multivalent carbohydrates; LecA inhibition; phenylene ethynylene

• of aromatic rings. One of the spacers was incorporated into the structure of a divalent galactoside ligand and was used to inhibit the virulence-linked lectin LecA of Pseudomonas aeruginosa [27][28]. Results and Discussion Synthetic strategies Depending on the number of units in the spacer, two

• obtained after deprotection of the alkyne moieties with K2CO3. Preliminary application As part of our program on bacterial adhesion inhibition by multivalent carbohydrates, the bacterial lectin LecA, a virulence factor of the problematic pathogen Pseudomonas aeruginosa is a target of interest [30][31

Multivalent display of the antimicrobial peptides BP100 and BP143

• Imma Güell,
• Rafael Ferre,
• Kasper K. Sørensen,
• Esther Badosa,
• Iteng Ng-Choi,
• Emilio Montesinos,
• Eduard Bardají,
• Lidia Feliu,
• Knud J. Jensen and
• Marta Planas

Beilstein J. Org. Chem. 2012, 8, 2106–2117, doi:10.3762/bjoc.8.237

• amylovora, Xanthomonas axonopodis pv. vesicatoria and Pseudomonas syringae pv. syringae [28][29]. BP100 displayed minimum inhibitory concentration (MIC) values in the range 2.5–7.5 μM and also showed low hemolysis (22% at 150 μM). BP143, which contains one D-amino acid, was as active, significantly less

• phytopathogenic bacteria Erwinia amylovora, Xanthomonas axonopodis pv. vesicatoria, and Pseudomonas syringae pv. syringae, and of human pathogenic bacteria Escherichia coli, Staphylococcus aureus, Lysteria monocytogenes, and Salmonella enterica at 0.6, 1.2, 2.5, 5, 7.5, 10 and 20 μM (Table 1). The antibacterial

• C311H526N72O62, 6262.022 Da). Bacterial strains and growth conditions As described in [28], the following plant pathogenic and foodborne bacterial strains were used: Erwinia amylovora PMV6076 (Institut National de la Recherche Agronomique, Angers, France), Pseudomonas syringae pv. syringae EPS94 (Institut de

Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

• H. Bauke Albada,
• Alina-Iulia Chiriac,
• Michaela Wenzel,
• Maya Penkova,
• Julia E. Bandow,
• Hans-Georg Sahl and
• Nils Metzler-Nolte

Beilstein J. Org. Chem. 2012, 8, 1753–1764, doi:10.3762/bjoc.8.200

• pathogens. Even if differences can be seen in the Gram-negative values, none of the RW-peptides was very active. Unfortunately, none of the peptides showed significant activity against Pseudomonas aeruginosa, a prominent pathogen that causes infections in e.g., cystic fibrosis patients. However, activities

• in Table 2) The minimal inhibitory concentrations (MIC) were tested against Escherichia coli DSM 30083, Acinetobacter baumannii DSM 30007, Pseudomonas aeruginosa DSM 50071, Bacillus subtilis DSM 402, Staphylococcus aureus DSM 20231 (type strain), and Staphylococcus aureus ATCC 43300 (MRSA) in a

Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity

• Marta De Zotti,
• Barbara Biondi,
• Cristina Peggion,
• Matteo De Poli,
• Haleh Fathi,
• Simona Oancea,
• Claudio Toniolo and
• Fernando Formaggio

Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129

• , Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Salmonella entereditis 13076, and Proteus mirabilis ATCC 10975. The well-known antibiotics bacitracin and tetracyclin (10 μg/disk) were used as controls. List of primary structures and abbreviations for the

Low-generation dendrimers with a calixarene core and based on a chiral C₂-symmetric pyrrolidine as iminosugar mimics

• Marco Marradi,
• Stefano Cicchi,
• Francesco Sansone,
• Alessandro Casnati and
• Andrea Goti

Beilstein J. Org. Chem. 2012, 8, 951–957, doi:10.3762/bjoc.8.107

• enhance the avidity of interactions between glycans and lectins [15]. Some glycocalixarenes have shown remarkable inhibition properties towards galectins [21][22] or Pseudomonas Aeruginosa lectin [23], the inhibition ability being dependent on the macrocyclic conformation and presentation of the glycoside

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

• distance (Figure 2) [140][141][142]. In another study, a combinatorial library of fucosyl-peptide dendrimers was synthesized and screened for binding to the fucose-specific lectin (LecB) from Pseudomonas aeruginosa, a pathogen causing severe infections in patients leading to chronic inflammation in the

Identification and isolation of insecticidal oxazoles from Pseudomonas spp.

• Florian Grundmann,
• Veronika Dill,
• Andrea Dowling,
• Aunchalee Thanwisai,
• Edna Bode,
• Narisara Chantratita,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 749–752, doi:10.3762/bjoc.8.85

• , Penryn, Cornwall, TR10 9EZ, UK Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand 10.3762/bjoc.8.85 Abstract Two new and five known oxazoles were identified from two different Pseudomonas strains in addition to the known pyrones pseudopyronine

• intermediates were also investigated revealing interesting biological activities for several compounds despite their overall simple structures. Keywords: insecticidal activity; labradorin; oxazole; Pseudomonas; secondary metabolite; Findings During our search for novel natural products from entomopathogenic

• its 16S-rRNA gene revealing it to be a Pseudomonas sp. with closest homology to P. putida (100% similarity: Supporting Information File 1, Figure S4) [11][12][13][14]. As judged on the basis of high-resolution MALDI–MS and LC–ESIMS/MS data the well-known entomopathogenic P. entomophila [15][16] also