Total synthesis of elansolids B1 and B2

• Liang-Liang Wang and
• Andreas Kirschning

Beilstein J. Org. Chem. 2017, 13, 1280–1287, doi:10.3762/bjoc.13.124

• bacterium Chitinophaga sancti. They show antibacterial activity against Gram-positive bacteria. A second generation total synthesis of the antibiotic elansolid B1 (2) and the first synthesis of elansolid B2 (3) are reported. In contrast to previous work, the (Z,E,Z)-triene at C10–C15 was assembled by using

New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized

• Maryna V. Murlykina,
• Maryna N. Kornet,
• Sergey M. Desenko,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Aleksander A. Brazhko,
• Vladimir I. Musatov,
• Erik V. Van der Eycken and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2017, 13, 1050–1063, doi:10.3762/bjoc.13.104

• obtained were evaluated for their antibacterial activity and several of them demonstrated a weak antimicrobial effect, but for most of the compounds a 30–50% increase in biomass of Gram-positive strains (mainly B. subtilis) compared to control was observed. Keywords: 3-amino-5-methylisoxazole; 5-amino-N

• -aryl-1H-pyrazole-4-carboxamides; antibacterial activity; Groebke–Blackburn–Bienaymé reaction; isocyanide Ugi reaction; Introduction An intensive progress in pharmaceutical and medicinal chemistry, as well as in the generation and improvement of medicinal technologies has led to defeating a wide scope

• compound 9e (Figure 5). Antibacterial activity The antibacterial activity of compounds 4, 6 and 9 (Table 7) was studied (see Experimental part in Supporting Information File 1 for details) against reference bacterial cultures: Bacillus subtilis (strain 1211), Staphylococcus aureus (strain 2231) (Gram

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• antibacterial activity against Escherichia coli and Bacillus subtilis, and antifungal activity against Aspergillus niger and Penicillium notatum. Among the synthesized series of 1-indanone derivatives 64, the highest antibacterial activity was exhibited by derivatives 64k and 64l, whereas the most potent

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• -positive bacteria, including resistant strains [2][9][20] and Mycobacterium species [21]. No activity was observed against Gram-negative bacteria (except for Neisseria gonorrhoeae), fungi or yeast [9]. The antibacterial activity arises through inhibition of cell wall synthesis [22] by prevention of

• bacteria [7] with the primary cellular target deduced to be bacterial cell wall synthesis [34]. Extensive derivatisation of both mannopeptimycin α (12) and β (13) was undertaken to improve the antibacterial activity of the parent natural products (highlighted in blue, Figure 6). An array of ether [35][36

• ], halogenated [36], acetal [37][38][39], benzoxazole [40], thiobenzoxazole [40], ester and carbonate [41] analogues were synthesised and evaluated for antibacterial activity. Only the semisynthetic derivatives possessing hydrophobic groups on the terminal sugar moiety (green) exhibited comparable antibacterial

Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

• Peng Zhang,
• Xiao-Ming Li,
• Xin-Xin Mao,
• Attila Mándi,
• Tibor Kurtán and
• Bin-Gui Wang

Beilstein J. Org. Chem. 2016, 12, 2012–2018, doi:10.3762/bjoc.12.188

• prolific source of bioactive secondary metabolites of diverse structures, including, for example, semiviriditoxin derivatives with antibacterial activity [3], cornexistin and hydroxycornexistin with herbicidal activity [4], and paecilocins with antibacterial activity [5]. During our ongoing effort to

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

• carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds

• residue, which in turn, is connected to the ureido dipeptide L-Phe-L-Val. The compound showed antifungal and antibacterial activity against Mucor hiemalis and Staphylococcus aureus with a MIC of 32 and 16 μg/mL, respectively [2]. Compounds containing the isomeric 2,4-pyrrolidinedione ring system (tetramic

• µg/mL for both molecules (see Supporting Information File 2 for details). The antibacterial activity shown by both compounds suggests that they can be considered as promising candidates for further developments. Conclusion In conclusion, leopolic acid A was obtained for the first time in a 11-step

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• groups. Besides a common antibacterial activity, many tetronates also have further attractive bioactivities that triggered interest in their research [139][140]. Tetronates and their biosynthesis have recently been extensively reviewed and a classification based on structural characteristics was devised

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• (alternatively named lantipeptides [44]) are large bacterial RiPPs, and the first member to be reported was nisin (Figure 4A) from Lactococcus lactis in 1928 [45]. Many members of this family have antibacterial activity and these are termed lantibiotics [46]; nisin itself is used as a food preservative as it

