Read by QxMD icon Read

Journal of Antibiotics

Feng-Xian Yang, Guan-Xiong Hou, Jianying Luo, Jing Yang, Yijun Yan, Sheng-Xiong Huang
Chemical investigation of a strain Streptomyces sp. KIB-H1318 isolated from soil sample led to the discovery of three new phenoxazinone-related alkaloids 1-3, as well as two known analogs exfoliazone (4) and viridobrunnine A (5). Their structures were determined on the basis of extensive spectroscopic analysis. The antimicrobial activity and cytotoxicity of the isolates were assayed. Exfoliazone and viridobrunnine A exhibited minor antibacterial activity against Escherichia coli ATCC 8099, Bacillus subtilis ATCC 6633, and Staphylococcus aureus ATCC 6538...
September 14, 2018: Journal of Antibiotics
Sajith Raghunandanan, Leny Jose, Ramakrishnan Ajay Kumar
Isoniazid (INH) is one among the four first-line drugs used in the treatment of tuberculosis. The bactericidal activity of INH is due to its ability to inhibit mycolic acid synthesis, which is an integral component of the mycobacterial cell wall. Non-replicating Mycobacterium tuberculosis (MTB) is phenotypically resistant to INH. The exact mechanism of this resistance is not clear, although the inability of dormant MTB to convert the pro-drug into an active form is thought to be one of the possible reasons...
September 5, 2018: Journal of Antibiotics
Nourhan Hisham Shady, Mostafa A Fouad, Safwat Ahmed, Sheila Marie Pimentel-Elardo, Justin R Nodwell, Mohamed Salah Kamel, Usama Ramadan Abdelmohsen
The antitrypanosomally active crude extract of the sponge Hyrtios sp. was subjected to metabolomic analysis using liquid chromatography coupled with high resolution electrospray ionization mass spectrometry (LC-HR-ESIMS) for dereplication purposes. As a result, a new alkaloid, hyrtiodoline A (1), along with other four known compounds (2-5) were reported. The structures of compounds 1-5 were determined by spectroscopic analyses, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESI-MS) experiments, as well as comparison to the literature...
September 4, 2018: Journal of Antibiotics
Taichi Ohshiro, Reiko Seki, Takashi Fukuda, Ryuji Uchida, Hiroshi Tomoda
New indanones, designated celludinones A ((±)-1) and B (2), were isolated from the culture broth of the fungal strain Talaromyces cellulolyticus BF-0307. The structures of celludinones were elucidated by spectroscopic data, including 1D and 2D NMR. Celludinone A was found to be a mixture of racemic isomers ((±)-1), which were isolated by a chiral column. Compounds (+)-1 and (-)-1 inhibited the sterol O-acyltransferase (SOAT) 1 and 2 isozymes in a cell-based assay using SOAT1- and SOAT2-expressing Chinese hamster ovary (CHO) cells, while 2 selectively inhibited the SOAT2 isozyme...
September 3, 2018: Journal of Antibiotics
Jie Bao, Fei He, Yumei Li, Lei Fang, Kaiming Wang, Jintong Song, Jie Zhou, Qiang Li, Hua Zhang
Three new angucycline-type C-glycosides, grincamycins L-N (1-3), together with the known rabelomycin (4), moromycin B (5), fridamycin D (6), saquayamycin B1 (7), actinomycin X2 (8), and actinomycin D (9), were isolated from the culture of the soil-derived Streptomyces sp. XZHG99T collected from Color desert, Dengpa District, Tibet. The structures of 1-3 were established by detailed analyses of comprehensive spectroscopic data. Compounds 1-9 exhibited significant cytotoxicity against a panel of human cancer cell lines A549, H157, MCF7, MDA-MB-231, and HepG2, while 4, 8, and 9 showed decent antibacterial activity against Mycobacterium smegmatis and Staphylococcus aureus...
August 29, 2018: Journal of Antibiotics
Bingya Jiang, Wei Zhao, Shufen Li, Hongyu Liu, Liyan Yu, Weixiao Niu, Hongwei He, Linzhuan Wu
A quinoxalinone-bohemamine hybrid compound quinohemanine (1), together with 1-methyl-2(H)-quinoxalin-2-one (2), was isolated from Streptomyces sp. CPCC 200497, a producer of quinomycins and bohemamines. Compounds 1 and 2 were purified using standard chromatographic methods, and their structures were defined through interpretation of HRMS, 1D, and 2D NMR data. Both 1 and 2 displayed moderate cytotoxicity against cancer cell line HepG2.
August 29, 2018: Journal of Antibiotics
Kazuki Ujiie, Hideyuki Matsuura, Tran Thi My Duyen, Koki Izutsu, Ayaka Nitta, Kazuo Harada, Kazumasa Hirata
Sulfonamide residue in foodstuffs and the environment is a serious global concern for their contribution to the occurrence of antibiotic-resistant bacteria, especially in developing countries. Here, we describe a novel, simple, and low-cost bioassay for sulfonamides, which has high potential versatility for use in low-resource settings. The bioassay method is based on a purpose-built luminescent assay reaction that detects sulfonamide groups. The luminescent assay reaction comprises dihydropteroate synthase, a target enzyme of sulfonamides, and luminescent pyrophosphate detection reagent, which triggers a sequence of biomolecular reactions that convert sulfonamides to emit luminescence...
