scholarly journals Base-catalyzed Condensation ofo-Nitroacetophenone. V. Hydrogenation of Compound A, a Condensation Product. Formation of a 4-Quinolone from an Indoline System

1972 ◽  
Vol 45 (8) ◽  
pp. 2590-2593 ◽  
Author(s):  
Toshio Miwa
Keyword(s):  
Condensation Product ◽  
Product Formation ◽  
Compound A

Recent development of green protocols towards Knoevenagel condensation: A Review

2021 ◽  
Vol 25 (11) ◽  
pp. 170-174
Author(s):  
Prabal Pratap Singh ◽  
Manmohan Kumar ◽  
Juby K. Ajish
Keyword(s):  
Knoevenagel Condensation ◽  
Condensation Product ◽  
Bond Formation ◽  
Aqueous Media ◽  
Product Formation ◽  
Nano Particles ◽  
Liquid Media ◽  
Green Protocol ◽  
Solvent Free Condition ◽  
Carbon Carbon Bond

A large number of varied synthetic strategies for carbon-carbon bond formation have been proposed by researchers from time to time. Knoevenagel condensation products synthesized by green protocol have been highly appreciated, Knoevenagel products find enormous application in therapeutics and pharmacological. Green synthetic strategies like ionic liquid media, solvent free condition, use of aqueous media and utilization of nano particles towards synthesis of Knoevenagel products have been recently utilized by scientist all over the world. In this study we highlight the recent development of green methods for Knoevengal condensation product formation.

Lignin-Carbohydrate Condensation Product Formation in a Biomimetic Model Pulp Bleaching System

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 385-390 ◽  
Author(s):  
C. C. Walker ◽  
T. J. McDonough ◽  
R. J. Dinus ◽  
K.-E. L. Eriksson
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Condensation Product ◽  
Condensation Reaction ◽  
Product Formation ◽  
Water Soluble ◽  
Hydroxyethyl Cellulose ◽  
Pulp Bleaching ◽  
High Molecular Weight Product ◽  
Molecular Weight Product

Abstract Three biomimetic compounds were evaluated for their ability to preferentially degrade lignin in the presence of carbohydrate using two water-soluble polymeric model compounds: lignosulfonate and hydroxyethyl cellulose (HEC). The three biomimetic systems studied were FeSO4, Fe-EDTA and hemoglobin, each in the presence of hydrogen peroxide. When both polymeric substrates were present, a high molecular weight product was observed to form upon addition of H2O2. This high molecular weight product is believed to be the result of a condensation reaction between lignosulfonate and HEC. The condensation product was also observed to form in the absence of biomimetic catalyst. For all reactions, the molecular weight of the condensation product was observed to decrease with increasing reaction time. By altering the ratio of lignosulfonate to HEC, a limit was observed in the relative amount of condensation product formed. The formation of this condensation product is believed to limit the effectiveness of acidic bleaching systems.

Modulation of glucokinase by glucose, small-molecule activator and glucokinase regulatory protein: steady-state kinetic and cell-based analysis

2012 ◽  
Vol 441 (3) ◽  
pp. 881-887 ◽  
Author(s):  
Francis J. Bourbonais ◽  
Jing Chen ◽  
Cong Huang ◽  
Yanwei Zhang ◽  
Jeffrey A. Pfefferkorn ◽  
...  
Keyword(s):  
Steady State ◽  
Small Molecule ◽  
Regulatory Protein ◽  
Tight Binding ◽  
Rat Hepatocytes ◽  
Product Formation ◽  
Time Dependent ◽  
Imaging Data ◽  
Compound A ◽  
Steady State Kinetic

GK (glucokinase) is an enzyme central to glucose metabolism that displays positive co-operativity to substrate glucose. Small-molecule GKAs (GK activators) modulate GK catalytic activity and glucose affinity and are currently being pursued as a treatment for Type 2 diabetes. GK progress curves monitoring product formation are linear up to 1 mM glucose, but biphasic at 5 mM, with the transition from the lower initial velocity to the higher steady-state velocity being described by the rate constant kact. In the presence of a liver-specific GKA (compound A), progress curves at 1 mM glucose are similar to those at 5 mM, reflecting activation of GK by compound A. We show that GKRP (GK regulatory protein) is a slow tight-binding inhibitor of GK. Analysis of progress curves indicate that this inhibition is time dependent, with apparent initial and final Ki values being 113 and 12.8 nM respectively. When GK is pre-incubated with glucose and compound A, the inhibition observed by GKRP is time dependent, but independent of GKRP concentration, reflecting the GKA-controlled transition between closed and open GK conformations. These data are supported by cell-based imaging data from primary rat hepatocytes. This work characterizes the modulation of GK by a novel GKA that may enable the design of new and improved GKAs.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

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