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Journal of Antibiotics

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https://www.readbyqxmd.com/read/28442735/novel-antibiotic-screening-methods-to-awaken-silent-or-cryptic-secondary-metabolic-pathways-in-actinomycetes
#1
REVIEW
Hiroyasu Onaka
Streptomyces have the potential to produce more than 30 secondary metabolites; however, the expression of most metabolite biosynthetic gene clusters is cryptic or silent. Indeed, the expression of these genes is conditional and dependent on culture conditions. To activate such gene clusters, many methods have been developed. In this review, I describe two activation approaches developed in my laboratory: use of the activation mediator goadsporin and combined-culture. Goadsporin is a chemical substance isolated from Streptomyces sp...
April 26, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28442734/sonochemical-synthesis-of-pyrido-2-3-d-6-5-d-dipyrimidines-catalyzed-by-hnmp-hso4-and-their-antimicrobial-activity-studies
#2
Hossein Naeimi, Asieh Didar, Zahra Rashid, Zohreh Zahraie
In this study, the one-pot four-component reaction of aromatic aldehyde, 2-thiobarbituric acid, ammonium acetate in the presence of a catalytic amount of [H-NMP](+)[HSO4](-) under ultrasonic irradiation in water is reported. In the present procedure, the pyrido[2,3-d:6,5-d']dipyrimidine derivatives were purely produced as valuable products. The process proved to be simple, environmentally friendly, efficient and high to excellent yielding. Moreover, some of the synthetic compounds were investigated and revealed important antimicrobial activity of prepared products...
April 26, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28442733/unique-prostate-cancer-toxic-polyketides-from-marine-sediment-derived-fungus-isaria-felina
#3
Olga F Smetanina, Anton N Yurchenko, Elena V Ivanets, Anatoly I Kalinovsky, Yuliya V Khudyakova, Sergey A Dyshlovoy, Gunhild von Amsberg, Ekaterina A Yurchenko, Shamil Sh Afiyatullov
No abstract text is available yet for this article.
April 26, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28420869/verification-of-oligomycin-a-structure-synthesis-and-biological-evaluation-of-33-dehydrooligomycin-a
#4
Lyudmila N Lysenkova, Oleg Y Saveljev, Natalya E Grammatikova, Vladimir B Tsvetkov, Olga B Bekker, Valery N Danilenko, Lyubov G Dezhenkova, Eugene E Bykov, Olga A Omelchuk, Alexander M Korolev, Andrey E Shchekotikhin
Although, the structure of oligomycin A (1) was confirmed by spectroscopic and chemical evaluations, some crystallographic data cast doubt on the originally adopted structure of the side 2-hydroxypropyl moiety of this antibiotic. It was suggested that the side chain of the oligomycin is enol-related (2-hydroxy-1-propenyl). To clarify this matter we synthesized and evaluated 33-dehydrooligomycin A (2) prepared by the Kornblum oxidation of 33-O-mesyloligomycin A (3) by dimethyl sulfoxide. NMR data for 33-dehydrooligomycin (2) and results of quantum chemical calculations have shown that this derivative exists in the keto rather than in the enol tautomer 2a...
April 19, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28420868/aurachin-ss-a-new-antibiotic-from-streptomyces-sp-na04227
#5
Mei Zhang, Cheng Long Yang, Yong Sheng Xiao, Bo Zhang, Xin Zhao Deng, L I Yang, Jing Shi, Y I Shuang Wang, Wei Li, Rui Hua Jiao, Ren Xiang Tan, Hui Ming Ge
No abstract text is available yet for this article.
April 19, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28400575/heterologous-expression-of-diverse-propionyl-coa-carboxylases-affects-polyketide-production-in-escherichia-coli
#6
Gergana A Vandova, Robert V O'Brien, Brian Lowry, Thomas F Robbins, Curt R Fischer, Ronald W Davis, Chaitan Khosla, Colin Jb Harvey, Maureen E Hillenmeyer
No abstract text is available yet for this article.
April 12, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28377638/biochemical-characterization-of-ctx-m-166-a-new-ctx-m-%C3%AE-lactamase-produced-by-a-commensal-escherichia-coli-isolate
#7
Vera Manageiro, Rafael Graça, Eugénia Ferreira, Lurdes Clemente, Richard Bonnet, Manuela Caniça
No abstract text is available yet for this article.
