Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• (Figure 1) are a family of linear peptide/polyketide natural products isolated from the bacteria Burkholderia sp. FERM BP-3421 [1][2][3] (originally identified as Pseudomonas sp. No 2663) and Burkholderia sp. MSMB 43 [4][5]. These compounds are of interest due to their ability to bind to a subunit of the

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• rutaceous plants [9]. Examples from microbes include chymase inhibitors SF2809-I to VI from an actinomycete of the genus Dactylosporangium [10], a quorum sensing signaling molecule 2,4-dihydroxyquinoline (DHQ, 4) from Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia thailandensis, [7], and 4-O

• emerging source of bioactive molecules. Many new structure classes, even after being spun off as a new genus from Pseudomonas in 1992 [14], have been discovered from this group, which, along with their large genomes comparable to those of actinomycetes or myxobacteria, demonstrate a higher capacity of

• . Though not alkylated, the close structural similarity to 3 suggests that 1 is also a member of the 2-alkyl-4-quinolone class signaling molecules/antibiotics known from Pseudomonas aeruginosa and some Burkholderia species [26][27]. Quinolones of this class are classified into two lineages, those with or

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• for their ability to interfere in the biofilm formation of Staphylococcus aureus DSM1104 and Pseudomonas aeruginosa PA14 [51]. The biofilm inhibition assay was performed in 96-well microtiter plates using the microtiter dish biofilm formation assay described by O’Toole [52], with minor modifications

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

• David C. B. Siebert,
• Roman Sommer,
• Domen Pogorevc,
• Michael Hoffmann,
• Silke C. Wenzel,
• Rolf Müller and
• Alexander Titz

Beilstein J. Org. Chem. 2019, 15, 2922–2929, doi:10.3762/bjoc.15.286

• Saarbrücken, Germany 10.3762/bjoc.15.286 Abstract The argyrins are secondary metabolites from myxobacteria with antibiotic activity against Pseudomonas aeruginosa. Studying their structure–activity relationship is hampered by the complexity of the chemical total synthesis. Mutasynthesis is a promising

• variants of known antibiotics are being developed and were approved in the last few years, also comprising drugs active against Pseudomonas aeruginosa, one of the currently most problematic bacterial pathogens [1]. Especially among the quinolones, cephalosporins and carbapenems new compounds have been

Skeletocutins M–Q: biologically active compounds from the fruiting bodies of the basidiomycete Skeletocutis sp. collected in Africa

• Tian Cheng,
• Clara Chepkirui,
• Cony Decock,
• Josphat C. Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2782–2789, doi:10.3762/bjoc.15.270

• coli (E. coli) DSM498, Chromobacterium violaceum (C. violaceum) DSM30191, and Pseudomonas aeruginosa (P. aeruginosa) PA14. Moreover, the filamentous fungus Mucor plumbeus (M. plumbeus) MUCL49355 and the yeasts Candida tenuis (C. tenuis) MUCL29892, Pichia anomala (P. anomala) DSM6766, and Candida

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• marinum; diterpene synthase (BAP82229), Streptomyces sp. ND90; tsukubadiene synthase (EIF90392), Streptomyces tsukubaensis NRRL 18488; terpene synthase (ZP_00085244), Pseudomonas fluorescens PfO-1; spiroalbatene synthase (WP_030426588.1), Allokutzneria albata; spatadien synthase (WP_095757924.1

Doebner-type pyrazolopyridine carboxylic acids in an Ugi four-component reaction

• Maryna V. Murlykina,
• Oleksandr V. Kolomiets,
• Maryna M. Kornet,
• Yana I. Sakhno,
• Sergey M. Desenko,
• Victoriya V. Dyakonenko,
• Svetlana V. Shishkina,
• Oleksandr A. Brazhko,
• Vladimir I. Musatov,
• Alexander V. Tsygankov,
• Erik V. Van der Eycken and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2019, 15, 1281–1288, doi:10.3762/bjoc.15.126

• (strain 1211), Staphylococcus aureus (strain 2231) (gram-positive) and Escherichia coli (strain 1257), Pseudomonas aeruginosa (strain 1111) (gram-negative). Generally, the compounds were found to be less active than nitroxoline being the reference substance. The results obtained indicate that some

A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12

• Seema V. Kanojia,
• Sucheta Chatterjee,
• Subrata Chattopadhyay and
• Dibakar Goswami

