N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• Roseobacter group (Rhodobacteraceae) are important members of many marine ecosystems. Similar to other Gram-negative bacteria many roseobacters produce N-acylhomoserine lactones (AHLs) for communication by quorum sensing systems. AHLs regulate different traits like cell differentiation or antibiotic

• knowledge on their biosynthesis, the underlying gene organization, as well as their function in many bacteria [11][12][13]. In the Roseobacter group, AHLs are involved, e.g., in antibiotic production [9] or cell differentiation [10]. Although many other bacterial signalling compounds must exist, only few of

Stereodivergent approach in the protected glycal synthesis of L-vancosamine, L-saccharosamine, L-daunosamine and L-ristosamine involving a ring-closing metathesis step

• Pierre-Antoine Nocquet,
• Aurélie Macé,
• Frédéric Legros,
• Jacques Lebreton,
• Gilles Dujardin,
• Sylvain Collet,
• Arnaud Martel,
• Bertrand Carboni and
• François Carreaux

Beilstein J. Org. Chem. 2018, 14, 2949–2955, doi:10.3762/bjoc.14.274

• vinyl ethers as key step of reaction sequences developed. Keywords: 3-amino glycals; diastereoselective additions to aldehydes; pluramycins; ring-closing metathesis; vinyl ethers; Introduction Several classes of medicinally useful molecules with antibiotic and anticancer activity contain in their

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

• Laura Carro School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK 10.3762/bjoc.14.267 Abstract Antibiotics are potent pharmacological weapons against bacterial infections; however, the growing antibiotic resistance of microorganisms is compromising the efficacy

• of the currently available pharmacotherapies. Even though antimicrobial resistance is not a new problem, antibiotic development has failed to match the growth of resistant pathogens and hence, it is highly critical to discover new anti-infective drugs with novel mechanisms of action which will help

• medicine. Unfortunately, since their use is intrinsically linked to the appearance of resistance, threatening antibiotic-resistant bacteria levels are being observed, compromising the efficacy of nearly all available antibiotics to cure infectious diseases [2][3][4]. The rise in the percentage of

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

• bacteriostatic chemotherapies to treat infection imposes evolutionary pressures that drive rapid resistance development and spread within and among bacterial populations [2][3]. Antibiotic resistant clinical isolates have been observed for almost every known antibiotic, and the pace of new antibiotic discovery

The design and synthesis of an antibacterial phenothiazine–siderophore conjugate

• Abed Tarapdar,
• James K. S. Norris,
• Oliver Sampson,
• Galina Mukamolova and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2018, 14, 2646–2650, doi:10.3762/bjoc.14.242

• , Department of Infection, Immunity and Inflammation, University of Leicester, Maurice Shock Medical Sciences Building, University Road, Leicester, LE1 9HN, UK 10.3762/bjoc.14.242 Abstract Siderophore–antibiotic conjugates consist of an antibiotic covalently linked by a tether to a siderophore. Such

• antibacterial agents. Keywords: NDH-2; phenothiazine; siderophore; siderophore–antibiotic; siderophore conjugate; Introduction One of the biggest challenges facing the modern society is antibiotic resistance and the prospect of current antibiotics becoming near redundant against previously treatable

• infections [1]. To meet this challenge there is a desperate need for new antibiotics, antibiotic targets and strategies to enhance the efficacy of current antibiotics [2]. One novel strategy which is receiving significant interest is the manipulation of bacterial iron transport pathways to deliver

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

• infections [2]. Especially in the case of Gram-negative bacteria, an urgent need for novel medicines has been identified while the pipeline of drug candidates is literally running dry and a desirable renaissance of the golden age of antibiotic drug research in ‘big pharma’ is currently not to be seen on the

• horizon [3][4]. Nevertheless, some innovative strategies to be explored for their clinical applicability in combating bacterial infections have been devised in the last decades mostly driven by academic research [5][6][7]. In contrast to addressing classical antibiotic drug targets involved in vital

• resist antibiotic treatment via several mechanisms. First and foremost, it possesses an intrinsic resistance to many antibiotics because of the low permeability of its cell wall and due to the action of a number of efflux pumps as well as β-lactamases. Efflux pumps in particular are nifty molecular

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

• pressure can lead to the overgrowth of the initial infective population with a resistant variant of the pathogen, rendering the antibiotic substance ineffective. Especially prevalent in the hospital setting, the abundance of resistance prevents efficient treatment of infected patients. The so-called ESKAPE

• , or the formation of bacterial biofilms, can be inhibited. Numerous reviews have detailed these processes addressing various QS pathways [30][72][73]. The antibiotic azithromycin (22), which does not have significant bactericidal activity for P. aeruginosa, but interferes with its quorum sensing

