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Journal of Antibiotics

Chang Lu, Yue Zhao, Wei-Qi Jia, Hui Zhang, Huan Qi, Wen-Sheng Xiang, Ji-Dong Wang, Xiang-Jing Wang
A new anthracycline-type metabolite, designated as tetracenoquinocin A (1), was isolated from the fermentation broth of Streptomyces sp. NEAU-L3. Its structure was determined on the basis of spectroscopic analysis, including 1D and 2D NMR techniques as well as ESI-MS and comparison with data from the literature. Compound 1 showed potent cytotoxic activity against three cancer cell lines (HepG2, A549, HCT-116) with IC50 values of 5.57, 24.30 and 20.82 μM, respectively.The Journal of Antibiotics advance online publication, 16 August 2017; doi:10...
August 16, 2017: Journal of Antibiotics
Yuki Hirota-Takahata, Yoko Ishimoto, Emi Kurosawa, Yuko Iwadate, Yoshiko Onozawa, Isshin Tanaka, Masahiro Tanaka, Hideki Kobayashi
In the course of our screening program for vasoactive compounds using co-culture assay of endothelial cells and fibroblast cells, potent activity was detected in the cultured broth of Incrucipulum sp. SANK 10414. Two active compounds, F-36316 A and B, and a non-active homolog, F-36316 C, were isolated from the broth. The structures of F-36316 A, B and C were elucidated by physicochemical data and spectral analyses, and found to be new 3-acylated tetronic acid homologs. F-36316 A and B induced morphological changes of endothelial cells different from vascular endothelial growth factor (VEGF) or vestaines in the assay with EC50 values of 1...
August 9, 2017: Journal of Antibiotics
Shuichi Hagihara, Kengo Hanaya, Takeshi Sugai, Mitsuru Shoji
Englerin A, a guaiane sesquiterpene isolated from Phyllanthus engleri, showed highly potent and selective growth inhibitory activities against renal cancer cell lines. We synthesized the key tricyclic intermediate from commercially available 2,2-dimethyl-1,3-dioxan-5-one via regio- and diastereoselective [4+3] cycloaddition between the formyl enol silyl ether and the disubstituted furan, in 4.8% total yield over 10 steps.The Journal of Antibiotics advance online publication, 2 August 2017; doi:10.1038/ja.2017...
August 2, 2017: Journal of Antibiotics
Alasdair Tm Hubbard, Anthony Rm Coates, Richard D Harvey
HT61 and chlorhexidine (CHX) are both putative membrane-active antimicrobials, which non-specifically target the anionic lipids abundant in bacterial membranes. In model systems, the ability of these antimicrobials to partition into lipid monolayers and increase the permeability of lipid bilayers is dependent upon the presence and proportion of anionic lipids such as phosphatidylglycerol. Despite their apparent similarity in membrane affinity, we have found that HT61 and CHX differ in the extent to which they affect membrane integrity...
August 2, 2017: Journal of Antibiotics
Shigeru Kitani, Tatsuya Ueguchi, Yasuhiro Igarashi, Kantinan Leetanasaksakul, Arinthip Thamchaipenet, Takuya Nihira
A new cyclic depsipeptide, rakicidin F (1), along with the known compound rakicidin C (2), was isolated from the fermentation broth of the marine sponge-derived actinomycete strain Streptomyces sp. GKU 220. Their structures were elucidated by interpreting the HRFABMS and NMR spectroscopic data. Rakicidin F (1) showed growth inhibitory activity against bacteria.The Journal of Antibiotics advance online publication, 2 August 2017; doi:10.1038/ja.2017.92.
August 2, 2017: Journal of Antibiotics
Alexander R Rovira, Yitzhak Tor
A set of unique nucleoside analogs, containing 'spirocyclic orthoester-type' scaffolds, were synthesized from a common isothiazolo[4,3-d]pyrimidine-riboside precursor. The key reaction, using 1,2-di-heteroatomic nucleophiles (e.g., 1,2-ethandithiol) and BF3•OEt2, converts an exocyclic imine into the spirocyclic analogs. The novel structural scaffold is confirmed through the use of one- and two-dimensional (1)H and (13)C NMR experiments.The Journal of Antibiotics advance online publication, 26 July 2017; doi:10...
