Synthesis of Streptococcus pneumoniae serotype 9V oligosaccharide antigens

• Sharavathi G. Parameswarappa,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2020, 16, 1693–1699, doi:10.3762/bjoc.16.140

• Chemistry and Biochemistry, Arnimallee 22, 14195 Berlin, Germany 10.3762/bjoc.16.140 Abstract Streptococcus pneumoniae (SP) bacteria cause serious invasive diseases. SP bacteria are covered by a capsular polysaccharide (CPS) that is a virulence factor and the basis for SP polysaccharide and glycoconjugate

• are still of growing concern due to an increase in non-vaccine serotypes and the cost of implementing these expensive vaccines in national immunization programs [4][5][6]. CPS is an important bacterial virulence factor and is critical for the interaction with the host as it helps the bacteria to

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• bacteria Arthrobacter crystallopoietes (DSM 20117) and Bacillus megaterium (DSM 32). Keywords: antibacterial; Dictyoceratida; Nudibranchia; scalarane; sesterterpene; Introduction In habitats with intense competition and feeding pressure, such as coral reefs, sessile or slow-moving organisms commonly

• sesterterpene reported with a cyclopropane ring bridging the carbons C-3, C-22 and C-4 in ring A, and an acetoxy group at C-11 instead of C-12 in ring C (Figure 2). All ethyl acetate extracts, as well as the isolated new scalarane, showed antibacterial activity against the Gram-positive bacteria Arthrobacter

• were shown to share and cover various core functions of sponge metabolism by functionally equivalent symbionts, analogous enzymes, or biosynthetic pathways [16][79][80]. Another Spongia species, S. officinalis, was shown to harbour bacteria with terpenoid cyclases/protein prenyltransferases responsible

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

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

• -β-ᴅ-glucopyranosyl-2,3,4-trihydroxyquinoline (5) from an ascomycete of the genus Alternaria [8]. The genus Burkholderia sensu lato, within the class Betaproteobacteria, represents a polyphyletic group of bacteria, which undergoes reclassification into several lineages [11]. Members of this group are

• aureus FDA209P JC-1 (Gram-positive bacterium), Rhizobium radiobacter NBRC14554, Ralstonia solanacearum SUPP1541, Tenacibaculum maritimum NBRC16015 (Gram-negative bacteria), Candida albicans NBRC0197, and Saccharomyces cerevisiae S100 (yeasts). Oxidative burst, which is a transient production of massive

Synthesis of pyrrolidinedione-fused hexahydropyrrolo[2,1-a]isoquinolines via three-component [3 + 2] cycloaddition followed by one-pot N-allylation and intramolecular Heck reactions

• Xiaoming Ma,
• Suzhi Meng,
• Xiaofeng Zhang,
• Qiang Zhang,
• Shenghu Yan,
• Yue Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2020, 16, 1225–1233, doi:10.3762/bjoc.16.106

• have immuno modulatory activity [7][8]. Trolline has inhibitory activity against Gram-negative and Gram-positive bacteria [9], also as free radical scavenger in rat brain [10]. Organic chemists have been continuously interested in the development of methods for the synthesis of pyrrolo[2,1-a

Fabclavine diversity in Xenorhabdus bacteria

• Sebastian L. Wenski,
• Harun Cimen,
• Natalie Berghaus,
• Sebastian W. Fuchs,
• Selcuk Hazir and
• Helge B. Bode

Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84

• of the insect by the nematode, the bacteria are released from the nematode gut into the insect hemocoel where they start producing a diversity of different natural products to suppress the immune response and to kill the insects, to defend the carcass against food competitors, and to trigger the

• . budapestensis and X. szentirmaii, and a 50 kb biosynthesis gene cluster (BGC) was identified to be responsible for their formation (Figure 1) [20]. These compounds were of special interest because of their broad-spectrum bioactivity against Gram-positive and -negative bacteria, fungi, and protozoa [20][21

• , homologous BGCs can be found in Serratia plymuthica as well as in Dickeya zeae [20][25]. Like Xenorhabdus and Photorhabdus, these bacteria also belong to the order Enterobacterales and are producers of zeamines, which are structurally closely related to fabclavines and differ only in a postbiosynthetic

