Medermycin, produced by Streptomyces species, represents a family of antibiotics with significant activity against Gram-positive pathogens. The biosynthesis of this family of natural products has been studied, and new skeletons related to medermycin have rarely been reported until recently. Herein, we report eight chimeric medermycin-type natural products with unusual polycyclic skeletons. The formation of these compounds features some key nonenzymatic steps, which inspired us to construct complex polycyclic skeletons via three efficient one-step reactions under mild conditions. This strategy was further developed to efficiently synthesize analogues for biological activity studies. The synthetic compounds, chimedermycins L and M, and sekgranaticin B, show potent antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and methicillin-resistant Staphylococcus epidermidis. This work paves the way for understanding the nonenzymatic formation of complex natural products and using it to synthesize natural product derivatives.
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http://dx.doi.org/10.1038/s41467-022-32901-0 | DOI Listing |
Database (Oxford)
January 2025
Department of In Vitro Toxicology and Dermato-Cosmetology (IVTD), Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels 1090, Belgium.
The European Union's ban on animal testing for cosmetic products and their ingredients, combined with the lack of validated animal-free methods, poses challenges in evaluating their potential repeated-dose organ toxicity. To address this, innovative strategies like Next-Generation Risk Assessment (NGRA) are being explored, integrating historical animal data with new mechanistic insights from non-animal New Approach Methodologies (NAMs). This paper introduces the TOXIN knowledge graph (TOXIN KG), a tool designed to retrieve toxicological information on cosmetic ingredients, with a focus on liver-related data.
View Article and Find Full Text PDFCien Saude Colet
January 2025
Departamento de Medicina Preventiva, Faculdade de Medicina, Universidade de São Paulo. São Paulo SP Brasil.
Progressive declines in vaccination coverage have been recorded in Brazil in recent years. The COVID-19 pandemic has introduced even more challenges to this scenario. Considering the pandemic as an event, the scope of this article was to analyze the politicization of vaccines from the perspective of caregivers of young children.
View Article and Find Full Text PDFSci Transl Med
January 2025
Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
At this stage in the COVID-19 pandemic, most infections are "breakthrough" infections that occur in individuals with prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure. To refine long-term vaccine strategies against emerging variants, we examined both innate and adaptive immunity in breakthrough infections. We performed single-cell transcriptomic, proteomic, and functional profiling of primary and breakthrough infections to compare immune responses from unvaccinated and vaccinated individuals during the SARS-CoV-2 Delta wave.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses lead to severe respiratory illnesses and death in humans, exacerbated in individuals with underlying health conditions, remaining substantial global public health concerns. Here, we developed a bivalent replication-incompetent single-cycle pseudotyped vesicular stomatitis virus vaccine that incorporates both a prefusion-stabilized SARS-CoV-2 spike protein lacking a furin cleavage site and a full-length influenza A virus neuraminidase protein. Vaccination of K18-hACE2 or C57BL/6J mouse models generated durable levels of neutralizing antibodies, T cell responses, and protection from morbidity and mortality upon challenge with either virus.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Dyes and Chemical Engineering, Bangladesh University of Textiles, Dhaka, Bangladesh.
Tinospora cordifolia extract exhibits diverse benefits-anti-arthritis, anti-malarial, anti-allergic, anti-diabetic, antihepatotoxic, and antipyretic effects. Its specific anti-inflammatory and healing capacities remain unexplored, prompting a study utilizing a mouse skin wound model and direct T. cordifolia extraction.
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