July 26, 2017: Journal of Antibiotics
Cuixiang Sun, Yonghong Deng, Diana K Hunt, Corey Fyfe, Chi-Li Chen, Roger B Clark, Trudy H Grossman, Joyce A Sutcliffe, Xiao-Yi Xiao
A convergent total synthesis platform led to the discovery of TP-2758 from a series of novel 7-methoxy-8-heterocyclyl tetracycline analogs. TP-2758 demonstrated high in vitro potency against key Gram-negative pathogens including extended spectrum β-lactamases- and carbapenemase-producing Enterobacteriaceae and Acinetobacter spp. strains. This compound was efficacious when administered either intravenously or orally in multiple murine infection models and displayed a favorable preclinical pharmacological profile supporting its advancement into clinical development...
July 26, 2017: Journal of Antibiotics
Hideki Hashizume, Yoshiaki Takahashi, Tohru Masuda, Shun-Ichi Ohba, Tomokazu Ohishi, Manabu Kawada, Masayuki Igarashi
Natural lipopeptide antibiotic tripropeptin C (TPPC) revitalizes and synergistically potentiates the activities of the class of β-lactam antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) but not against methicillin-sensitive S. aureus in vitro; however, the mode of action remains unclear. In the course of the study to reveal its mode of action, we found that TPPC inhibited the β-lactamase production induced by cefotiam. This prompted us to focus on the β-lactam-inducible β-lactam-resistant genes blaZ (β-lactamase) and mecA (foreign penicillin-binding protein), as they are mutually regulated by the blaZ/I/R1 and mecA/I/R1 systems...
July 26, 2017: Journal of Antibiotics
Jian Ma, Hui Lei, Xiu Chen, Xiaoxu Bi, Yi Jiang, Li Han, Xueshi Huang
Three new metabolites (2-4), together with one known compound, GTRI-02, (1) were isolated from a fermentation broth of Streptomyces violaceoruber derived from Equus burchelli feces. The structures of the new compounds 2-4 were established using comprehensive NMR spectroscopic data analysis as well as UV, IR and MS data. The anti-inflammatory activity of compounds 1-4 was tested by examining their ability to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells...
July 12, 2017: Journal of Antibiotics
Hideki Yamamura, Shoya Miyazaki, Kodai Ikoma, Youji Nakagawa, Moriyuki Hamada, Misa Otoguro, Tomohiko Tamura, Katsuhiko Ando, Nyunt Phay, Masayuki Hayakawa
An actinomycete strain, designated MM04-1133(T), was isolated from an anthill soil sample collected in Bagan, Myanmar. To establish the taxonomic status of this strain, the isolate was subjected to a polyphasic approach. Strain MM04-1133(T) was Gram-staining positive, aerobic, motile and formed long and narrow sporangia directly above the surface of the substrate mycelium. Whole-cell hydrolysates of the strain contained 3-OH-diaminopimelic acid, arabinose, glucose, galactose, mannose, rhamnose and xylose. The predominant menaquinones were MK-10(H6) and MK-10(H8)...
July 12, 2017: Journal of Antibiotics
Lili Li, Sofie Kromann, John Elmerdahl Olsen, Søren Wedel Svenningsen, Rikke Heidemann Olsen
Sertraline, an antidepressive drug, has been reported to inhibit general bacterial efflux pumps. In the present study, we report for the first time a synergistic effect of sertraline and tetracycline in a TetA-encoded tetracycline-resistant strain of Escherichia coli. Synergy between sertraline and tetracycline in an E. coli strain with TetA-mediated tetracycline resistance (E. coli APEC_O2) was assessed by the MIC and checkerboard assays. The global transcriptome of E. coli APEC_O2 exposed to ½ MIC concentrations of sertraline and/or tetracycline was analyzed to elucidate the interaction mechanism between sertraline and tetracycline...
July 12, 2017: Journal of Antibiotics
Dhanalakshmi R Nair, Ji Chen, João M Monteiro, Michaele Josten, Mariana G Pinho, Hans-Georg Sahl, Jimmy Wu, Ambrose Cheung
In a loss-of-viability screen of small molecules against methicillin-resistant Staphylococcus aureus (MRSA) USA300, we found a small molecule, designated DNAC-2, which has an MIC of 8 μg ml(-1). DNAC-2 is a quinolinol derivative that is bactericidal at 2X MIC. Macromolecular synthesis assays at 2 × MIC of DNAC-2 revealed inhibition of DNA, cell wall, RNA and protein synthesis within fifteen to thirty minutes of treatment when compared to the untreated control. Transmission electron microscopy of DNAC-2-treated cells revealed a significantly thicker cell wall and impaired daughter cell separation...