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• alternative therapeutics for the fight against multiresistant bacteria both for medicinal [22][23][24][25] and environmental purposes [26][27]. Several organic compounds were found to be “DNA photocleavers”, exhibiting their action at 312 nm, like [1,2,4]triazolo[4,3-a]quinoxaline [28] and quinoxalin-4(5H

Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku,
• Nobuyasu Matsuura,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 297–304, doi:10.3762/bjoc.16.29

• ongoing screening program to discover new natural products from coral-associated bacteria, we have recently reported a catecholate siderophore, labrenzbactin, from an alphaproteobacterium Labrenzia [17] and an unsaturated fatty acid with unique methylation pattern from a gammaproteobacterium Microbulbifer

• bacteria, Micrococcus luteus ATCC9341, Staphylococcus aureus FDA209P JC-1, Rhizobium radiobacter NBRC14554, Escherichia coli NIHJ JC-2, Tenacibaculum maritimum NBRC16015, and two yeasts, Candida albicans NBRC0197 and Saccharomyces cerevisiae S100, as indication strains. Mueller–Hinton Broth (Difco

• ), Sabouraud Dextrose Broth (Difco), and Marine Broth (Difco) were used for bacteria, yeasts, and Tenacibaculum maritimum NBRC16015, respectively. Compounds 1 and 2, the reference drugs kanamycin sulfate for bacteria, sulfamethoxazole for R. radiobacter NBRC14554 and T. maritimum NBRC16015, and amphotericin B

Absolute configurations of talaromycones A and B, α-diversonolic ester, and aspergillusone B from endophytic Talaromyces sp. ECN211

• Ken-ichi Nakashima,
• Junko Tomida,
• Takao Hirai,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 290–296, doi:10.3762/bjoc.16.28

• first time in over 50 years. Keywords: absolute configuration; endophytic fungus; glauconic acid; Talaromyces; tetrahydroxanthone; xanthenedione; Introduction The xanthones, which are a class of phenolic compounds produced by many different organisms, including plants, lichens, fungi, and bacteria

Convenient synthesis of the pentasaccharide repeating unit corresponding to the cell wall O-antigen of Escherichia albertii O4

• Tapasi Manna,
• Arin Gucchait and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2020, 16, 106–110, doi:10.3762/bjoc.16.12

• of devastating diarrheal infections in different countries [9]. The role of cell wall O-polysaccharides in regulating the virulence properties of bacteria is well established [10]. Recently, Naumenko et al. [11] reported the structure of the repeating unit of the cell wall O-polysaccharide of the E

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

• Gram-positive bacteria, Gram-negative bacteria, HeLa cells, and human erythrocytes) and were able to rationalize the specific impact of our modifications onto cell selectivity indices. Though all compounds demonstrated distinctly different cell toxicities in the ring-open and the ring-closed photoforms

• infectious diseases caused by Gram-positive or -negative bacteria, or for anticancer applications. We hypothesized that the lack of correlation between cell types might not only reflect different mechanisms of killing (possibly even within any pair of isomers), but that it may also be due to unique

Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose

• Lukáš Kerner and
• Paul Kosma

Beilstein J. Org. Chem. 2020, 16, 9–14, doi:10.3762/bjoc.16.2

• identified as a major mechanism contributing to antimicrobial resistance of Gram-negative pathogenic bacteria. Inhibition of the corresponding enzymatic steps, specifically the transfer of 4-amino-4-deoxy-ʟ-arabinose, would thus restore the activity of cationic antimicrobial peptides and several

• mechanisms of pathogenic Gram-negative bacteria against antibiotics, such as polymyxin B and colistin [3]. The main effect of Ara4N incorporation into the lipid A part – and, less frequently, into the inner core region of LPS [4] – is thought to originate from blocking the electrostatic interaction of

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

• , in particular orthopedic implant-related infections, since implants coated with proteins facilitate bacterial attachment and biofilm development [1]. In general, bacteria are known to employ different strategies to cope with the presence of antibiotics, of which a biofilm, an aggregate of

• microorganisms held together within a self-produced matrix of extracellular polymeric substances, plays an important role as a main virulence determinant in staph infections [1][2]. Within a biofilm, bacteria become tolerant toward antibiotics and host immune responses greater than their planktonic (free

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• sponges in massive amounts leads to environmental disturbance since marine sponges play a key role in building coral reefs [3][4]. As a filter feeder, sponges host an enormous amount of microorganisms including algae, bacteria, actinomycetes, and fungi [5][6][7]. Many of these microorganisms produce