August 23, 2018: Journal of Antibiotics
Jueun Kim, Pyoung Il Kim, Ki Moon Bong, Jae Il Kim, Song Yub Shin, Jaekyeong Song, Hye Jung Min, Chul Won Lee
Pelgipeptins are cyclic lipopeptides composed of nine amino acids and a short fatty acid chain. In the present study, we report a novel pelgipeptin peptide that was isolated from Paenibacillus elgii BC34-6 and named pelgipeptin E (PGP-E). The molecular mass of PGP-E was 1072 Da as determined by liquid chromatography-mass spectrometry and the amino acid sequence was elucidated by tandem mass spectrometry. The complete molecular structure of PGP-E was characterized using 2D NMR spectroscopy. PGP-E consisted of a cyclic peptide backbone of Dab1-Val2-Dab3-Phe4-Leu5-Dab6-Val7-Leu8-Ser9 and a lipid chain (-CH2 CH2 CH3 )...
August 22, 2018: Journal of Antibiotics
Mitsuyo Horikawa, Mitsuaki Shimazu, Maki Aibe, Hiroto Kaku, Makoto Inai, Tetsuto Tsunoda
Four red polyketide pigments, uroleuconaphins A1 (1) and B1 (2) and their glucosides 3 and 4, were isolated from the red goldenrod aphid Uroleucon nigrotuberculatum. Although these red pigments exist only as glucosides 3 and 4 in the intact insect body, 3 and 4 convert instantly to aglycones 1 and 2 at death. Pigments 1 and 2 inhibited the growth of Lecanicillium sp. (Ascomycota: Cordycipitaceae) and 1, 2, and 3 were active against Conidiobolus obscurus (Entomophthoromycota; Entomophthorales); these fungal species are pathogenic...
August 20, 2018: Journal of Antibiotics
Zhikun Zhang, Xinzhuo Zhang, Luhua Zhang, Guangxi Wang, Jing Zeng, Jinping Zhang, Xiaoyan Hu, Yingshun Zhou
Streptococcus pneumoniae is a pathogen that mainly affects children and elderly individuals. The numerous serotypes and increased resistance to antibiotics make the treatment of pneumococcal infections sometimes difficult. Asymptomatic colonization is the main reservoir for S. pneumoniae, but no vaccine or antibiotic treatment is effective in eliminating this reservoir. Here, we show that a simulated choline binding polypeptide (ChBp) of LytA has antimicrobial activity against S. pneumoniae. ChBp showed specific antimicrobial activity against pneumococcal but not against non-streptococcal strains, and no cytotoxic effect was observed for 293t cell...
August 20, 2018: Journal of Antibiotics
Ryota Hagihara, Yohei Katsuyama, Yoshinori Sugai, Hiroyasu Onaka, Yasuo Ohnishi
Recently, a novel nitrous acid biosynthetic pathway composed of two enzymes was discovered to be involved in the biosynthesis of cremeomycin for the formation of its diazo group. In this pathway, CreE oxidizes L-aspartic acid to nitrosuccinic acid and CreD liberates nitrous acid from nitrosuccinic acid. Bioinformatic analysis showed that various actinobacteria have putative secondary metabolite biosynthesis gene clusters containing creE and creD homologs, suggesting that this pathway is widely used for the biosynthesis of various natural products...
August 17, 2018: Journal of Antibiotics
James F Shurko, Ralph S Galega, Chuxi Li, Grace C Lee
Treatment of Staphylococcus aureus infections continues to be a challenge due to antimicrobial resistance. Endogenous antimicrobial peptides may offer a new option for treating S. aureus infections but several factors limit their clinical utility. Herein, we studied the activity of the antimicrobial peptide LL-37 and two truncated derivatives, LL-13 and LL-17 alone and in combination with vancomycin against a range of drug-resistant S. aureus strains including methicillin resistant S. aureus (MRSA) and vancomycin resistant S...
August 17, 2018: Journal of Antibiotics
Jong-Shik Kim, In-Kyoung Lee, Bong-Sik Yun
Yeast biosurfactants have potent applications in medical, cosmeceutical, and food industries due to their specific modes of action, low toxicity, and applicability. In this study, biosurfactant-producing yeasts were screened for various industrial applications. Among them, Aureobasidium pullulans strain A11211-4-57 with potent surfactant activity from fleabane flower, Erigeron annus (L.) pers., was selected. From culture supernatant of strain A11211-4-57, five new low-surface-tension chemicals designated as pullusurfactans A-E were identified through consecutive chromatography steps, involving ODS, silica gel, Sephadex LH-20, and ODS Sep-pak cartridge columns...
