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

• potential alternative to traditional antibiotics. To date, a very large number of antimicrobial peptides have been produced based on naturally occurring products or by de novo design, and most of them display a broad spectrum of antimicrobial activities [3][4]. Despite their remarkable structural diversity

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

• ; medicinal organometallic chemistry; metallocenoyl; peptides; tryptophan; Introduction New antibacterial agents need to be discovered since established antibiotics are increasingly losing ground against resistant bacteria and at the same time the pipeline that is supposed to produce new antibiotics is

Synthetic studies towards bottromycin

• Stefanie Ackermann,
• Hans-Georg Lerchen,
• Dieter Häbich,
• Angelika Ullrich and
• Uli Kazmaier

Beilstein J. Org. Chem. 2012, 8, 1652–1656, doi:10.3762/bjoc.8.189

• ring system in a straightforward manner. Keywords: amidines; antibiotics; bottromycin; peptides; thiopeptides; Ugi reactions; Introduction Natural products are excellent sources as lead structures for the development of new antibiotics. Over millions of years microorganisms, such as bacteria and

• fungi, developed efficient defense strategies against their bacterial competitors [1][2][3]. Not surprising, a wide range of common antibiotics such as penicillin or vancomycin are natural products or derivatives thereof. In 1957 Waiswisz et al. reported a new antibiotic peptide isolated from the

• fermentation broth of Streptomyces bottropensis, called bottromycin [4][5][6]. This antibiotic inhibits the growth of a wide range of microorganisms by interfering with their protein biosynthesis [7][8][9][10][11][12]. In 1965 Nakamura et al. isolated closely related antibiotics from the strain Streptomyces No

Asymmetric one-pot sequential Friedel–Crafts-type alkylation and α-oxyamination catalyzed by a peptide and an enzyme

• Kengo Akagawa,
• Ryota Umezawa and
• Kazuaki Kudo

Beilstein J. Org. Chem. 2012, 8, 1333–1337, doi:10.3762/bjoc.8.152

• ][19][20]. Indoles with an oxygenated stereogenic carbon at the β-position of the ring, such as indolmycin [21][22] and diolmycin [23], are known as antibiotics (Figure 1). The framework of these compounds could be constructed though the conjugate addition of an indole to α,β-unsaturated aldehydes

Binaphthyl-anchored antibacterial tripeptide derivatives with hydrophobic C-terminal amino acid variations

• John B. Bremner,
• Paul A. Keller,
• Stephen G. Pyne,
• Mark J. Robertson,
• K. Sakthivel,
• Kittiya Somphol,
• Dean Baylis,
• Jonathan A. Coates,
• John Deadman,
• Dharshini Jeevarajah and
• David I. Rhodes

Beilstein J. Org. Chem. 2012, 8, 1265–1270, doi:10.3762/bjoc.8.142

• antibiotics [1][2], and of particular concern is the resistance to the cationic glycopeptide, vancomycin [3][4]. This challenge is being addressed in a number of ways, which include both detailed studies aimed at the further understanding of the mechanism of this resistance, as well as the development of new

Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

• Evan F. Haney,
• Leonard T. Nguyen,
• David J. Schibli and
• Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

• ; NMR solution structure; membrane interactions; peptides structure–function relationship; Introduction Antimicrobial peptides (AMPs) continue to attract significant attention as potential alternatives to conventional antibiotics. A large number of AMP sequences have been reported in the literature

• experiments. This work was supported by the Canadian Institutes of Health Research program for “Novel Alternatives to Antibiotics”. HJV is an Alberta Innovates – Health Solutions Scientist.

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

Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

• Workalemahu M. Berhanu,
• Mohamed A. Ibrahim,
• Girinath G. Pillai,
• Alexander A. Oliferenko,
• Levan Khelashvili,
• Farukh Jabeen,
• Bushra Mirza,
• Farzana Latif Ansari,
• Ihsan ul-Haq,
• Said A. El-Feky and
• Alan R. Katritzky

Beilstein J. Org. Chem. 2012, 8, 1146–1160, doi:10.3762/bjoc.8.128

• ; Introduction Diverse cyclic peptides, both natural and synthesized, are potent antibiotics [1][2][3]. Gramicidin S, vancomycine, bacitracin, polymixin B, colistin, valinomycin, actinomycin, and many more, have been tested and used clinically as antimicrobial and antifungal agents: It is believed that cyclic

• antibiotics roxithromycin and cefixime were used as positive controls. It is seen that peptidomimetic 37b exhibits moderate activity against Bordetella bronchiseptica, Micrococcus luteus, and Salmonella typhimurium. For a “bare” scaffold with no tailor-made substitution, this should be considered as an