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

• has been observed in many cases that exogenous substrates can be incorporated by bacteria into biosynthesis cascades of natural products. The use of substrates which lead to nonnatural derivatives of the natural product coined the field of mutasynthesis, e.g., siderophore analogue biosynthesis by P

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• knowledge of how they are biosynthesized is limited, particularly when compared to the well-studied thiotemplate assembly lines. Bacteria have only recently been recognized as having the genetic potential to biosynthesize a large number of complex terpenoids, but our current ability to associate genetic

• placed on terpene pathways from bacteria, as their biosynthetic pathways usually have the genes encoding the terpene cyclase and modifying enzyme in close proximity, which simplifies both analysis and pathway engineering. The review will begin with a brief description of terpene families with a special

• reported [40]. In fact, different pathways have evolved in plants, fungi, and bacteria for this fascinating compound family in an extreme case of convergent evolution [41][42]. While the plant and fungal biosynthetic pathways are well studied [42], the bacterial pathway was studied to a lesser degree until

Emission and biosynthesis of volatile terpenoids from the plasmodial slime mold Physarum polycephalum

• Xinlu Chen,
• Tobias G. Köllner,
• Wangdan Xiong,
• Guo Wei and
• Feng Chen

Beilstein J. Org. Chem. 2019, 15, 2872–2880, doi:10.3762/bjoc.15.281

• communication [1][2]. Rapid progress has been made in our understanding of the VOC world of microbes, especially bacteria [3][4] and fungi [5][6]. Not only the chemical diversity of microbial VOCs is continuingly to be discovered, our understanding of their biosynthesis is also growing rapidly [7][8]. Among the

• ]. The MVA pathway is found in eukaryotes, archaea, and a few bacteria, and the MEP pathway is present in several photosynthetic eukaryotes and bacteria [11]. Isoprenyl diphosphate synthases (IDSs) catalyze the formation of prenyl diphosphates of various chain length [12]. After that, terpene synthases

• and gene expression patterns, the products of most DdTPSs were released as volatiles from D. discoideum at the multicellular developmental stage [14][15]. TPS genes previously were known to exist only in bacteria, fungi, and plants [13][17][18]. The identification of TPS genes in dictyostelid social

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

• antimicrobial, cytotoxic, and nematicidal activities, as described in the Experimental section. However, compounds 1–5 were devoid of activity in these assays, whereas tyromycin A (6) and skeletocutin A–L had been reported before to be active against several Gram-positive bacteria [4], namely Bacillus subtilis

• determined in serial dilution assays using several microorganisms, as described previously [8][9]. Herein, Gram-positive bacteria used were B. subtilis DSM10, MRSA DSM11822, S. aureus DSM346, M. luteus DSM20030, and Mycobacterium smegmatis (M. smegmatis) ATCC700084, Gram-negative bacteria were Escherichia

• albicans (C. albicans) DSM1665 were applied. The assays were conducted in 96-well plates and Mueller–Hinton Broth (MHB) for bacteria, or yeast, malt, and gluocse (YMG) medium for filamentous fungus and yeasts. Cytotoxicity assay In vitro cytotoxicity, using IC50 values as a measure, was evaluated against

Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

• Heather J. Lacey,
• Cameron L. M. Gilchrist,
• Andrew Crombie,
• John A. Kalaitzis,
• Daniel Vuong,
• Peter J. Rutledge,
• Peter Turner,
• John I. Pitt,
• Ernest Lacey,
• Yit-Heng Chooi and
• Andrew M. Piggott

Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256

• bacteria, fungi, mammalian cells and plants. Bioinformatics analysis, including comparative analysis with other acyl drimenol-producing Aspergilli, led to the identification of a putative nanangenine biosynthetic gene cluster that corresponds to the proposed biosynthetic pathway for nanangenines. Keywords

• cell lines, two bacteria, one fungus and one plant (Table 4). Compound 1 was inactive up to 100 μg mL−1 in all of the assays performed, suggesting acylation at 6-OH is important for biological activity. Compounds 4, 5 and 7 showed moderate antibacterial activity against B. subtilis, with weaker

Chemical synthesis of the pentasaccharide repeating unit of the O-specific polysaccharide from Escherichia coli O132 in the form of its 2-aminoethyl glycoside

