scholarly journals Understanding phenolic acids inhibition of α-amylase and α-glucosidase and influence of reaction conditions

2022 ◽  
Vol 372 ◽  
pp. 131231
Author(s):  
Andrea Aleixandre ◽  
José Vicente Gil ◽  
Jorge Sineiro ◽  
Cristina M. Rosell
Keyword(s):  
Phenolic Acids ◽  
Reaction Conditions

Undecagold labeling of tRNA

1991 ◽  
Vol 49 ◽  
pp. 44-45
Author(s):  
James F. Hainfeld ◽  
Kyra M. Alford ◽  
Mathias Sprinzl ◽  
Valsan Mandiyan ◽  
Santa J. Tumminia ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Electron Micrograph ◽  
Anticodon Loop ◽  
Electron Micrograph ◽  
Reaction Conditions ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The undecagold (Au11) cluster was used to covalently label tRNA molecules at two specific ribonucleotides, one at position 75, and one at position 32 near the anticodon loop. Two different Au11 derivatives were used, one with a monomaleimide and one with a monoiodacetamide to effect efficient reactions.The first tRNA labeled was yeast tRNAphe which had a 2-thiocytidine (s2C) enzymatically introduced at position 75. This was found to react with the iodoacetamide-Aun derivative (Fig. 1) but not the maleimide-Aun (Fig. 2). Reaction conditions were 37° for 16 hours. Addition of dimethylformamide (DMF) up to 70% made no improvement in the labeling yield. A high resolution scanning transmission electron micrograph (STEM) taken using the darkfield elastically scattered electrons is shown in Fig. 3.

Screening of sage and thyme plant extracts for some phenolic acids and rutin

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
S Huseinovic ◽  
M Salihovic ◽  
A Topcagic ◽  
K Kalcher ◽  
S Cavar ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Plant Extracts

Content of some phenolic acids and rutin in the leaves and roots of Symphytum officinale L.

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
I Tahirovic ◽  
Z Rimpapa ◽  
S Cavar ◽  
S Huseinovic ◽  
S Muradic ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Symphytum Officinale ◽  
Leaves And Roots

Phenolic acids and C-glycoside flavonoids in Merostachys riedeliana (bamboo)

Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
L Torres ◽  
C José ◽  
R Shirasuna ◽  
MT Grombone-Guaratini
Keyword(s):  
Phenolic Acids

Inhibition by Phenol and Phenolic Acids of Platelet Release Reaction

1973 ◽  
Vol 30 (02) ◽  
pp. 334-338 ◽  
Author(s):  
Felisa C. Molinas
Keyword(s):  
Renal Failure ◽  
Phenolic Compounds ◽  
Phenolic Acids ◽  
Platelet Function ◽  
Deleterious Effect ◽  
Release Reaction ◽  
Contributory Factors ◽  
Adp Release ◽  
Platelet Release

SummaryIt has been postulated that the high phenol and phenolic acids plasmatic levels found in patients with chronic renal failure are contributory factors in the abnormal platelet function described in these patients. This hypothesis was corroborated by “in vitro” studies showing the deleterious effect of these compounds on certain platelet function after pre-incubation of PRP with phenol and phenolic compounds. The present studies were conducted to determine the influence of phenolic compounds on platelet release reaction. It was found that phenol inhibited from 62.5 to 100% the effect of the aggregating agents thrombin, adrenaline and ADP on platelet 5-HT-14C release. The phenolic acids p-, m-, and o-HPAA inhibited from 36.35 to 94.8% adrenaline and ADP-induced platelet 5-HT-14C release. Adrenaline-induced platelet ADP release was inhibited from 27.45 to 38.10% by the phenolic compounds. These findings confirm the hypothesis that phenolic compounds interfere with platelet function through the inhibition of the release reaction.

Dimensionally-Controlled Hydrothermal Tm3+-doped Oxidic Nanocrystals and Their Photoluminescence Properties

2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales
Keyword(s):  
Single Crystals ◽  
Fluorescence Lifetimes ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
Hydrothermal Processes ◽  
Bulk Single Crystals ◽  
Template Free ◽  
Reaction Media

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

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