August 15, 2018: Journal of Antibiotics
Yoichi Hayakawa, Taishin Kuriyama, Yuta Ibusuki, Shoko Kimata
A neuroprotective compound designated pyroxazone (1) was isolated from the culture broth of Streptomyces sp. RAN54. The molecular formula of 1 was established as C18 H14 N2 O5 by high-resolution FAB-MS. The structure was determined to be a new 2-amino-3H-phenoxazin-3-one derivative by NMR spectroscopic analysis. Pyroxazone (1) protected C6 rat glioma cells and N18-RE-105 rat primary retina-mouse neuroblastoma hybrid cells from glutamate-induced toxicity with EC50 s of 8.2 µM and 1.7 µM, respectively.
August 15, 2018: Journal of Antibiotics
Chen Wang, Ping Wu, Lei Yao, Jinghua Xue, Liangxiong Xu, Hanxiang Li, Wangqiu Deng, Xiaoyi Wei
Four new peptaibiotics, acremotins A-D (1-4) featuring three α,α-dialkylated amino acid-imino acid motifs and an unreduced C-terminal residue, along with the known peptaibiotic XR586 (5) were isolated from the solid cultures of the soil-derived fungus Acremonium persicinum SC0105. Their primary structures were characterized by detailed analysis of the HRESIMS/MS fragmentation pattern combined with comprehensive interpretation of the 1D and 2D NMR spectroscopic data. The absolute configurations of amino acid residues were determined by the advanced Marfey's method...
August 8, 2018: Journal of Antibiotics
Yohei Shimizu, Yasushi Ogasawara, Atsuko Matsumoto, Tohru Dairi
We searched for specific inhibitors of the futalosine pathway, non-canonical pathway of menaquinone biosynthesis operating in Helicobacter pylori, from metabolites produced by actinomycetes. Aplasmomycin, a boron-containing macrodiolide, was isolated from Streptomyces sp. K15-0223 as a specific inhibitor of the futalosine pathway. We also showed boromycin, an analog of aplasmomycin, had similar activity.
August 8, 2018: Journal of Antibiotics
Shiying Zhang, Jing Fu, Belgin Dogan, Ellen J Scherl, Kenneth W Simpson
5-aminosalicylate (5-ASA) is widely prescribed for the treatment of inflammatory bowel disease (IBD) and prevention of inflammation-associated colorectal cancer (CRC). Its clinical effect is widely attributed to modulation of host inflammatory responses. However, the recent association of intestinal dysbiosis and selective enrichment in Escherichia coli in patients with IBD and CRC raises the possibility that 5-ASA might also affect the enteric microflora. The aim of this study was to investigate the effect of 5-ASA on the growth and virulence of E...
July 26, 2018: Journal of Antibiotics
Binglin Zhang, Shukun Tang, Ximing Chen, Gaoseng Zhang, Wei Zhang, Tuo Chen, Guangxiu Liu, Shiweng Li, Luciana Terra Dos Santos, Helena Carla Castro, Paul Facey, Matthew Hitchings, Paul Dyson
A novel actinobacterial strain, designated S10T , was isolated from a sand sample collected from the Qaidam Basin in Qinghai province, China. The strain S10T exhibited antibacterial activity against MRSA. The taxonomic position of the strain S10T was determined by a polyphasic approach. There were six copies of 16S rDNA in S10T which were not same exactly (MH257693-MH257698). Phylogenetic analysis of 16S rRNA gene sequences indicated the strain belonging to the genus Streptomyces and it showed high sequence similarities with Streptomyces chartreusis NBRC 12753T (99...
July 19, 2018: Journal of Antibiotics
Yoichi Hayakawa, Risako Sone, Haruna Aoki, Shoko Kimata
Two new cytotoxic antibiotics designated quinomycins H1 (2) and H2 (3) were isolated from the culture broth of Streptomyces sp. RAL404. The molecular formula of both compounds was established as C52 H65 N11 O13 S2 by electrospray ionization mass spectrometry (ESI-MS). Their structures were determined as echinomycin (1) derivatives containing a 3-hydoxyquinaldic acid molecule in place of one of the two quinoxaline-2-carboxylic acid chromophores. Quinomycins H1 (2) and H2 (3) showed selective cytotoxicity against RG-E1-4 cells bearing the adenovirus oncogenes with IC50 s of 11 nM and 12 nM, respectively...
July 17, 2018: Journal of Antibiotics
Daniela Rebollar-Ramos, Martha L Macías-Ruvalcaba, Mario Figueroa, Huzefa A Raja, Martín González-Andrade, Rachel Mata
From the rice-based culture of Malbranchea flavorosea, three new compounds namely flavoroseoside B (5-desoxy-5-chloro-flavoroseoside) (2), 4-hydroxy-2-O-α-ribofuranosyl-5-methylacetophenone (3), and (S)-3,4-dihydro-3-(1H-indol-3-ylmethyl)-4-methyl-1H-1,4-benzodiazepine-2,5-dione (4), along with three known compounds, rosigenin (5), massarilactone B (6), and riboxylarinol B (7) were obtained. The structures were determined by spectroscopic methods. Compound 4 and its synthetic analog 3,4-dihydro-3-(1H-indol-3-ylmethyl)-1-methyl-1H-1,4-benzodiazepine-2,5-dione (9) inhibited the activity of Ruminococus obeum α-glucosidase enzyme...
July 17, 2018: Journal of Antibiotics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"