Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of an alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes differing in alkaloid profiles were sequenced, revealing that those with mutated lolO accumulated exo-1-acetamidopyrrolizidine but no lolines. Heterologous expression of wild-type lolO complemented a lolO mutant, resulting in the production of N-acetylnorloline. These results indicated that the non-heme iron oxygenase, LolO, is required for ether bridge formation, probably through oxidation of exo-1-acetamidopyrrolizidine.
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http://dx.doi.org/10.1016/j.phytochem.2013.11.015 | DOI Listing |
J Biomed Mater Res A
January 2025
Discipline of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, Dublin 2, Ireland.
With no effective treatments for functional recovery after injury, spinal cord injury (SCI) remains one of the unresolved healthcare challenges. Human induced pluripotent stem cell (hiPSC) transplantation is a versatile patient-specific regenerative approach for functional recovery after SCI. Injectable electroconductive hydrogel (ECH) can further enhance the cell transplantation efficacy through a minimally invasive manner as well as recapitulate the native bioelectrical microenvironment of neural tissue.
View Article and Find Full Text PDFACS Bio Med Chem Au
December 2024
Department of Chemistry, The University of Hong Kong, 999077 Hong Kong Special Administrative Region, Hong Kong, China.
Macrocyclization is a vital process in the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), significantly enhancing their structural diversity and biological activity. Universally found in living organisms, cytochrome P450 enzymes (P450s) are versatile catalysts that facilitate a wide array of chemical transformations and have recently been discovered to contribute to the expansion and complexity of the chemical spectrum of RiPPs. Particularly, P450-catalyzed biaryl-bridged RiPPs, characterized by highly modified structures, represent an intriguing but underexplored class of natural products, as demonstrated by the recent discovery of tryptorubin A, biarylitide and cittilin.
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December 2024
Division of Pediatric Surgery, Department of Surgery, Max Rady College of Medicine, University of Manitoba, and Children's Hospital Research Institute of Manitoba, AE402-820 Sherbrook Street, Winnipeg, MB, R3A 1S1, Canada.
Purpose: Circular RNAs (circRNAs) are stable, non-coding RNAs with tissue- and developmental-specific expression making them suitable biomarkers for congenital anomalies. Current circRNA discovery pipelines have focused on human and mouse. We aim to bridge this gap by combining bioinformatics resources and used circtial1 as a model candidate in the nitrofen rat model of congenital diaphragmatic hernia (CDH).
View Article and Find Full Text PDFScand J Trauma Resusc Emerg Med
December 2024
Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Background: Pain therapy is an important first-response measure in the pre-clinical care of trauma patients. Injured individuals on ski slopes are usually given first aid by members of the ski patrol. The early implementation of adequate pain therapy by these paramedical rescuers can increase patient satisfaction and have a positive effect on the entire treatment process.
View Article and Find Full Text PDFJ Inflamm Res
December 2024
Central Laboratory of The Lishui Hospital of Wenzhou Medical University, The First Affiliated Hospital of Lishui University, Lishui People's Hospital, Lishui, Zhejiang, 323000, People's Republic of China.
Background: Throughout history, plants have played a crucial role in advancing medicinal treatments by providing a diverse range of compounds for the development of innovative therapies. L. a tropical herb of the Cannaceae family, also known as Indian shot, has a rich history of traditional use in treating ailments like inflammation, malaria, dysentery, fever, dropsy, and diarrhea.
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