Ascorbic Acid Promoted Oxidative Arylation of Vinyl Arenes to 2-Aryl Acetophenones without Irradiation at Room Temperature under Aerobic Conditions

2015 ◽  
Vol 80 (15) ◽  
pp. 7739-7745 ◽  
Author(s):  
Biju Majhi ◽  
Debasish Kundu ◽  
Brindaban C. Ranu
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Aerobic Conditions

THE APPLICATION OF NATURAL AND SYNTHETIC ANTIOXIDANTS TO INCREASE THE OXIDATION RESISTANCE OF LINSeED OIL

2020 ◽  
Vol 13 (4(50)) ◽  
pp. 41-51
Author(s):  
I. P. Edimecheva ◽  
A. A. Sosnovskaya ◽  
O. I. Shadyro
Keyword(s):  
Ascorbic Acid ◽  
Kinetic Data ◽  
Room Temperature ◽  
Linseed Oil ◽  
Ascorbyl Palmitate ◽  
Natural Antioxidants ◽  
Oxidation Products ◽  
Free Access ◽  
Synthetic Antioxidants ◽  
Acid Esters

The effectiveness of several synthetic and natural antioxidants (AO) in inhibiting the oxidation of linseed oil has been studied. Under the conditions of accelerated oxidation at 100 °С, the values of the induction period of oxidation and stabilization factors of linseed oil in the presence of additives of known phenolic AOs, tocopherols, fat-soluble ascorbic acid esters and compositions based on them were determined. The data obtained indicate that ascorbic acid esters effectively inhibit the oxidation of linseed oil. The stabilizing effect of ascorbyl palmitate (AP) increases with an elevation in the content of α-linolenic acid in the oil and a decrease in the oxidative stability of the oil. One AP provided better stabilization efficiency than some known compositions based on it. Kinetic data on the accumulation of oxidation products in linseed oil with AP additives during the storage at room temperature and with free access of the air were obtained, demonstrating high inhibiting activity of AP under these conditions, which provides a possibility to increase the shelf life of the stabilized oil up to 18 months or more.

The preventing method of browning and γ-aminobutyric acid (GABA) contained in Luffa cylindrica Roem. cultivated in Okinawa

2021 ◽  
Vol 4 (4) ◽  
pp. 251-258
Author(s):  
Hanagasaki Takashi ◽  
Keyword(s):  
Ascorbic Acid ◽  
Acid Solution ◽  
Room Temperature ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Luffa Cylindrica ◽  
Air Exposure ◽  
Ascorbic Acid Solution ◽  
Gaba Content ◽  
Prevention Method

Luffa (Luffa cylindrica Roem.) is a popular vegetable in Okinawa, and it has abundant nutrients, including γ-aminobutyric acid (GABA). We focused on GABA content in luffa, taking into consideration registering it as foods with functional claims in Japan. Besides, when selling cut luffa and frozen cut luffa at supermarkets, they are supposed to get browned due to air exposure and other causes. In the present study, we developed the prevention method of browning cut luffa and frozen cut luffa using 0.5 %, 1.0 %, 2.0 %, and 4.0 % ascorbic acid solution. It was found that 55 L of 4.0 % ascorbic acid solution could be used for soaking of 70 kg cut luffa to prevent browning, but GABA content decreased in food processing of luffa in the factory. Besides, GABA content in luffa fruits was found not to change during storage for 07 days at room temperature after harvest.

Preparation of Green Nanosilver by Ascorbic Acid and its Spectral Properties

2013 ◽  
Vol 749 ◽  
pp. 503-506
Author(s):  
Yang He Luo ◽  
Chun Ming Wang ◽  
Wen Qing Yin ◽  
Ai Hui Liang
Keyword(s):  
Ascorbic Acid ◽  
Spectral Properties ◽  
Room Temperature ◽  
Rayleigh Scattering ◽  
Resonance Rayleigh Scattering ◽  
Visible Spectroscopy ◽  
Laser Scattering ◽  
Transmission Electron ◽  
Uv Visible ◽  
Strong Absorption Peak

