scholarly journals Reactivity of isocoumarins. I. Effect of a neighboring hydroxyl group on the reduction of the lactone carbonyl group.

1980 ◽  
Vol 28 (3) ◽  
pp. 723-729 ◽  
Author(s):  
MASATOSHI YAMATO ◽  
TADATAKA ISHIKAWA ◽  
TOMOHISA NAGAMATSU ◽  
SHIN YOSHIKAWA ◽  
TAKAJI KOYAMA
Keyword(s):  
Carbonyl Group ◽  
Hydroxyl Group ◽  
Lactone Carbonyl

Physical Stability and Lyophilization of Poly(ε-caprolactone)-b-Poly(ethyleneglycol)-b-Poly(ε-caprolactone) Micelles

2006 ◽  
Vol 6 (9) ◽  
pp. 3032-3039 ◽  
Author(s):  
Yong Hu ◽  
Yin Ding ◽  
Yuan Li ◽  
Xiqun Jiang ◽  
Changzheng Yang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Fluorescence Spectra ◽  
Physical Stability ◽  
Storage Period ◽  
Aqueous Dispersion ◽  
Hydroxyl Group ◽  
Core Shell ◽  
Ft Ir ◽  
The Stability

The stability and lyophilization of core–shell PCL-PEG-PCL micelles were investigated by fluorescence spectra, DLS, DSC, WAXD, and FT-IR. The prepared micelles were not stable when they were stored in aqueous dispersion under different condition. Their size increased in the first 20 days and decreased gradually when the storage period was extended. Lyophilization experiment showed that the cryoprotective agent (glucose) was an essential additive to protect the micelles from aggregating during the lyophilization process. After lyophilizing and re-dispersion, the PCL-PEG-PCL micelles became larger in size compared to as-prepared ones. DSC, WAXD, and IR measurements indicated the hydrogen bonding was formed between the hydroxyl group in glucose and the carbonyl group in PCL-PEG-PCL micelles. The effect of added glucose on protection of micelles from aggregation can be explained by the formation of hydrogen bonding with PCL-PEG-PCL micelles and the formation of solid glucose matrix.

Preparation and Characteristics of Chitin-Gelatin Composite Film

2013 ◽  
Vol 690-693 ◽  
pp. 1243-1246
Author(s):  
Ya Juan Wang ◽  
Lan Jiang ◽  
Shuang Xi Shao
Keyword(s):  
Composite Film ◽  
Carbonyl Group ◽  
Gelatin Film ◽  
Hydroxyl Group ◽  
Cross Link ◽  
Denaturation Temperature ◽  
Equilibrium Swelling ◽  
Swelling Rate ◽  
Equilibrium Swelling Ratio ◽  
The Stability

Using hydrogen peroxide as oxidant, the chitin has been oxidized under a certain conditions. And then the IR and SEM of product has been tested, and the results show that hydroxyl group can be transform carbonyl group. What’s more, the oxidation reaction occurred not only in the surface of chitin, but also in its interior. Owing to the reaction of carbonyl group in the oxidation product, this chitin derivatives was applied to cross link with gelatin material, and the properties of modified gelatin film then has been tested. The results of Differential Scanning Calorimeter (DSC) show that the denaturation temperature of composite gelatin film has been enhanced to 109.8°C, and its swelling rate also has been slow, which ensure the stability as a kind of biomaterials, such as microcapsule and microspheres. And the time of native gelatin film achieving equilibrium swelling state is 9 minutes, and the time is 14 minutes for composite film, which means the oxidized chitin can delay the complete swelling rate. And the equilibrium swelling ratio of native gelatin film is larger than that of composite film. Therefore, the composite film will have a good prospects as a kind of potential biomedical.

scholarly journals Zinc-Chelating Compounds as Inhibitors of Human and Bacterial Zinc Metalloproteases

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 56
Author(s):  
Fatema Rahman ◽  
Imin Wushur ◽  
Nabin Malla ◽  
Ove Alexander Høgmoen Åstrand ◽  
Pål Rongved ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Virulence Factors ◽  
Bacterial Infections ◽  
Bacterial Virulence ◽  
Hydroxyl Group ◽  
Matrix Metalloprotease ◽  
Pyridine Nitrogen ◽  
Zinc Metalloproteases ◽  
New Treatment ◽  
Chelating Compounds

Inhibition of bacterial virulence is believed to be a new treatment option for bacterial infections. In the present study, we tested dipicolylamine (DPA), tripicolylamine (TPA), tris pyridine ethylene diamine (TPED), pyridine and thiophene derivatives as putative inhibitors of the bacterial virulence factors thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) and the human zinc metalloproteases, matrix metalloprotease-9 (MMP-9) and matrix metalloprotease-14 (MMP-14). These compounds have nitrogen or sulfur as putative donor atoms for zinc chelation. In general, the compounds showed stronger inhibition of MMP-14 and PLN than of the other enzymes, with Ki values in the lower μM range. Except for DPA, none of the compounds showed significantly stronger inhibition of the virulence factors than of the human zinc metalloproteases. TPA and Zn230 were the only compounds that inhibited all five zinc metalloproteinases with a Ki value in the lower μM range. The thiophene compounds gave weak or no inhibition. Docking indicated that some of the compounds coordinated zinc by one oxygen atom from a hydroxyl or carbonyl group, or by oxygen atoms both from a hydroxyl group and a carbonyl group, and not by pyridine nitrogen as in DPA and TPA.