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

• . Fluorine-substituted flavonoids were found to be less active than those bearing other halogen atoms. Keywords: antibacterial activity; dithiocarbamates; dithiolium salts; flavonoids; SAR studies; Introduction The extensive use of antibiotics in human treatment and agriculture has led to the development

• nature of the dialkylamino moiety at the 2 position of ring D. After the best correlation between the antibacterial activity and the nature of the dialkylamino moiety had been identified as the N,N-diethylamino group, this substituent was maintained, while the structure–activity study was extended to

• the heterocyclic ring in 5a. In vitro antibacterial activity The promising results obtained in our previous studies [13][27] prompted us to investigate to what degree the amino moiety and the two halogen atoms bound to tricyclic flavonoids of type 5 influence their antibacterial activity. This study

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

• 16 was neither a good substrate nor an inhibitor of this enzyme, hence explaining its lack of antibacterial activity towards E. coli. On the other hand, compound 16 was found to inhibit the growth of Plasmodium falciparum with an IC50 value of 60 ± 11 μM (n = 3) in the absence of pantetheinase

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• activity against Gram-positive bacteria was observed, but it displayed pronounced antibacterial activity against P. aeruginosa. This remarkable finding distinguishes the mureidomycins, pacidamycins, sansanmycins and napsamycins from other nucleoside antibiotics. On the other hand, caprazamycin B shows good

• μg/mL and 4 μg/mL. Derivatives with unnatural D-stereochemistry in the pentadecyl glycine motif possessed a similar antibacterial activity (potency within factor 2). Truncated analogues lacking the L-valine urea terminus (Cbz-protected 92d and N-terminally unprotected 92e) showed only a minor loss of

• central leucine unit and the terminal truncation had no crucial effects on the antibacterial activity (Table 2). Truncated derivatives 92f–h (Figure 10) without the L-valine urea terminus contained L-ornithine (L-Orn, 92f), L-arginine (L-Arg, 92g) and L-methionine (L-Met, 92h), respectively. They were

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

• bioactivity data of the disciformycins suggests that the isovalerate motive is important for the antibacterial activity. Due to their potent effects against human pathogenic staphylococci as well as negligible toxicity, gulmirecins A and disciformycin B have become promising candidate compounds for the design

• a restricted prey spectrum [82]. Regarding the available information on the chemistry of predatory myxobacteria, it seems likely that every strain has the potential to produce at least a single class of natural products with potent antibacterial activity. The high recovery rate of myxovirescins and

Studies on the synthesis of peptides containing dehydrovaline and dehydroisoleucine based on copper-mediated enamide formation

• Franziska Gille and
• Andreas Kirschning

Beilstein J. Org. Chem. 2016, 12, 564–570, doi:10.3762/bjoc.12.55

• of myxovalargin (1), a secondary metabolite from Myxococcus fulvus with antibacterial activity [14][15], we report on copper-mediated cross-coupling chemistry to create peptide fragments bearing dehydrovaline and dehydroisoleucine. We faced difficulties to use the reported conditions for the C–N

A selective and mild glycosylation method of natural phenolic alcohols

• Mária Mastihubová and
• Monika Poláková

Beilstein J. Org. Chem. 2016, 12, 524–530, doi:10.3762/bjoc.12.51

• -glucopyranoside (vanillyl β-D-glucoside, 1) isolated from the exocarp of Juglans mandshurica Maxim showed antibacterial activity [1]. A wide range of pharmacological effects, e.g., anti-oxidant, anti-inflammatory, anticancer, hepatoprotective, cardioprotective, neuroprotective, antidiabetic, and antiviral

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• binding affinity [21], inhibition of hepatic cholesterol [22], inhibition of aldose reductase [23], antiproliferative [24], antiviral, cytotoxic [25], antifungal [26], anti-HIV [27][28][29] and antibacterial activity [30]. Although rare, there are a few natural products, for example, melanervin (5), a

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

• phenyl ring. They contain several additional H-bond donor and acceptor functions at the terminal N-glycinyl position [45]. This class of compounds shows moderate to potent antibacterial activity against staphylococcal and enterococcal strains. Though both candidates differ just by a single methyl

Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones

• Srinivas Thadkapally,
• Athira C. Kunjachan and
• Rajeev S. Menon

Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3

• cell death [4]. The natural chromene rhodomyrtone (Figure 1) is known to exhibit potent antibacterial activity [5]. As a consequence, a number of methods have been developed for the synthesis of substituted 4H-chromenes [6]. This includes, inter alia, transition metal-mediated cyclizations [7