In the presence of stabilizer of citrate and room temperature, stable green nanosilver sol was prepared by reduction of AgNO3by ascorbic acid. It was characterized by UV-visible spectroscopy, resonance Rayleigh scattering (RRS) spectroscopy, laser scattering and transmission electron microscopy. Results showed that the nanosilver sol exhibited a RRS peak at 496 nm, a strong absorption peak at 414 nm and the particle size is 12 nm.

scholarly journals Modelling ascorbic acid thermal degradation and browning in orange juice under aerobic conditions

2001 ◽  
Vol 36 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Maria C. Manso ◽  
Fernanda A.R. Oliveira ◽  
Jorge C. Oliveira ◽  
Jesus M. Frias
Keyword(s):  
Ascorbic Acid ◽  
Thermal Degradation ◽  
Orange Juice ◽  
Aerobic Conditions

ChemInform Abstract: Very Fast Suzuki-Miyaura Reaction Catalyzed by Pd(OAc)2under Aerobic Conditions at Room Temperature in EGME/H2O.

ChemInform ◽  
2009 ◽  
Vol 40 (20) ◽  
Author(s):  
Alessandro Del Zotto ◽  
Francesco Amoroso ◽  
Walter Baratta ◽  
Pierluigi Rigo
Keyword(s):  
Room Temperature ◽  
Aerobic Conditions

EFFETS DE L'ACIDE ASCORBIQUE SUR PLUSIEURS VARIABLES BIOLOGIQUES NORMALEMENT AFFECTÉES PAR LE FROID

1949 ◽  
Vol 27e (6) ◽  
pp. 349-363 ◽  
Author(s):  
M. Thérien ◽  
J. Leblanc ◽  
O. Héroux ◽  
L. P. Dugal
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Room Temperature ◽  
Experimental Studies ◽  
The Other ◽  
Histamine Content ◽  
Exposure To Cold ◽  
Thymus Atrophy ◽  
Subsequent Administration ◽  
Made In

It has been shown recently by Dugal and Thérien that during a short or long exposure to cold, the normal hypertrophy of the adrenals is completely prevented by large doses of ascorbic acid, and that, nevertheless, at the same time, resistance is increased towards the same damaging agent. So, the most universally accepted criterion of damage caused by stress is abolished when the animals exposed to cold receive large doses of ascorbic acid. Starting from that observation, it was natural to wonder what would be the effects of the ascorbic acid on the biological changes normally associated with the hypertrophy of the adrenals during exposure to cold. The present paper describes the experimental studies made in that connection; the results obtained show that: (1) ascorbic acid (a) partly inhibits the thymus atrophy normally encountered upon exposure to any stress including cold, (b) accelerates in a very significant way the enlargement of the thyroid, (c) is responsible for an increase in weight of the spleen, whereas the control animals, on the contrary, show a decrease in weight of the same organ; (2) the histamine content of the adrenals, which increases at room temperature under the influence of ascorbic acid, is significantly decreased during exposure to cold under the influence of the same substance; (3) the activity of the adrenals, far from being inhibited by ascorbic acid is even increased if the cholesterol changes are taken as an index of that activity; (4) the initial hypotension—due to cold—found in our controls, is prevented by large doses of ascorbic acid; on the other hand, if hypertension develops after long exposure to cold, the subsequent administration of large doses of ascorbic acid restores the blood pressure to normal. Confirmation has also been obtained for the previously reported observation that ascorbic acid prevents the hypertrophy of the adrenals during exposure to cold.

Ascorbic acid promoted [4 + 2] benzannulation: a mild, operationally simple approach to the synthesis of phenanthrenes

2016 ◽  
Vol 3 (5) ◽  
pp. 630-634 ◽  
Author(s):  
Mei-jie Bu ◽  
Guo-ping Lu ◽  
Chun Cai
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Simple Approach

Ascorbic acid-promoted radical [4 + 2] benzannulation for the generation of substituted phenanthrenes at room temperature has been developed.

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