Antibiotic and cytotoxic peptides

• Norbert Sewald

Beilstein J. Org. Chem. 2012, 8, 1144–1145, doi:10.3762/bjoc.8.127

• Journal of Organic Chemistry on “Antibiotic and cytotoxic peptides”: The fight against bacterial infections is in a critical phase. The excessive application of antibiotics in human therapy, and also in livestock breeding, leads to the rapid development of highly virulent bacterial strains resistant to

• the conventionally applied antibiotics. Consequently, the search for new antibiotically active compounds is of premier importance. On the other hand, highly cytotoxic peptides and peptide analogues, such as monomethyl auristatin E, are used as the “warhead” in antibody–drug conjugates for tumor

Unprecedented deoxygenation at C-7 of the ansamitocin core during mutasynthetic biotransformations

• Tobias Knobloch,
• Gerald Dräger,
• Wera Collisi,
• Florenz Sasse and
• Andreas Kirschning

Beilstein J. Org. Chem. 2012, 8, 861–869, doi:10.3762/bjoc.8.96

• . Keywords: ansamitocins; antibiotics; antitumor agents; mutasynthesis; natural products; Introduction Natural products still play an important role as lead structures for the treatment of infectious diseases and cancer. However, natural products have lost some of their attraction for the development of

• multienzymes are responsible for setting up the complete carbon backbone of both ansamycin antibiotics [21][22][23][24]. More precisely, the biosynthesis of ansamitocins relies on a type I modular polyketide synthase (PKS), with 3-amino-5-hydroxybenzoic acid (1, AHBA) [20] as the starter unit followed by chain

Synthesis and biological evaluation of nojirimycin- and pyrrolidine-based trehalase inhibitors

• Davide Bini,
• Francesca Cardona,
• Matilde Forcella,
• Camilla Parmeggiani,
• Paolo Parenti,
• Francesco Nicotra and
• Laura Cipolla

Beilstein J. Org. Chem. 2012, 8, 514–521, doi:10.3762/bjoc.8.58

• potential fungicides or antibiotics [13], such as trehalostatin (4) [1][14] and some iminosugar glycoconjugates, e.g., 5 or MDL 25,637 (6) [1][15][16] (Figure 1). In this work we report the synthesis and the biological activity of a small set of nojirimycin- and pyrrolidine-based iminosugar derivatives and

Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663

• Orwah Saleh,
• Katrin Flinspach,
• Lucia Westrich,
• Andreas Kulik,
• Bertolt Gust,
• Hans-Peter Fiedler and
• Lutz Heide

Beilstein J. Org. Chem. 2012, 8, 501–513, doi:10.3762/bjoc.8.57

• shown to increase the production of certain antibiotics [14]. Of each mutant obtained in this study, usually three independent clones were isolated, and secondary metabolite production was determined in three parallel cultivations for each clone. The variability of production between different clones

• well as the so-called cpk cluster, have been deleted, and which also lacks plasmids SCP1 and SCP2. Furthermore, strain M1154 was generated from strain M1146 by introducing mutations into the genes rpoB and rpsL, which has been shown to result in an increased production of certain antibiotics [15]. We

Aldol elaboration of 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridin-4-ones, masked precursors to acylpyridones

• Raymond C. F. Jones,
• Abdul K. Choudhury,
• James N. Iley,
• Mark E. Light,
• Georgia Loizou and
• Terence A. Pillainayagam

Beilstein J. Org. Chem. 2012, 8, 308–312, doi:10.3762/bjoc.8.33

• elfamycin antibiotics [5]. Interest has also been stimulated in these metabolites by the use of the entomopathogenic fungi such as Cordyceps sp., many of which contain pyridone metabolites, in traditional Chinese medicine to strengthen the immune system and improve cognitive function. Farinosone A (2d) from

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

• Jeroen S. Dickschat,
• Hilke Bruns and
• Ramona Riclea

Beilstein J. Org. Chem. 2011, 7, 1697–1712, doi:10.3762/bjoc.7.200

• genus includes producers of important antibiotics such as the aminoglycoside gentamycin [15] and the antitumor antibiotics lomaiviticins A and B (Micromonospora lomaivitiensis) [16]. Here the results of the headspace analyses of M. aurantiaca are described. Besides compounds from other classes, several

Tertiary alcohol preferred: Hydroxylation of trans-3-methyl-L-proline with proline hydroxylases

