scholarly journals Regulusosides A, B, and C, Three New Polyhydroxysteroid Glycosides from the Starfish Pentaceraster regulus

2016 ◽  
Vol 11 (9) ◽  
pp. 1934578X1601100
Author(s):  
Alla A. Kicha ◽  
Natalia V. Ivanchina ◽  
Timofey V. Malyarenko ◽  
Anatoly I. Kalinovsky ◽  
Pavel S. Dmitrenok ◽  
...  
Keyword(s):  
Side Chain ◽  
Raw 264.7 ◽  
Oxygen Species ◽  
Murine Macrophage ◽  
Reactive Oxygen Species Formation ◽  
Species Formation ◽  
Intracellular Ros ◽  
Immunomodulatory Properties ◽  
Chain Compounds ◽  
Ros Reactive Oxygen Species

Three new polyhydroxysteroid glycosides, regulusosides A-C (1-3) along with the previously known five steroid compounds (4-8) were isolated from the tropical starfish Pentaceraster regulus. The structures of compounds 1-3 were established by extensive NMR and ESI-MS techniques. New glycosides have the same aglycon, (24 S)-5α-cholestane-3β,5,6β,8,15α,24-hexol, and various disaccharide moieties: β-D-xylopyranosyl-(1→2)-3- O-methyl-α-L-arabinofuranosyl (1), β-D-xylopyranosyl-(1→2)-α-L-arabinofuranosyl (2), and 2- O-methyl-β-D-xylopyranosyl-(1→2)-3- O-methyl-α-L-arabinofuranosyl (3), attached at C-24 of the side chain. Compounds 1, 2 and 6 exhibit potential immunomodulatory properties, inducing intracellular ROS (reactive oxygen species) formation in the RAW 264.7 murine macrophage cells.

scholarly journals The Influence on LPS-Induced ROS Formation in Macrophages of Capelloside A, a New Steroid Glycoside from the Starfish Ogmaster capella

2015 ◽  
Vol 10 (11) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Natalia V. Ivanchina ◽  
Alla A. Kicha ◽  
Timofey V. Malyarenko ◽  
Anatoly I. Kalinovsky ◽  
Ekaterina S. Menchinskaya ◽  
...  
Keyword(s):  
Ethanolic Extract ◽  
Steroid Glycoside ◽  
Raw 264.7 ◽  
Oxygen Species ◽  
E Coli ◽  
Raw 264.7 Cell ◽  
Intracellular Ros ◽  
Ros Formation ◽  
Raw 264.7 Cell Line ◽  
Ros Reactive Oxygen Species

A new steroid glycoside, capelloside A (1), was isolated from the ethanolic extract of the starfish Ogmaster capella along with the previously known coscinasteroside B (2). The structures of 1 was elucidated by extensive NMR and ESI-MS techniques as (24 S)-24- O-(3- O-methyl-β-D-xylopyranosyl)-5α-cholestane-3β,6β,8,15α,24-pentol 15- O-sulfate (1). Compounds 1 and 2 decreased intracellular ROS (reactive oxygen species) levels in murine macrophages of the RAW 264.7 cell line at induction by endotoxic lipopolysaccharide (LPS) from E. coli by 60% and 41%, correspondingly.

Increased Demethylmenaquinone‐Dependent Reactive Oxygen Species Formation by Β-Lactams in Enterococcus Faecalis

2018 ◽  
Author(s):  
Loïc Léger ◽  
Aurélie Budin-Verneuil ◽  
Margherita Cacaci ◽  
Abdellah Benachour ◽  
Axel Hartke ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Enterococcus Faecalis ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Reactive Oxygen Species Formation ◽  
Species Formation

Carcinogenic metal induced sites of reactive oxygen species formation in hepatocytes

2003 ◽  
Vol 17 (5-6) ◽  
pp. 803-810 ◽  
Author(s):  
Jalal Pourahmad ◽  
Peter J O‘Brien ◽  
Farzaneh Jokar ◽  
Bahram Daraei
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Reactive Oxygen Species Formation ◽  
Species Formation

scholarly journals Type I toxin-dependent generation of superoxide affects the persister life cycle of Escherichia coli

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Daniel Edelmann ◽  
Bork A. Berghoff
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Life Cycle ◽  
Type I ◽  
Oxygen Species ◽  
Reactive Oxygen Species Formation ◽  
Species Formation ◽  
Genes Encoding ◽  
Oxidative Challenge ◽  
Detailed Work

Abstract Induction of growth stasis by bacterial toxins from chromosomal toxin-antitoxin systems is suspected to favor formation of multidrug-tolerant cells, named persisters. Recurrent infections are often attributed to resuscitation and regrowth of persisters upon termination of antibiotic therapy. Several lines of evidence point to oxidative stress as a crucial factor during the persister life cycle. Here, we demonstrate that the membrane-depolarizing type I toxins TisB, DinQ, and HokB have the potential to provoke reactive oxygen species formation in Escherichia coli. More detailed work with TisB revealed that mainly superoxide is formed, leading to activation of the SoxRS regulon. Deletion of the genes encoding the cytoplasmic superoxide dismutases SodA and SodB caused both a decline in TisB-dependent persisters and a delay in persister recovery upon termination of antibiotic treatment. We hypothesize that expression of depolarizing toxins during the persister formation process inflicts an oxidative challenge. The ability to counteract oxidative stress might determine whether cells will survive and how much time they need to recover from dormancy.

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