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28377637/in-vitro-antibacterial-activity-of-mgdg-palmitoyl-from-oscillatoria-acuminata-ntapc05-against-extended-spectrum-%C3%AE-lactamase-producers
#8
Abdul Azees Parveez Ahamed, Mohammed Uddin Rasheed, Kalilurrahuman Peer Muhamed Noorani, Nazar Reehana, Subramanian Santhoshkumar, Yousuff Mohamed Mohamed Imran, Naiyf S Alharbi, Chinnathambi Arunachalam, Sulaiman Ali Alharbi, Mohammad Abdulkader Akbarsha, Nooruddin Thajuddin
Extended-spectrum β-lactamase (ESBL)-producing bacteria pose a big challenge in clinical practices, warranting a new therapeutic strategy. In this study, methanol extract of the marine cyanobacterium Oscillatoria acuminata NTAPC05 was fractionated under bioassay guidance and the fractions were tested against three well-characterized ESBL-producing bacteria Escherichia coli U655, Stenotrophomonas maltophilia B929 and Enterobacter asburiae B938. Out of the four HPLC fractions, fraction 2 showed bactericidal activity against all the three ESBL producers much more efficiently (MIC 100 μg ml(-1)) than the fourth-generation cephalosporin (MIC >125 μg ml(-1))...
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28377636/formal-synthesis-of-thienamycin
#9
Michał Pieczykolan, Bartłomiej Furman, Marek Chmielewski
A formal synthesis of Thienamycin from ethyl (E)-crotonate and a cyclic five-membered nitrone derived from 2-deoxy-d-ribose is described. The synthesis involves 1,3-dipolar cycloaddition, cleavage of the N-O bond in the adduct, and intramolecular N-acylation to afford a bicyclic carbapenam skeleton. Subsequent transformations of the five-membered ring substituents provide the title compound.The Journal of Antibiotics advance online publication, 5 April 2017; doi:10.1038/ja.2017.44.
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28377635/new-diketopiperazine-derivatives-with-cytotoxicity-from-nocardiopsis-sp-yim-m13066
#10
Mingwei Sun, Xiaotong Chen, Wenjun Li, Chunhua Lu, Yuemao Shen
No abstract text is available yet for this article.
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28377634/penicillenols-from-a-deep-sea-fungus-aspergillus-restrictus-inhibit-candida-albicans-biofilm-formation-and-hyphal-growth
#11
Jie Wang, Qi-Feng Yao, Muhammad Amin, Xu-Hua Nong, Xiao-Yong Zhang, Shu-Hua Qi
Penicillenols (A1, A2, B1, B2, C1 and C2) were isolated from Aspergillus restrictus DFFSCS006, and could differentially inhibit biofilm formation and eradicate pre-developed biofilms of Candida albicans. Their structure-bioactivity relationships suggested that the saturation of hydrocarbon chain at C-8, R-configuration of C-5 and trans-configuration of the double bond between C-5 and C-6 of pyrrolidine-2,4-dione unit were important for their anti-biofilm activities. Penicillenols A2 and B1 slowed the hyphal growth and suppressed the transcripts of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4...
April 5, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28352106/bioactive-secondary-metabolites-produced-by-an-endophytic-fungus-gaeumannomyces-sp-js0464-from-a-maritime-halophyte-phragmites-communis
#12
Changyeol Lee, Soonok Kim, Wei Li, Sunghee Bang, Hanna Lee, Hyun-Jung Lee, Eun-Young Noh, Jung-Eun Park, Woo Young Bang, Sang Hee Shim
Endophytes, important plant-associated mycobionts, have attracted a great deal of attention because of their bioactive secondary metabolites. Even though halophytes have been reported to overcome salt stress via associations with their endophytes, few studies have investigated the metabolites produced by the endophytes from halophytes. In this study, a dark septate endophytic fungal strain (JS0464), identified as Gaeumannomyces sp. by ITS sequencing, was isolated from the rhizome of a halophyte, Phragmites communis, in Suncheon bay, South Korea...
March 29, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28352105/conjugative-esbl-plasmids-differ-in-their-potential-to-rescue-susceptible-bacteria-via-horizontal-gene-transfer-in-lethal-antibiotic-concentrations
#13
Sari Mattila, Pilvi Ruotsalainen, Ville Ojala, Timo Tuononen, Teppo Hiltunen, Matti Jalasvuori
No abstract text is available yet for this article.
March 29, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28325930/%C3%AE-ionylidene-type-sesquiterpenoids-possessing-antimicrobial-activity-against-porphyromonas-gingivalis-from-phellinus-linteus-and-their-absolute-structure-determination
#14
Tatsuya Shirahata, Chieko Ino, Fumi Mizuno, Yoshihisa Asada, Masao Hirotani, George A Petersson, Satoshi Ōmura, Takafumi Yoshikawa, Yoshinori Kobayashi
No abstract text is available yet for this article.