• Debasish Pal and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2019, 15, 2563–2568, doi:10.3762/bjoc.15.249

• play a key role in determining and regulating the biology of these organisms [1] and act as the elicitor of the innate immune response [2]. As these polysaccharides can protect the bacteria concerned by killing the serum complements of the host system and can stop phagocytosis, they are extremely

• bacteria present in the guts of human and other warm-blooded animals. It is usually harmless and beneficial to the host’s body, however, there are other variants of E. coli having virulence factors and causing diseases like diarrhea, urinary tract infection, septicaemia etc. E. coli O132 is reported to be

Synthesis of novel sulfide-based cyclic peptidomimetic analogues to solonamides

• José Brango-Vanegas,
• Luan A. Martinho,
• Lucinda J. Bessa,
• Andreanne G. Vasconcelos,
• Alexandra Plácido,
• Alex L. Pereira,
• José R. S. A. Leite and
• Angelo H. L. Machado

Beilstein J. Org. Chem. 2019, 15, 2544–2551, doi:10.3762/bjoc.15.247

• reported for solonamides. Keywords: antivirulence drug; bacteria; macrocyclization; pathoblocker; quorum quenching; Introduction The cyclodepsipeptides called solonamides A and B are natural molecules extracted from the marine bacterium Photobacterium halotolerans [1][2] (Figure 1). They are able to

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

• an α-helical bundle fold [18] and are structurally related to the isoprenyl diphosphate synthases such as the farnesyl (C15) or geranylgeranyl (C20) diphosphate synthase, which generate the substrates of sesqui- and diterpene synthases, respectively. In bacteria, diterpene synthases almost

• description of the bacterial TPS CotB2, we will therefore refer to the NSE motif only. Using host microorganisms, such as bacteria or baker’s yeast for the heterologous synthesis of terpenes increases the sustainability of bioactive terpene production by saving resources, as the production host can be fed

• enzymes that is widely distributed among plants, fungi and bacteria. CotB2 has evolved to convert the acyclic, achiral substrate GGDP to the 5–8–5 ring motif of cyclooctat-9-en-7-ol that contains six chiral stereocenters. Hence, CotB2 has been fine tuned to perform a highly specific regio- and

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• . Compound 1 showed weak growth inhibition against Saccharomyces cerevisiae. Keywords: biosynthesis; fatty acid; marine bacteria; methylation; Microbulbifer; Introduction Marine microbial symbionts are currently recognized as a reservoir of new bioactive compounds [1]. The most well-studied host animal is

• the sponge from which a vast array of natural products has been isolated and symbiotic bacteria are suggested to be responsible for the biosynthesis of such natural products [2]. Although it is well established that corals are associated with diverse microbes, coral-associated bacteria and their

• secondary metabolites have received lesser attention [3]. To date, a couple of new compounds were discovered from soft coral-associated bacteria such as pseudoalteromones from Pseudoalteromonas isolated from the cultured octocoral Lobophytum crassum [4][5] and macrolactin V from Bacillus amyloliquefaciens

Isolation of fungi using the diffusion chamber device FIND technology

• Benjamin Libor,
• Henrik Harms,
• Stefan Kehraus,
• Ekaterina Egereva,
• Max Crüsemann and
• Gabriele M. König

Beilstein J. Org. Chem. 2019, 15, 2191–2203, doi:10.3762/bjoc.15.216

• play a prominent role as lead structures in drug discovery [1]. Apart from bacteria, fungi are an impressive group of microorganisms in this respect, due to the high structural diversity of their rich secondary metabolism. Fungi are known as producers of many therapeutically important drugs, such as

• For the isolation of fungal strains from terrestrial and marine environments a device was constructed, i.e., FIND that is similar to the one described by Epstein et al. for “unculturable” bacteria [4]. For the FIND we adjusted the isolation procedure and technical features, e.g., the dimensions of the

• volume of a sample is experimentally hard to determine. We thus counted bacterial cells, and applied the ratio of bacteria-to-fungi, which is described in the literature for most environments, to estimate suitable dilution or concentration steps in our experiments. Scheme 2 illustrates each individual

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• apoptotic cells, the investigation of the morphology of nuclei, the direct counting of cultivable bacteria, DNA intercalators, etc. [1][2][3][4]. Pyrrole, another biologically active heterocyclic compound, when fused with acridines affords promising bioactive pyrroloacridinone moieties demonstrating