July 12, 2017: Journal of Antibiotics
Hiroyasu Ando, Aoi Kimishima, Motoyoshi Ohara, Tomoyasu Hirose, Takanori Matsumaru, Hirokazu Takada, Keisuke Morodome, Takehiro Miyamoto, Akihiro Sugawara, Satoshi Ōmura, Toshiaki Sunazuka
Synthesis of a cis-decalin moiety, containing an oxa-bridged cis-decalin ring system (11-oxatricyclo(5.3.1.(1,7)0(3,8))undecane), as a key intermediate of the total synthesis of luminamicin (1) was accomplished. One of the essential steps in our synthetic route is construction of a cis-decaline framework using a one-pot Michael addition-aldol reaction. Additionally, the bridged ether moiety was obtained by an intramolecular 1,6-oxa-Michael reaction of a conjugated aldehyde.The Journal of Antibiotics advance online publication, 5 July 2017; doi:10...
July 5, 2017: Journal of Antibiotics
Zhengkun Chen, Xiuli Xu, Jinwei Ren, Wenzhao Wang, Xingzhong Liu, Erwei Li
Trichopeptides A (1) and B (2), new linear tetrapeptide and tripeptide, respectively, and three new diketopiperazines trichocyclodipeptides A-C (3-5) were isolated from the fermentation of the ascomycete fungus Stagonospora trichophoricola, a fungus isolated from the soil sample surrounding the fruiting body of Ophiocordyceps sinensis in Maqin Country, Qinghai Province, People's Republic of China. Their structures were primarily elucidated by interpretation of NMR and MS experiments. The absolute configurations of 1-5 were assigned through Marfey's method on their acid hydrolyzates...
July 5, 2017: Journal of Antibiotics
Ko Kumura, Yoshinari Wakiyama, Kazutaka Ueda, Eijiro Umemura, Takashi Watanabe, Mikio Yamamoto, Takuji Yoshida, Keiichi Ajito
Lincomycin derivatives that have a 5-(2-nitrophenyl)-1,3,4-thiadiazol-2-yl thio moiety at the 7-position were synthesized. 5-Substituted 2-nitrophenyl derivatives showed potent antibacterial activities against Streptococcus pneumoniae and Streptococcus pyogenes with erm gene. Antibacterial activities of the 4,5-di-substituted 2-nitrophenyl derivatives were generally comparable to those of telithromycin (TEL) against S. pneumoniae with erm gene and clearly superior to those of TEL against S. pyogenes with erm gene...
July 5, 2017: Journal of Antibiotics
Hue Tu Quach, Riho Tanigaki, Junpei Yokoigawa, Yuriko Yamada, Masamitsu Niwa, Seiya Hirano, Yoshihito Shiono, Ken-Ichi Kimura, Takao Kataoka
Allantopyrone A is a fungal metabolite that uniquely possesses two α,β-unsaturated carbonyl moieties. We recently reported that allantopyrone A inhibited the nuclear factor-κB (NF-κB) signaling pathway induced by tumor necrosis factor (TNF)-α in human lung carcinoma A549 cells. In the present study, the mechanism by which allantopyrone A inhibits the TNF-α-induced signaling pathway was investigated in more detail. Allantopyrone A blocked extensive modifications to receptor-interacting protein 1 (RIP1) in the TNF receptor 1 (TNF-R1) complex...
July 5, 2017: Journal of Antibiotics
Kyriacos C Nicolaou, Stephan Rigol
The advent of modern antibiotics contributed enormously to the dramatic extension of human lifespan since their discovery by virtue of their lethal and selective action against pathogenic microbes. And yet despite our powerful arsenal of weapons against these pathogens, the war against them has not been won. And it may never be. Drug resistance is still menacing the society with many lives being lost due to deadly infections caused by continuously evolving strains spread beyond our means to eradicate them or prevent their spreading...
July 5, 2017: Journal of Antibiotics
Brandon Kulengowski, Jeffrey J Campion, David J Feola, David S Burgess
No abstract text is available yet for this article.
July 5, 2017: Journal of Antibiotics
Henki Rotinsulu, Hiroyuki Yamazaki, Tomohito Miura, Satomi Chiba, Defny S Wewengkang, Deiske A Sumilat, Michio Namikoshi
No abstract text is available yet for this article.
June 28, 2017: Journal of Antibiotics
Yoshiaki Takahashi, Eijiro Umemura, Yoshihiko Kobayashi, Shoichi Murakami, Toru Nawa, Akihiro Morinaka, Toshiaki Miyake, Masakatsu Shibasaki
No abstract text is available yet for this article.
June 28, 2017: Journal of Antibiotics
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