scholarly journals Spin-labeling of Dexamethasone: Radical Stability vs. Temporal Resolution of EPR-Spectroscopy on Biological Samples

2018 ◽  
Vol 232 (5-6) ◽  
pp. 883-891 ◽  
Author(s):  
Karolina A. Walker ◽  
Michael L. Unbehauen ◽  
Silke B. Lohan ◽  
Siavash Saeidpour ◽  
Martina C. Meinke ◽  
...  
Keyword(s):  
Detection Limit ◽  
Hydroxy Group ◽  
Epr Spectroscopy ◽  
Biological Samples ◽  
Spin Labeling ◽  
Hacat Cells ◽  
Nmr Data ◽  
Primary Hydroxy Group ◽  
High Yields ◽  
Stability Measurements

AbstractSpin-labeling active compounds is a convenient way to prepare them for EPR spectroscopy with minimal alteration of the target molecule. In this study we present the labeling reaction of dexamethasone (Dx) with either TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) or PCA (3-(carboxy)-2,2,5,5-tetramethyl-1-pyrrolidinyloxy) with high yields. According to NMR data, both labels are attached at the primary hydroxy group of the steroid. In subsequent spin-stability measurements both compounds were applied onto HaCaT cells. When the signal of Dx-TEMPO decreased below the detection limit within 3 h, the signal of Dx-PCA remained stable for the same period of time.

Direct Etherification of a Single Primary Hydroxy Group of β-Cyclodextrin

2021 ◽  
Vol 57 (1) ◽  
pp. 121-125
Author(s):  
N. V. Kutyasheva ◽  
G. I. Kurochkina ◽  
E. A. Solomatin ◽  
M. K. Grachev
Keyword(s):  
Hydroxy Group ◽  
Primary Hydroxy Group

scholarly journals Bifurcated synthesis of methylene-lactone- and methylene-lactam-fused spirolactams via electrophilic amide allylation of γ-phenylthio-functionalized γ-lactams

2020 ◽  
Vol 16 ◽  
pp. 2769-2775
Author(s):  
Tetsuya Sengoku ◽  
Koki Makino ◽  
Ayumi Iijima ◽  
Toshiyasu Inuzuka ◽  
Hidemi Yoda
Keyword(s):  
Hydroxy Group ◽  
The Other ◽  
Synthetic Methods ◽  
Other Hand ◽  
Acidic Conditions ◽  
High Yields

New synthetic methods for spirolactams bearing an α-methylene-γ-butyrolactone or its analogous methylene-lactam have been developed. The allylation of γ-phenylthio-functionalized γ-lactams with 2-(acetoxy)methyl acrylamides was accomplished by using 2.5 equivalents of NaH to give the corresponding adducts in excellent yields. The remaining phenylthio group was substituted with a hydroxy group by treatment with CuBr, and the resulting γ-hydroxyamides were cyclized under acidic conditions to afford the corresponding methylene-lactam-fused spirolactams in high yields. On the other hand, methylene-lactone-fused spirolactams could be delivered from the allyl adducts in high yields through a sequential N-Boc protection/desulfinative lactonization.

scholarly journals Posttranscriptional site-directed spin labeling of large RNAs with an unnatural base pair system under non-denaturing conditions

2020 ◽  
Vol 11 (35) ◽  
pp. 9655-9664
Author(s):  
Yan Wang ◽  
Venkatesan Kathiresan ◽  
Yaoyi Chen ◽  
Yanping Hu ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Epr Spectroscopy ◽  
Base Pair ◽  
Spin Labeling ◽  
Paramagnetic Resonance ◽  
Site Directed Spin Labeling ◽  
Electron Paramagnetic

Site-directed spin labeling (SDSL) of large RNAs for electron paramagnetic resonance (EPR) spectroscopy has remained challenging to date.

Preparation and Conformational Study of B-Ring Substituted Lupane Derivatives

2006 ◽  
Vol 71 (8) ◽  
pp. 1131-1160 ◽  
Author(s):  
Martin Dračínský ◽  
Simona Hybelbauerová ◽  
Jan Sejbal ◽  
Miloš Buděšínský
Keyword(s):  
Double Bond ◽  
Hydroxy Group ◽  
Molecular Modelling ◽  
Nmr Spectra ◽  
Hydroxy Derivative ◽  
Secondary Hydroxy Group ◽  
Conformational Study ◽  
Primary Hydroxy Group ◽  
Type 3 ◽  
C Nmr

New lupane-type triterpenoids with 5(6) double bond were prepared using the method of partial demethylation on carbon C-4. Hydroboration of the double bond led to 6α-hydroxy derivative. By the oxidation and following reduction of 6α-hydroxy derivative the 6-oxo and 6β-hydroxy derivatives were prepared. A new method for selective oxidation of secondary hydroxy group in the presence of primary hydroxy group was performed. The conformation of ring A of new lupane-type 3-oxo derivatives with a substituent on ring B was elucidated on the bases of 1H and 13C NMR spectra and molecular modelling.

Sensitive analysis of reduced glutathione in bacteria and HaCaT cells by capillary electrophoresis via online pre-concentration of transient trapping combined with the dynamic pH junction mode

2017 ◽  
Vol 41 (21) ◽  
pp. 12920-12929 ◽  
Author(s):  
Yan Zhang ◽  
Wujuan Chen ◽  
Yi Zhang ◽  
Yating Zhang ◽  
Luqi Zhu ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Biological Samples ◽  
Reduced Glutathione ◽  
New Method ◽  
Hacat Cells ◽  
Sensitive Analysis ◽  
Dynamic Ph Junction ◽  
Sensitive Determination

A new method of capillary electrophoresis was developed for the sensitive determination of glutathione in biological samples.

Picomol Assay of Nitric Oxide Screening in Biological Samples by Derivatization Combined with High-Throughput Microplate Format

2013 ◽  
Vol 423-426 ◽  
pp. 1786-1789
Author(s):  
Xiao Ling Zhang ◽  
Qiao Yang
Keyword(s):  
Nitric Oxide ◽  
Detection Limit ◽  
High Throughput ◽  
Biological Samples ◽  
Biological Sample ◽  
Small Volume ◽  
Screening Method ◽  
Broad Variety ◽  
Sensitive Determination

Nitric oxide (NO) is a critical intra-and extra-cellular signaling molecule that mediates a broad variety of physiologic and pathophysiologic events, and has prompted rapid growth of investigations in investigating its physiology and generation mechanism of corresponding diseases. In this paper, a picomol assay of NO screening method using fluorescent derivatization combined with high-throughout microplate format has been developed and successfully applied to the determination of NO in biological samples. The satisfied detection limit and recovery of the proposed method demonstrates that it can be competent for the sensitive determination of NO in extremely small volume of biological sample.

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