scholarly journals Microscopic Reaction Mechanism of Formic Acid Generated During Pyrolysis of Cellulosic Insulating Paper

2021 ◽  
Author(s):  
Hanbo Zheng ◽  
Enchen Yang ◽  
Xufan Li ◽  
Tao Yang ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Carbonyl Group ◽  
Thermal Aging ◽  
Aging Process ◽  
Hydroxyl Group ◽  
Main Reaction ◽  
Component Part ◽  
Exponential Factor ◽  
Cellulose Pyrolysis ◽  
Insulating Paper

Abstract Cellulosic insulating paper is the component part of the insulation in power transformers. Under thermal stress inside the transformer, cellulosic insulating paper degrades to generate formic acid that will dissolve in insulating oil. In addition, the generation of formic acid further accelerates the aging process of insulating paper. This study took cellulose molecule with DP of 2 that was composed of D-glucose as the research object, the ReaxFF reaction force field was used to simulate the high temperature thermal aging process of cellulose. This study obtained the main reaction pathways of cellulose pyrolysis to generate formic acid. During the pyrolysis process, the number of formic acid molecules presented short-term fluctuations, which was the phenomenon of disappearance and regeneration of formic acid molecules. The combined element tracing method obtained three pathways of cellulose pyrolysis to generate formic acid: 1) The ether group oxygen atom O5(O'5) and C1(C'1) form a carbonyl group to generate formic acid. 2) Dehydrogenation of the primary alcohol hydroxyl group and the attached C atom form a carbonyl group to generate formic acid. 3) Dehydrogenation of the secondary alcohol hydroxyl group and the attached C atom form a carbonyl group to generate formic acid. Statistics found that the generation of formic acid molecules mainly come from the first pathway. The pre-exponential factor and activation energy of the calculated pyrolysis model were consistent with the experimental results. This study designed the accelerated thermal aging experiment of oil-paper insulation. The silanization derivatization method was used to detect the formic acid generated by the aging of insulating paper, which further verified the feasibility of formic acid as an index for evaluating the aging of cellulosic insulating paper.

Copper-Catalyzed Cross-Dehydrogenative Coupling of α-Hydroxy Esters with Nitromethane

Synlett ◽  
2021 ◽  
Author(s):  
Lili Xiao ◽  
Jin Jiang
Keyword(s):  
Carbonyl Group ◽  
Aldol Reaction ◽  
Coupling Reaction ◽  
Hydroxyl Group ◽  
Dehydrogenative Coupling ◽  
Hydroxy Esters ◽  
Hydroxyl Compounds

An efficient copper-catalyzed tandem oxidation/nitro-aldol reaction of hydroxyl compounds with nucleophiles is developed. In this work, β-nitro-α-hydroxy esters were prepared via cross-dehydrogenative coupling reaction using α-hydroxy esters as hydroxyl compounds and nitromethane as a nucleophile. The reaction is believed to undergo an oxidation of hydroxyl group and then an addition of the generated carbonyl group. It’s an example of CDC reactions related to hydroxyl compounds via carbonyl intermediates.

SYNTHESIS OF VERATROYL ACETALDEHYDE AND INFLUENCE OF A HYDROXYL GROUP ON THE REACTIVITY OF THE PARA-CARBONYL GROUP

1941 ◽  
Vol 19b (1) ◽  
pp. 24-33 ◽  
Author(s):  
Leo Brickman ◽  
W. Lincoln Hawkins ◽  
Harold Hibbert
Keyword(s):  
Carbonyl Group ◽  
Theoretical Explanation ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Methods Of Synthesis

Attempts, by three independent methods of synthesis, to prepare vanilloyl acetaldehyde are described. In each case it has been shown that the presence of a para phenolic hydroxyl group either prevents or alters the normal course of the reactions. The synthesis of veratroyl acetaldehyde has been accomplished, and this product is described. A theoretical explanation for the mutual interrelationship of the carbonyl and para phenolic hydroxyl group is suggested.

Reactions of stabilized phosphoranes with enol lactones

1977 ◽  
Vol 30 (7) ◽  
pp. 1629 ◽  
Author(s):  
PJ Babidge ◽  
RA Massy-Westropp
Keyword(s):  
Double Bond ◽  
Carbonyl Group ◽  
Ester Group ◽  
Carbonyl Groups ◽  
Ketone Group ◽  
Mild Conditions ◽  
Lactone Carbonyl ◽  
Factors Influencing ◽  
Group Reaction

Enol lactones in which the double bond is conjugated with an ester group react with ethoxycarbonyl-methylenetriphenylphosphoraneunder mild conditions to yield the normal Wittig product, derivedfrom the lactone carbonyl group. When the double bond is conjugated with a ketone group reaction occurs at both carbonyl groups. Factors influencing reactivity are discussed.

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