March 22, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293039/the-master-regulator-phop-coordinates-phosphate-and-nitrogen-metabolism-respiration-cell-differentiation-and-antibiotic-biosynthesis-comparison-in-streptomyces-coelicolor-and-streptomyces-avermitilis
#15
REVIEW
Juan F Martín, Antonio Rodríguez-García, Paloma Liras
Phosphate limitation is important for production of antibiotics and other secondary metabolites in Streptomyces. Phosphate control is mediated by the two-component system PhoR-PhoP. Following phosphate depletion, PhoP stimulates expression of genes involved in scavenging, transport and mobilization of phosphate, and represses the utilization of nitrogen sources. PhoP reduces expression of genes for aerobic respiration and activates nitrate respiration genes. PhoP activates genes for teichuronic acid formation and reduces expression of genes for phosphate-rich teichoic acid biosynthesis...
March 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293038/naphthacemycins-novel-circumventors-of-%C3%AE-lactam-resistance-in-mrsa-produced-by-streptomyces-sp-kb-3346-5-i-the-taxonomy-of-the-producing-strain-and-the-fermentation-isolation-and-antibacterial-activities
#16
Atsushi Fukumoto, Yong-Pil Kim, Atsuko Matsumoto, Yoko Takahashi, Makoto Suzuki, Hideyuki Onodera, Hiroshi Tomoda, Hidehito Matsui, Hideaki Hanaki, Masato Iwatsuki, Satoshi Ōmura, Kazuro Shiomi
Screening for circumventors of β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) led us to find 17 novel antibiotics, naphthacemycins A1-A11, B1-B4 and C1-C2. The naphthacemycins were isolated from a cultured broth of Streptomyces sp. KB-3346-5 by repeated silica gel column chromatography and HPLC. Naphthacemycins enhanced imipenem activity 100-500 times against MRSA at 0.5 μg ml(-1), and naphthacemycins A4-A11 themselves showed MIC50 values of 1-4 μg ml(-1) against 22 MRSA strains...
March 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293037/structure-and-antibacterial-activities-of-new-cyclic-peptide-antibiotics-pargamicins-b-c-and-d-from-amycolatopsis-sp-ml1-hf4
#17
Hideki Hashizume, Ryuichi Sawa, Kazuma Yamashita, Yoshio Nishimura, Masayuki Igarashi
No abstract text is available yet for this article.
March 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293036/naphthacemycins-novel-circumventors-of-%C3%AE-lactam-resistance-in-mrsa-produced-by-streptomyces-sp-kb-3346-5-ii-structure-elucidation
#18
Atsushi Fukumoto, Yong-Pil Kim, Masato Iwatsuki, Tomoyasu Hirose, Toshiaki Sunazuka, Hideaki Hanaki, Satoshi Ōmura, Kazuro Shiomi
Seventeen new compounds, naphthacemycins A1-A11, B1-B4 and C1-C2, were isolated from a cultured broth of Streptomyces sp. KB-3346-5 during screening for circumventors of β-lactam resistance in methicillin-resistant Staphylococcus aureus. Their structures were elucidated by spectroscopic studies, including NMR and X-ray crystallographic analysis. The naphthacemycin A series has a new skeleton displaying a 7-phenylnaphthacene-5,6,11(12H)-trione. In contrast, the quinone moiety of the A series is changed to dehydroxyquinol in the B series and to a semiquinone-like structure in the C series...
March 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293035/ghanamycins-a-and-b-two-novel-%C3%AE-butyrolactones-from-marine-derived-streptomyces-ghanaensis-txc6-16
#19
Jia-Hui Xu, Kang-Bo Gu, Dao-Jing Zhang, Yuan-Guang Li, Li Tian
Two novel γ-butyrolactones ghanamycins A (1) and B (2) were isolated from the fermentation broth of marine-derived Streptomyces ghanaensis TXC6-16. Their structures were elucidated by spectroscopic analysis. These two novel compounds exhibited antimicrobial activities against some phytopathogens. The minimum IC (MIC) of 2 against Pseudomonas syringae and Erwinia sp. were 50 μg ml(-1).The Journal of Antibiotics advance online publication, 15 March 2017; doi:10.1038/ja.2017.37.
March 15, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28293034/characterization-of-bafilomycin-biosynthesis-in-kitasatospora-setae-km-6054-and-comparative-analysis-of-gene-clusters-in-actinomycetales-microorganisms
#20
Ayako Nara, Takuya Hashimoto, Mamoru Komatsu, Makoto Nishiyama, Tomohisa Kuzuyama, Haruo Ikeda
Bafilomycins A1, C1 and B1 (setamycin) produced by Kitasatospora setae KM-6054 belong to the plecomacrolide family, which exhibit antibacterial, antifungal, antineoplastic and immunosuppressive activities. An analysis of gene clusters from K. setae KM-6054 governing the biosynthesis of bafilomycins revealed that it contains five large open reading frames (ORFs) encoding the multifunctional polypeptides of bafilomycin polyketide synthases (PKSs). These clustered PKS genes, which are responsible for bafilomycin biosynthesis, together encode 11 homologous sets of enzyme activities, each catalyzing a specific round of polyketide chain elongation...
March 15, 2017: Journal of Antibiotics
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