• Christian Klein and
• Wolfgang Hüttel

Beilstein J. Org. Chem. 2011, 7, 1643–1647, doi:10.3762/bjoc.7.193

• , proline hydroxylases exclusively hydroxylate the free L-amino acid and are limited to some bacteria and filamentous fungi. As far as it is known, they are involved in secondary metabolism, for example, in the biosynthesis of the non-ribosomal peptide antibiotics etamycin, telomycin and pneumocandin [22

Biosynthesis and function of secondary metabolites

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2011, 7, 1620–1621, doi:10.3762/bjoc.7.190

• hundreds of possible examples. Finding new secondary metabolites is a prerequisite for the development of novel pharmaceuticals, and this is an especially urgent task in the case of antibiotics due to the rapid spreading of bacterial resistances and the emergence of multiresistant pathogenic strains, which

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• previously suggested intermediate II (Scheme 1). The synthetic utility of these cycloadditions has also been explored, and recently an intramolecular version was applied to the synthesis of the angucyclinone antibiotics, (+)-ochromycinone and (+)-rubiginone B2 [29][30][31][32]. Closely related dipolar

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• ][38][39][40][41][42][43][44] (akin to such well-known DNA cleavers as enediyne antibiotics) [45][46] or C1–C5 cyclization [47][48][49][50][51][52] (Figure 2). In the latter process, which transforms enediynes into indenes, four hydrogens are transferred from the environment (two as H-atoms and two as

Synthesis of fluorinated δ-lactams via cycloisomerization of gem-difluoropropargyl amides

• Satoru Arimitsu and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2010, 6, No. 48, doi:10.3762/bjoc.6.48

• -difluoromethylene moiety has been reported to improve their biological activities. For example, a gem-difluoro-γ-lactam can inhibit γ-lactamase, which is responsible for bacterial resistance to γ-lactam antibiotics [2][3][4]. Additionally, α,α-difluoro lactams are precursors of some biologically active compounds [5

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• derivatives with tendency to adopt specific compact conformations (foldamers). Linear naturally-occurring SAA homo-oligomers SAAs occur extensively in nature as subunits of oligosaccharides in cell walls such as N-acetylneuraminic 1 and muramic acids 2, as well as in some nucleoside antibiotics (e.g

• interest because these functional groups are isosteric with phosphodiesther groups occurring in oligoglycosylphosphates and nucleotides. Some examples of natural compounds having saccharide units connected by pseudoamide linkage are known. For example, the family of glycocinnamoylspermidine antibiotics 26

• relationships in order to design novel biologically active analogues of potential therapeutic value. Schematic representation of sugar aminoacids (SAAs) and (pseudo)amide oligosaccharide mimetics. Natural SAAs structures and natural nucleosidic antibiotics. The general structure of glycoamino acids and their

Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration

• Latif Kelebekli,
• Yunus Kara and
• Murat Celik

Beilstein J. Org. Chem. 2010, 6, No. 15, doi:10.3762/bjoc.6.15

• of carbohydrate mimetics, which can be potent inhibitors of glycosidase (1–4) [11][12][13][14][15][16], we have developed a method for rapid entry to these compounds. Antibiotics containing an aminocyclitol unit have stimulated the development of synthetic methodologies [16] in the search for

Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides

• Ana Maria Castilla,
• M. Morgan Conn and
• Pablo Ballester

Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5

• dipeptide, the common target for the vancomycin antibiotics. This group of antibiotics is active against certain aerobic and anaerobic Gram-positive bacteria, and has been used for many years as treatment of last resort in clinical wards [2][3][4]. However, vancomycin resistance has recently been identified

• take place during vancomycin action, but also because the structures of the most efficient receptors prepared might be useful as scaffolds for future antibiotics. Herein, we report the design and synthesis of two new macrocyclic receptors, 1 and 2, conceived for the binding of dipeptides, in particular

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• ), D-glucosamine 21 and carbamoyl phosphate (Scheme 4) [29][30][31][32]. The key intermediate, AHBA, is also a common precursor to other anticancer drugs, such as rifamycin and ansamycin. 2.2. Mode of action Mitomycins are quinone antitumor antibiotics that exert their biological activity through DNA

Sordarin, an antifungal agent with a unique mode of action

• Huan Liang

Beilstein J. Org. Chem. 2008, 4, No. 31, doi:10.3762/bjoc.4.31

• immunosuppressed patients, especially those suffering from AIDS or cancer, fungal infections have become a significant, often life-threatening problem [1][2]. Present treatments rely on antifungals such as polyene antibiotics (amphotericin B), nucleoside analogs (5-fluorocytosine) and azoles (fluoconazole