Beilstein J. Org. Chem. 2019, 15, 490–496, doi:10.3762/bjoc.15.42

• vinyl acetate in diisopropyl ether (DIP) was attempted. However, the yield and enantioselectivity of the desired alcohol (S)-4 were very poor (Table 1, entry 1). Also the acetylation of (±)-4 with vinyl acetate in diisopropyl ether using Candida rugosa lipase (CRL) and Pseudomonas fluorescens lipase

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• Administration, Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8519, Japan 10.3762/bjoc.15.27 Abstract Pseudomonas cichorii, which causes varnish spots on lettuce and seriously damages lettuce production during the

• alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce. Keywords: cichorinotoxin; lipodepsipeptide; necrotic lesion of lettuce; phytotoxin; Pseudomonas cichorii; Introduction

• Pseudomonas cichorii causes varnish spots on lettuce. Varnish spots, also called midrib rot or bacterial rot [1][2][3][4], are dark brown and can induce necrotic lesions [1][2][3][4][5][6][7]. P. cichorii, isolated by us, infects a wide range of host plants, including monocot and dicot species (e.g

Synthesis and biological activity of methylated derivatives of the Pseudomonas metabolites HHQ, HQNO and PQS

• Sven Thierbach,
• Max Wienhold,
• Susanne Fetzner and
• Ulrich Hennecke

Beilstein J. Org. Chem. 2019, 15, 187–193, doi:10.3762/bjoc.15.18

• are associated with quorum sensing and virulence of the human pathogen Pseudomonas aeruginosa, have been prepared. While the synthesis by direct methylation was successful for 3-unsubstituted 2-heptyl-4(1H)-quinolones, methylated derivatives of the Pseudomonas quinolone signal (PQS) were synthesized

• in the lung of cystic fibrosis patients, was inhibited in planktonic growth and cellular respiration by the 4-O-methylated derivatives of HQNO and HHQ, respectively. Keywords: antibiotic acitivity; methylation; Pseudomonas aeruginosa; quinolones; quorum sensing; Introduction 2-Alkyl-4(1H

• )-quinolones (AQs) have been identified as natural products produced by higher plants of the Rutaceae family as well as by some microorganisms including Alteromonas, Burkholderia and Pseudomonas species [1][2][3][4][5][6][7][8][9]. Plant-derived AQs occur with alkyl chains of different lengths, branches and

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• bacterium Pseudomonas haloplanktis [78]. These genes encode for proteins involved in assembly of type IV pili (T4P) [91]. Since bacterial lectins are often located at the terminal ends of pili or fimbriae, this homology is of potential interest as it indicates that Mtb might express carbohydrate-binding

Repurposing the anticancer drug cisplatin with the aim of developing novel Pseudomonas aeruginosa infection control agents

• Mingjun Yuan,
• Song Lin Chua,
• Yang Liu,
• Daniela I. Drautz-Moses,
• Joey Kuok Hoong Yam,
• Thet Tun Aung,
• Roger W. Beuerman,
• May Margarette Santillan Salido,
• Stephan C. Schuster,
• Choon-Hong Tan,
• Michael Givskov,
• Liang Yang and
• Thomas E. Nielsen

Beilstein J. Org. Chem. 2018, 14, 3059–3069, doi:10.3762/bjoc.14.284

• compounds in both academia and the pharmaceutical industry. Here, we report how the widely used antitumor drug cisplatin may be repurposed as an effective antimicrobial against the nosocomial pathogen Pseudomonas aeruginosa. Cisplatin was found to effectively kill strains of P. aeruginosa. In such

• infections. Keywords: biofilm; cisplatin; Pseudomonas aeruginosa; resistance; type III secretion; Introduction Pseudomonas aeruginosa is a leading nosocomial pathogen which causes, among others, corneal, chronic otitis media, urinary tract (UTI) and respiratory tract infections [1]. P. aeruginosa is also

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• resistance: 1. Priority 1 – Critical: Acinetobacter baumannii, carbapenem-resistant Pseudomonas aeruginosa, carbapenem-resistant Enterobacteriaceae, carbapenem-resistant, 3rd generation cephalosporin-resistant 2. Priority 2 – High: Enterococcus faecium, vancomycin-resistant Staphylococcus aureus, methicillin

• ], Helicobacter pylori [41], Pseudomonas aeruginosa [42], Campylobacter jejuni [43], Treponema pallidum [44], the cyanobacterium Synechocystis spp. [45], Mesorhizobium loti [46] and Mycoplasma pneumoniae [47]. Furthermore, partial PINs for Bacillus subtilis [48] and Streptococcus pneumoniae [49] have been

• /NusE binding with an IC50 of 34.7 μM. Its antimicrobial properties were also evaluated against a panel of clinically relevant microorganisms such as Enterococcus faecalis, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, Escherichia coli, Proteus vulgaris and

Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products

• Stephen M. Geddis,
• Teodora Coroama,
• Suzanne Forrest,
• James T. Hodgkinson,
• Martin Welch and
• David R. Spring

Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245

• analogues was observed to inhibit production of the virulence factor pyocyanin in the human pathogen Pseudomonas aeruginosa, which may be a result of their similarity to the Pseudomonas quinolone signal (PQS) quorum sensing autoinducer. This provided new insights regarding the effect of N-substitution in

• -position, there is a structural resemblance to the Pseudomonas quinolone signal (PQS), and its biosynthetic precursor 2-heptyl-4(1H)-quinolone (HHQ), which are vital to the cooperative behaviour of the human pathogen Pseudomonas aeruginosa via quorum sensing (QS). This is a means by which bacteria alter

• , providing valuable new SAR insights regarding N-substitution of PQS and HHQ analogues. A family of quinolone natural products 1–8, which were first isolated from Pseudonocardia sp. CL38489 by Dekker et al. [3], shown alongside the structure of the Pseudomonas quinolone signal (PQS), a key autoinducer used

Non-native autoinducer analogs capable of modulating the SdiA quorum sensing receptor in Salmonella enterica serovar Typhimurium

• Matthew J. Styles and
• Helen E. Blackwell

Beilstein J. Org. Chem. 2018, 14, 2651–2664, doi:10.3762/bjoc.14.243

• tumefaciens [45][51][52][53][54]; AbaR from Acinetobacter baumannii [47][55]; LasR [45][51][52][53][54][56], QscR [57], and RhlR [48][56] from Pseudomonas aeruginosa; ExpR1 and ExpR2 from Pectobacterium carotovora [46][58]; and LuxR from Vibrio fischeri [45][51][52][53][54]. The full set of 151 compounds

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• , 66123 Saarbrücken, Germany German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Saarbrücken, Germany 10.3762/bjoc.14.241 Abstract The Gram-negative opportunistic pathogen Pseudomonas aeruginosa causes severe nosocomial infections. It uses quorum sensing (QS) to regulate and

• coordinate population-wide group behaviours in the infection process like concerted secretion of virulence factors. One very important signalling network is the Pseudomonas quinolone signal (PQS) QS. With the aim to devise novel and innovative anti-infectives, inhibitors have been designed to address the

• highlights the published drug discovery efforts providing insights into the compound binding modes if available. Furthermore, suitability of the individual targets for pathoblocker design is discussed. Keywords: anti-infectives; pathoblockers; PQS; Pseudomonas aeruginosa; quorum sensing; Introduction In

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• pathogens, [4] Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter species, were initially identified as the most problematic ones. In 2017, an extended list of twelve pathogens, currently considered as those with the highest

• , multiple QS mechanisms exist within one species. For example in P. aeruginosa, four signaling systems have been identified to date, which are highly interconnected and mutually influence each other [30]. Some bacteria employ rather specific quorum sensing molecules, such as the Pseudomonas Quinolone Signal

• FmlH (compounds 8 and 9) and Pseudomonas aeruginosa LecA (compounds 10–12). Mannosides and fucosides as inhibitors of P. aeruginosa LecB. β-Cyclodextrin-based antitoxin 19 against S. aureus α-hemolysin and the decavalent Shiga toxin inhibitors STARFISH (20) and DAISY (21). The mechanism of quorum

Impact of Pseudomonas aeruginosa quorum sensing signaling molecules on adhesion and inflammatory markers in endothelial cells

• Carmen Curutiu,
• Florin Iordache,
• Veronica Lazar,
• Aurelia Magdalena Pisoschi,
• Aneta Pop,
• Mariana Carmen Chifiriuc and
• Alina Maria Hoban

Beilstein J. Org. Chem. 2018, 14, 2580–2588, doi:10.3762/bjoc.14.235

• of Agronomical Sciences and Veterinary Medicine, Faculty of Veterinary Medicine, Bucharest, Romania Institute of Cellular Biology and Pathology Nicolae Simionescu of Romanian Academy, Romania 10.3762/bjoc.14.235 Abstract Pseudomonas aeruginosa relies on the quorum sensing (QS) signaling system as a

• develop anti-QS therapeutic strategies to fight against P. aeruginosa infections. Keywords: adhesion; host–pathogen interaction; inflammation; Pseudomonas; quorum sensing; Introduction Pseudomonas (P.) aeruginosa is an opportunistic pathogen that causes severe and persistent infections in immune

