Steroid derivatives V, VI, VII and VIII reacted with Lawesson's reagent (LR) to produce spiro-oxazaphosphole-4',17-androstene derivative XI, diazaphospholoandrostane XIV and the thionated derivatives XVI and XVII, respectively. The structures of the new compounds were confirmed by analytical and spectroscopic evidence. A mechanism accounting for the formation of the new compounds was given. The in vitro antimicrobial activity of the new compounds were tested.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.steroids.2004.11.001 | DOI Listing |
J Chem Ecol
January 2025
Department of Nematology, University of California Riverside, Riverside, CA, USA.
Plants produce defensive toxins to deter herbivores. In response, some specialized herbivores evolved resistance and even the capacity to sequester toxins, affecting interactions at higher trophic levels. Here, we test the hypothesis that potential natural enemies of specialized herbivores are differentially affected by plant toxins depending on their level of adaptation to the plant-herbivore system.
View Article and Find Full Text PDFInt J Chron Obstruct Pulmon Dis
January 2025
Department of Emergency Medicine, West China Hospital, Sichuan University, Chengdu, People's Republic of China.
Background: This study aims to investigate the association between vitamin D levels and the risk of severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD).
Methods: We conducted a prospective observational study with 636 COPD patients admitted for exacerbations between January 2021 and December 2022. Patients were categorized based on serum 25-hydroxyvitamin D levels: severe deficiency (<10 ng/mL), deficiency (10-20 ng/mL), insufficiency (20-30 ng/mL), or sufficiency (>30 ng/mL).
Front Immunol
January 2025
IrsiCaixa, Badalona, Spain.
Introduction: HIV-1 exploits dendritic cells (DCs) to spread throughout the body via specific recognition of gangliosides present on the viral envelope by the CD169/Siglec-1 membrane receptor. This interaction triggers the internalization of HIV-1 within a structure known as the sac-like compartment. While the mechanism underlying sac-like compartment formation remains elusive, prior research indicates that the process is clathrin-independent and cell membrane cholesterol-dependent and involves transient disruption of cortical actin.
View Article and Find Full Text PDFNon-islet cell tumor hypoglycemia (NICTH) is a paraneoplastic syndrome associated with non-mesenchymal-derived and epithelial tumors. A 37-year-old male with stage IVB hepatocellular carcinoma (HCC) and pulmonary metastases presented with recurrent hypoglycemia despite glucose supplementation. Laboratory findings revealed low insulin growth factor 1 (IGF-1) (15 ng/mL), elevated insulin growth factor 2 (IGF-2) (395 ng/ml), and an IGF-2:IGF-1 ratio of 26:1, consistent with NICTH.
View Article and Find Full Text PDFTalanta
January 2025
Center for Multiplatform Metabolomics Studies (CEMM) at the Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, 05508-000, Brazil. Electronic address:
There is no consensus in the literature regarding the ideal protocol for obtaining and preparing cell samples for untargeted metabolomics. Nevertheless, the procedures must be carefully evaluated for proper and reliable results for each organism under study. This work proposes a novel protocol for determining intracellular metabolites in Leishmania promastigotes and is fully optimized for application in conjunction with gas chromatography-mass spectrometry platforms.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!