• pathways, was studied in a clinical trial (Figure 6) [74]. The macrolide antibiotic of natural origin, which does not resemble the structures of signal molecules, was shown to reduce the presence of quorum sensing molecules in vitro and in vivo. It prevented the selection of QS-mutants (lasR) that rapidly

Design and synthesis of C₃-symmetric molecules bearing propellane moieties via cyclotrimerization and a ring-closing metathesis sequence

• Sambasivarao Kotha,
• Saidulu Todeti and
• Vikas R. Aswar

Beilstein J. Org. Chem. 2018, 14, 2537–2544, doi:10.3762/bjoc.14.230

• units in bioactive natural products and pharmaceuticals. Some of these propellanes exhibit intresting properties like antibiotic, antifungal, anticancer, platelet-activating factor antagonistic and antibacterial activities. The propellane skeleton is present in many alkaloids such as aknadinine (1

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

• Luce Mattio,
• Loana Musso,
• Leonardo Scaglioni,
• Andrea Pinto,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

• , is an imperative goal to stay ahead of the evolution of antibiotic resistance. Herein we report the synthesis of a 3-decyltetramic acid analogue of the ureido dipeptide natural antibiotic leopolic acid A. The key step in the synthetic strategy is an intramolecular Lacey–Dieckmann cyclization reaction

• 20th century. However, the continued emergence of multidrug-resistant bacteria, mainly due to the abuse of antimicrobial molecules (e.g., for treatment of bacterial skin diseases [1]), emphasises the urgent need for novel antibiotic families. In this regard, natural products are privileged compounds

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

• Kai Zhang,
• Jiarong Li,
• Honglin Liu,
• Haiyou Wang and
• Lamusi A

Beilstein J. Org. Chem. 2018, 14, 2321–2330, doi:10.3762/bjoc.14.207

• , these analogues may also have antibiotic, antifungal, anticancer, antiparasitic, and immunosuppressive properties. Conclusion This study demonstrated a viable approach to synthesize spinetoram J and its analogues. Compared with the previous semi-synthesis of spinetoram J, the improved semi-synthesis

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• an antibiotic [94]. In this methodology, N-(p-hydroxyphenyl)cyanoacetamides 65 were cyclized to corresponding 4-spiro-β-lactam-3-carbonitriles 66 in useful yields using PIDA (15) as an electrophile in the presence of KOH as base in anhydrous ethanol at room temperature (Scheme 22). In 2014, Fan and

• starting from catechol derivative 142. Marine sesquiterpenoids are mainly known for their biological importance such as antitumor, antiviral and antibiotic properties [132]. In this report, the catechol-derived starting substrate 142 was cyclized to spirocyclic product 143 in 67% yield using PIFA (31) as

• pathway for the synthesis of the naturally occurring antibiotic platensimycin (154) which is isolated from Streptomyces platensis. In this report, 6-methoxy-1,4-naphthoquinone-4-ethylene ketal (153) was synthesized by intermolecular oxidative cyclization of 7-methoxy-α-naphthol (152) with ethylene glycol

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

• (CSP), to acquire antibiotic resistance and establish an infection. In this work, we sought to define the binding pockets within the ComD1 receptor used for binding the hydrophobic side-chain residues in CSP1 through the introduction of highly-conservative point mutations within the peptide

• as the competence regulon, is centered on the competence stimulating peptide (CSP, Figure 1). S. pneumoniae utilizes the regulon to become competent and acquire antibiotic resistance from the environment, initiate its attack on the human host through virulence factor production, and protect itself

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• skunk oil [4], alliin (2), the precursor to 1-propenesulfinic acid which rearranges to the sulfine (Z)-propanethial-S-oxide, the lachrymatory factor of onions, (Allium cepa L), and allicin (3), the thiosulfinate with antibiotic properties from garlic (Allium sativum L.) [5]. On the other molecular

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

•  15) [63]. Similar reaction conditions were applied by Nie et al. in the total synthesis of the nucleoside antibiotic A201A [64]. Notably, the n-Bu3P-ADDP reagent system led here to the formation of the pure α-glycoside. Likewise, a Mitsunobu glycosylation of complex phenols was successfully

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

• Jiyun Sun,
• Xiaohua Zhen,
• Huaibin Ge,
• Guangtao Zhang,
• Xuechan An and
• Yunfei Du