• . Pseudomonas aeruginosa is recognized as the principal pathogen responsible of high morbidity and mortality in patients with cystic fibrosis, one of the most common life-threatening autosomal recessive genetic disease in Northwest European populations, determined by mutations in the cystic fibrosis

The enzymes of microbial nicotine metabolism

• Paul F. Fitzpatrick

Beilstein J. Org. Chem. 2018, 14, 2295–2307, doi:10.3762/bjoc.14.204

• NicA2 instead catalyzes oxidation of the substrate carbon–nitrogen bond as shown in Scheme 4. Cloning and expression of the protein encoded by the nox gene of Pseudomonas sp. HZN6 showed that it also catalyzes oxidation of nicotine to pseudooxynicotine [54]. The sequence of the protein is most similar

• enzyme as shown in Scheme 9, with the hydrolytic step being nonenzymatic. This is essentially the same reaction as that catalyzed by A. nicotinovorans γ-N-methylaminobutyrate demethylating oxidase (Mabo). E. coli expressing the sap gene from Pseudomonas sp. HZN6 will catalyze the NADP+-dependent

• converting 3-succinoylpyrimidine to 6-hydroxy-3-succinoylpyridine [48]. These results support the identification of SpmABC as a molybdopterin enzyme that catalyzes this step in the pathway. Enzymes with this activity do not appear to have been identified as yet for P. putida S5 and Pseudomonas sp. HZN6. HspA

Defining the hydrophobic interactions that drive competence stimulating peptide (CSP)-ComD binding in Streptococcus pneumoniae

• Bimal Koirala,
• Robert A. Hillman,
• Erin K. Tiwold,
• Michael A. Bertucci and
• Yftah Tal-Gan

Beilstein J. Org. Chem. 2018, 14, 1769–1777, doi:10.3762/bjoc.14.151

• modulators against a multitude of Gram-negative bacterial species, including Pseudomonas aeruginosa, Vibrio fischeri, Vibrio harveyi, Vibrio cholerae, and Acinetobacter baumannii has been conducted [6][7][8][9][10]. Contrary, with the exception of the accessory gene regulator (agr) QS circuitry in

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• Burkholderia produce many more secondary metabolites than reported, as this group was previously classified into the genus Pseudomonas [8]. In fact, the high capacity of Burkholderia in secondary metabolism is demonstrated by the presence of unique functionalities, such as monocyclic 3-pyrazolone [9], α

• Pseudomonas aeruginosa. A series of chemoecological studies of P. aeruginosa has uncovered multifunctional roles of this quinolone class as antibacterial, antifungal, iron-chelating, and autoinducer agents to assist the survival of the producing organisms [32]. Additionally, drug discovery attempts have

• collected on a Bruker micrOTOF focus mass spectrometer. Collection of Burkholderia strains and broth screening Burkholderia strains were collected by serial dilution plating on Pseudomonas agar supplemented with C-F-C (Oxoid, Basingstoke, England) from rhizosphere soils of Welsh onion and cucumber (Cucumis

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• could facilitate DNA cleavage. Moreover, these complexes showed improved biocidal activity than the free ligands against various bacterial strains such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Klebsiella pneumonia. Nair et al. synthesized and

Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• ylides, and (diacyloxyiodo)arenes were also examined for their antibacterial activities against ice nucleation active Pseudomonas syringae, and aryliodonium salts, especially those with electron-withdrawing groups, exhibit higher antibacterial activities [49]. Despite the long history of diaryliodonium

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• resistance genes) and the emergence of multidrug resistant strains [59]. In addition, extracellular DNA has been shown to be important for biofilm establishment and maintenance by pathogenic bacteria, such as Pseudomonas aeruginosa and Staphylococcus aureus [60][61][62]. Some other bacteria, such as E. coli

What contributes to an effective mannose recognition domain?

• Christoph P. Sager,
• Deniz Eriş,
• Martin Smieško,
• Rachel Hevey and
• Beat Ernst

Beilstein J. Org. Chem. 2017, 13, 2584–2595, doi:10.3762/bjoc.13.255

• glycosides on mammalian cell surfaces. After this initial contact, they can infect host cells and form biofilms, both of which are key factors for their survival [9][27][28]. Examples of such opportunistic bacterial species binding to mannosides on host cells include Pseudomonas aeruginosa with its membrane

• additional hydroxy group would not contribute the maximum penalty associated with an isolated one. The cost of desolvating calcium ions (Figure 5). Opportunistic bacteria such as Pseudomonas aeruginosa or Burkholderia cenocepacia have incorporated a second calcium ion into their binding site, coordinating