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• a large group of structurally diverse secondary metabolites. Among these natural products, Xenia diterpenoids or xenicanes represent a unique family with intriguing structural features and diverse biological activities. Many xenicanes display significant cytotoxic and antibacterial activity and are

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

• substituents such as cholesterol and quinoline hindered the complete reductive debenzylation, at least under the described conditions. Biology The antibacterial activity of selected newly synthesized cholesterol conjugates was evaluated in vitro against E.coli (ATCC 11775) and S. aureus (ATTC 12600) according

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

• 95; 9H-furo[2,3-b]pyrido[4,3,2-mn]acridin-9-one, 96) related to that of ascididemin (42) [70] also displayed antibacterial activity two-fold lower than that of 42 and 89. Nevertheless, both 95 and 96 remain good candidates such as 89 to be explored. Considering the cytotoxicity of 42, 89, 95 and 96

• antibacterial potency of 10- and 30-fold for E. coli and M. luteus, respectively, was observed when the E ring contains an OH group (97). A similar decrease in potency was observed when the same ring is a dihydropyridone and ring A contains an OH group (33). No further improvement in the antibacterial activity

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• investigations have shown that beside their antibacterial activity, some macrolides exhibit anti-inflammatory/immunomodulatory [5][6][7][8][9][10], antitumor [11][12][13], antiviral [10] or antimalarial [14][15] activity. These discoveries have sparked a new interest in the structural modification of macrolides

A new and efficient procedure for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones

• Marcelo Isidoro P. Reis,
• Vinícius R. Campos,
• Jackson A. L. C. Resende,
• Fernando C. Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2015, 11, 1235–1240, doi:10.3762/bjoc.11.137

• N,S-acetals. These compounds were obtained in good yields, and several of them showed promising antibacterial activity [42]. The structures of the synthesized 1,3,5-triazinanes were confirmed by spectroscopic techniques such as NMR, 1H and 13C-APT, infrared spectroscopy (FTIR) and high resolution

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

• their high thermal stability, low toxicity to human cells and effective broad-spectrum antibacterial activity. The antibacterial activity of these nanoparticles is probably due to their rapid breakdown which releases ionic silver that interact with the thiol residues of bacterial enzymes [80]. As a

• diameter of the capped particles was smaller than uncapped ones (up to 3-fold). Moreover, these nanoparticles have superior photostability to intense ultraviolet radiation and significantly higher antibacterial activity (up to 3.5-fold) were obtained against E. coli, P. aeruginosa and S. aureus. As the β

• mechanism is the same as that of Jaiswal et al. (see Scheme 9) [84]. In 2010, Bajpai et al. loaded silver ions (Ag+) on CD-grafted onto cotton fabric to achieve an antimicrobial property [88]. A correct antibacterial activity was obtained against E. coli and the release of silver ions was observed for a

De novo macrolide–glycolipid macrolactone hybrids: Synthesis, structure and antibiotic activity of carbohydrate-fused macrocycles

• Richard T. Desmond,
• Anniefer N. Magpusao,
• Chris Lorenc,
• Jeremy B. Alverson,
• Nigel Priestley and
• Mark W. Peczuh

Beilstein J. Org. Chem. 2014, 10, 2215–2221, doi:10.3762/bjoc.10.229

• antibacterial activity [7][8]. Over time, antibiotic use has created a selection pressure that has led to bacterial resistance and a subsequent need for continuous development of new antibiotics. Despite cumbersome syntheses, erythromycin analogs continue to be used as front line antibiotics while the clinical

• ]. Conclusion We have described the synthesis and characterization of de novo macrolide 16 as a member of a family of related macrocyles that fuse a pyranose monosaccharide to the macrocyclic ring. The new compounds showed modest antibacterial activity against Gram positive organisms. The main conclusion of the

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• tricyclic intermediate 121. Cleavage of the TBS ethers and hydrogenolysis of the benzyl ester in presence of amidine 122 yielded trinem 23a as its amidinium salt 123. Trinem 123 exhibited antibacterial activity against a variety of strains, with MIC’s of 1.0 μg/mL against Staphylococcus aureus 853E and 0.1

• μg/mL against Streptococcus pneumoniae 3512. The antibacterial activity of 123 was considerably weaker compared to imipenem (111) and sanfetrinem (113), which showed MIC’s of 0.06 and 0.2 μg/mL, respectively, against S. aureus and 0.01 μg/mL against S. pneumoniae. The lack of potency of 123 was