Roimatacene (1) was isolated from the myxobacterium Cystobacter ferrugineus strain Cb G35 in a bioactivity-guided process, by following the antimicrobial activity against Escherichia coli. Since 1 was extremely sensitive to oxygen, a protective isolation and handling protocol was developed, by utilizing the free radical scavenger 4-ethoxyphenol. The structure of 1 was determined by HRMS, 1D and 2D NMR spectroscopy and chemical derivatization to acetonides and Mosher esters to finally establish the absolute configuration. Methionine and acetate were identified as building blocks in the biosynthesis of 1 by feeding experiments with differently (13)C-labeled precursors. The antimicrobial activity of 1 was determined in a broad screening revealing 1 to inhibit several Gram-negative bacteria.
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http://dx.doi.org/10.1002/chem.201003677 | DOI Listing |
Microb Biotechnol
January 2025
Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
Glucose is the most abundant monosaccharide and a principal substrate in biotechnological production processes. In Pseudomonas, this sugar is either imported directly into the cytosol or first oxidised to gluconate in the periplasm. While gluconate is taken up via a proton-driven symporter, the import of glucose is mediated by an ABC-type transporter, and hence both require energy.
View Article and Find Full Text PDFEur J Pediatr
January 2025
Department of Pediatrics, Ganzhou People's Hospital, No. 16 Meiguan Avenue, Zhanggong District, Ganzhou, 341000, Jiangxi Province, China.
Unlabelled: This research aimed to describe the effect of azithromycin combined with fluticasone propionate aerosol inhalation on immune function in children with chronic cough caused by Mycoplasma pneumoniae (MP) infection. This study was a retrospective analysis in which 110 children with chronic cough caused by MP infection were divided into two groups based on different treatment methods: 58 cases in the control group treated with azithromycin dry suspension and 52 cases in the intervention group treated with azithromycin dry suspension and fluticasone propionate inhalation aerosol. Lung function, inflammatory factors, immune indicators, laboratory-related indicators, adverse reactions, and therapeutic effects were compared between the two groups.
View Article and Find Full Text PDFPhotosynth Res
January 2025
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia, 119991.
The femtosecond dynamics of energy transfer from light-excited spirilloxanthin (Spx) to bacteriochlorophyll (BChl) a in the reaction centers (RCs) of purple photosynthetic bacteria Rhodospirillum rubrum was studied. According to crio-electron microscopy data, Spx is located near accessory BChl a in the B-branch of cofactors. Spx was excited by 25 fs laser pulses at 490 nm, and difference absorption spectra were recorded in the range 500-700 nm.
View Article and Find Full Text PDFSci Rep
January 2025
School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
The magnetization strategy of isoquinoline alkaloids has been successfully used in the extraction and isolation, but the effect of the magnetization on biological activities of those alkaloids still deserves further investigation. Therefore, the antibacterial, lipid-lowering and antioxidant activities of five isoquinoline alkaloids (berberine, tetrahydroberberine, palmatine, tetrahydropalmatine and tetrahydropapavine) before and after magnetization were compared in this study, and the results showed that the relevant activities were enhanced after magnetization. Additionally, among the five magnetic derivatives studied, berberine magnetic derivative ([Ber·H][FeCl]) had the best antibacterial effect on S.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medical & Health Sciences Tel Aviv University, Tel Aviv, Israel.
Antibiotic resistance is influenced by prior antibiotic use, but precise causal estimates are limited. This study uses penicillin allergy as an instrumental variable (IV) to estimate the causal effect of antibiotics on resistance. A retrospective cohort of 36,351 individuals with E.
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