Beilstein J. Org. Chem. 2018, 14, 1452–1458, doi:10.3762/bjoc.14.123

• potential anti-HIV drug bearing a NCF3 moiety. 2H-Azirines are a class of highly strained and reactive molecules containing a C–N double bond. The exclusive framework can be found in some natural products [43][44][45][46][47], which were shown to possess antibiotic activities [43][44]. Furthermore

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

• antibiotic producers (as of Jan. 20, 2018). As part of our program to further explore this unique pharmacological resource, rhizobacteria of the genus Burkholderia were collected and tested for the production of antimicrobial metabolites against a panel of plant and animal pathogens consisting of 4 bacteria

Acyl-group specificity of AHL synthases involved in quorum-sensing in Roseobacter group bacteria

• Lisa Ziesche,
• Jan Rinkel,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 1309–1316, doi:10.3762/bjoc.14.112

• regulate several physiological traits regulated by cell density, the ‘quorum’ [11][12][13][14][15][16], in roseobacters, e.g., in the production of the antibiotic tropodithietic acid in Phaeobacter inhibens [15] and cell differentiation in Dinoroseobacter shibae [14]. Roseobacter group AHLs are

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• and in a number of other natural compounds that have shown a highly diverse range of biological activity [1][2][3][4][5][6][7][8][9], like the inhibitory activity of inositol monophosphatase [10][11], antitumor [12], antibiotic [12][13], and antibacterial activity [14] and lipoxygenase inhibitor

• activity [14][15][16]. Troponoids 3–10 have been reported in the literature in a number of natural forms (Figure 1) [1][2][3][4][5][6][7][8]. These compounds have a structural class spacing from the simple monocyclic tropones, such as the potent antifungal and antibiotic monoterpene β-thujaplicin (4) [17

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

• the past few years. Keywords: alkylators; antibiotic; anticancer; antineoplastic; antiproliferative; DNA recognition; groove binders; hairpin polyamides; Hoechst 33258; intercalators; Review 1. Introduction DNA is one of the central components of cellular machinery and storage unit of genetic

Fluorocyclisation via I(I)/I(III) catalysis: a concise route to fluorinated oxazolines

• Felix Scheidt,
• Christian Thiehoff,
• Gülay Yilmaz,
• Stephanie Meyer,
• Constantin G. Daniliuc,
• Gerald Kehr and
• Ryan Gilmour

Beilstein J. Org. Chem. 2018, 14, 1021–1027, doi:10.3762/bjoc.14.88

• siderophore antibiotic D-fluviabactin, the cytotoxic agent westiellamide, the antifungal macrodiolide leupyrrin A1 and the antitumour compound BE-70016 (Figure 1). In addition, synthetic polymers based on the 2-oxazoline building block constitute versatile platforms for a range of biomedical applications

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• resultant compounds are called carbocyclic C-nucleosides. Examples of natural and synthetic C-nucleosides. Pseudouridine and formcycin are among several naturally occurring C-nucleosides that are being studied for their role in RNA biology and antibiotic properties respectively. In the recent past

Continuous multistep synthesis of 2-(azidomethyl)oxazoles

• Thaís A. Rossa,
• Nícolas S. Suveges,
• Marcus M. Sá,
• David Cantillo and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2018, 14, 506–514, doi:10.3762/bjoc.14.36

• antibiotic or antimicrobial properties such as pimprinine [4] or phenoxan [5] (Figure 1a). Also many synthetic active pharmaceutical ingredients (API) contain the oxazole as an active moiety [1][2][3]. Oxaprozin, for example, is an important non-narcotic, non-steroidal anti-inflammatory drug [6][7

• ]. Sulfamoxole is a broad-spectrum antibiotic for the treatment of bacterial infections (Figure 1b) [8]. In addition, ongoing studies show the potential of amino and amido-oxazoles to act as fluorescent dipeptidomimetics (Figure 1c) [9]. Due to their diene character, oxazoles find also use as intermediates in

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

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

• control experiments [58]. It is worth mentioning here that bacteria have different ways to interact with extracellular DNA. In some cases they can naturally internalize and integrate exogenous DNA (natural competence) and this can result in the acquisition of new genetic traits (e.g., antibiotic

• maintenance by pathogenic bacteria, such as P. aeruginosa and S. aureus [60][61][62]. In addition, eDNA with its negative charge can sequester cationic antibiotics contributing to antibiotic resistance; thus, removing eDNA from the biofilm matrix can weaken the biofilm and can raise its susceptibility to

• antibiotics. The fact that these cyclodextrin derivatives might be loaded with an antibiotic allows speculating that a possible antibiotic–CD complex could target the pathogen and in the meanwhile to bind and sequester extracellular DNA, inhibiting its role in vivo. Finally, a particular mention is deserved