An endophytic fungus Paraphaeosphaeria neglecta FT462 isolated from the Hawaiian-plant Lycopodiella cernua (L.) Pic. Serm produced one unusual compound (1, paraphaeosphaeride A) with the 4-pyranone-γ-lactam-1,4-thiazine moiety, along with two new compounds (2 and 3, paraphaeosphaerides B and C, respectively) and the known compound (4). Compounds 1-3 were characterized by NMR and MS spectroscopic analysis. The absolute configuration of the 3-position of compound 1 was determined as S by electronic circular dichroism (ECD) calculations. Compound 3 also showed STAT3 inhibition at 10 μM.
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http://dx.doi.org/10.1021/acs.orglett.5b01650 | DOI Listing |
Biochemistry
January 2025
Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
The exterior surface of the human pathogen is coated with a capsular polysaccharide (CPS) that consists of a repeating sequence of 2-5 different sugars that can be modified with various molecular decorations. In the HS:2 serotype from strain NCTC 11168, the repeating unit within the CPS is composed of d-ribose, -acetyl-d-galactosamine, and a d-glucuronic acid that is further amidated with either serinol or ethanolamine. The d-glucuronic acid moiety is also decorated with d-glycero-l-gluco-heptose.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.
is the leading cause of food poisoning in Europe and North America. The exterior surface of this bacterium is encased by a capsular polysaccharide that is attached to a diacyl glycerol phosphate anchor via a poly-Kdo (3-deoxy-d--oct-2-ulosinic acid) linker. In the HS:2 serotype of NCTC 11168, the repeating trisaccharide consists of d-ribose, -acetyl-d-glucosamine, and d-glucuronate.
View Article and Find Full Text PDFChembiochem
January 2025
University of Wisconsin-Madison, Pharmacy, 777 Highland Ave, 53705, Madison, UNITED STATES OF AMERICA.
Peptides and proteins are important functional biomolecules both inside and outside of living organisms. The ability to prepare various types of functionalized peptides and proteins is essential for understanding fundamental biological processes, such as protein folding and post-translational modifications (PTMs), and for developing new therapeutics for many diseases, such as cancers and neurodegenerative diseases. The o-aminoaniline moiety was first proposed for activation to a thioester precursor and used for native chemical ligation to prepare large peptides and proteins.
View Article and Find Full Text PDFACS Infect Dis
January 2025
Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands.
Flagella are essential for motility and pathogenicity in many bacteria. The main component of the flagellar filament, flagellin (FliC), often undergoes post-translational modifications, with glycosylation being a common occurrence. In PAO1, the b-type flagellin is -glycosylated with a structure that includes a deoxyhexose, a phospho-group, and a previous unknown moiety.
View Article and Find Full Text PDFChemistry
January 2025
Université de Rennes 1, Chemistry, Equipe CORINT, Institut des Sciences Chimiques de Rennes, Université de Rennes 1 - UMR 6226 CNRS, Bâtiment 10A, Bureau 158, Avenue du Général Leclerc, 35042, Rennes, FRANCE.
Capozzi's groundbreaking work in 1982 introduced a fascinating reaction involving highly reactive tertiary aliphatic cations and silylated alkynes. This reaction provided an innovative solution to the challenge of coupling a fully substituted tertiary aliphatic fragment with an alkyne moiety. Building upon Capozzi's pioneering efforts, we started an extensive exploration of reaction conditions to expand the initial scope of this reaction.
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