ChemInform Abstract: A Biomimetic Oxidizing System “Cu2+-Ascorbic Acid-O2”: Its Distinctive Hydroxylation Activity of Aromatic Compounds, Reaction Mechanism, and Application to the Synthesis of New Bioactive Molecules

ChemInform ◽  
2010 ◽  
Vol 28 (37) ◽  
pp. no-no
Author(s):  
K. AIHARA ◽  
Y. URANO ◽  
T. HIGUCHI ◽  
M. HIROBE
Keyword(s):  
Ascorbic Acid ◽  
Reaction Mechanism ◽  
Aromatic Compounds ◽  
Bioactive Molecules ◽  
Hydroxylation Activity

Hydroxylation activity of P450 BM-3 mutant F87V towards aromatic compounds and its application to the synthesis of hydroquinone derivatives from phenolic compounds

2004 ◽  
Vol 67 (4) ◽  
pp. 556-562 ◽  
Author(s):  
Woro Triarsi Sulistyaningdyah ◽  
Jun Ogawa ◽  
Qing-Shan Li ◽  
Chiharu Maeda ◽  
Yuki Yano ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Compounds ◽  
Hydroxylation Activity

scholarly journals Kinetic Study on Esterification of Ascorbyl Oleate Catalyzed by Lipase NS 88011

2020 ◽  
Vol 11 (1) ◽  
pp. 8374-8388
Keyword(s):  
Experimental Data ◽  
Ascorbic Acid ◽  
Oleic Acid ◽  
Reaction Mechanism ◽  
Vitamin C ◽  
Kinetic Study ◽  
Immobilized Enzyme ◽  
Molar Ratio ◽  
A Value ◽  
Ping Pong

In this study, bisubstrate kinetics mechanism models were correlated with the experimental data of ascorbyl oleate using the new lipase preparation, Candida antarctica NS 88011, and kinetic parameters (Vmax, Km, and Ki) were estimated. The highest conversion (49.42 %) was observed at 1 h of reaction using the ascorbic acid/oleic acid molar ratio of 1:9, 70 ºC and 30 % of enzymatic loading. The Ping Pong Bi-Bi model showed better congruence with the experimental data for all the effects evaluated. The kinetic constants showed that the lipase had an identical affinity, with a value of 0.81 for both substrates and inhibitory constant (Ki) of ascorbic acid (1.959) much higher than oleic acid (0.0008). It has been demonstrated that lipase has good operational stability (14th cycle). The results obtained with the new immobilized enzyme are valuable to elucidate the reaction mechanism. In addition, it represents an important contribution to optimize the reaction and create strategies to increase the productivity of the esters of vitamin C.

scholarly journals Catalytic Benzolactamization Through Isonitrile Insertion Enabled 1,4-Palladium Shift

2021 ◽  
Author(s):  
Fulin Zhang ◽  
Ruihua Zhao ◽  
Lei Zhu ◽  
Yinghua Yu ◽  
Saihu Liao ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Heterocyclic Compounds ◽  
Bond Activation ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Mechanistic Studies ◽  
Carbon And Nitrogen ◽  
New Methods ◽  
Novel Approach ◽  
Bicyclic System

<b>Isoindolinone is a class of versatile <i>N</i>-heterocycles embedded in many bioactive molecules and natural products. The invention of new methods to synthesize these heterocyclic compounds with easily accessible chemicals is always attractive. Herein, a conceptually novel approach to access this bicyclic system via isonitrile insertion enabled 1,4-pallaidum shift is described. Compared with conventional isonitrile participated C-H bond activation, both carbon and nitrogen atoms in isonitrile moiety are engaged in new bond formation. Notably, two different isoindolinones can be obtained selectively by switching the bases employed. Mechanistic studies including DFT calculations have shed lights on the reaction mechanism and explained the selectivity led to different products. Moreover, the power of current benzolactamization is further demonstrated by providing concise routes to key intermediates of indoprofen, indobufen, aristolactams, lennoxamine and falipamil.</b>

The Nonenzymatic Hydroxylation of Aromatic Compounds by the Ascorbic Acid-H2O2-O2System

1978 ◽  
Vol 42 (12) ◽  
pp. 2281-2284
Author(s):  
Koji Shikata ◽  
Hitoshi Obata ◽  
Tai Tokuyama
Keyword(s):  
Ascorbic Acid ◽  
Aromatic Compounds

scholarly journals Effect of Different Reducing Agents on Aromatic Compounds, Antioxidant and Chromatic Properties of Sauvignon Blanc Wine

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 996 ◽  
Author(s):  
Ana-Marija Jagatić Korenika ◽  
Josipa Biloš ◽  
Bernard Kozina ◽  
Ivana Tomaz ◽  
Darko Preiner ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Aromatic Compounds ◽  
Amino Nitrogen ◽  
White Wine ◽  
Vitis Vinifera L ◽  
Sauvignon Blanc ◽  
Spectrophotometric Methods ◽  
Basic Parameters ◽  
Chromatic Properties ◽  
The Impact

Sulfur dioxide (SO2) is widely the most used enological additive with reductive, antiseptic and dissolving properties. According to increasing health concerns and the gradual decrease in total SO2 concentrations allowed in wine, alternative and supplementary agents for preservation are being investigated. For this reason, the current study was focused on the impact of different commercial reductive agents on white wine antioxidant activity and chemical composition. The effect of additives that combine sulfites, ascorbic acid and enological tannins were compared against standard 5% sulfurous acid (H2SO3) during the pre-fermentative treatments of Sauvignon Blanc must (Vitis vinifera L.). The basic parameters of quality, free amino-nitrogen and total polyphenoliccompounds in must were analyzed. Gas chromatography and spectrophotometric methods were used to investigate the overall volatile composition, antioxidant and chromatic parameters in wines. The obtained results undoubtedly pointed out the positive effect of sulfuric acid on the fermentation dynamics. Furthermore, application of combined reducing additives with potassium metabisulfite, L-ascorbic acid, gallotannins and ellagitannins, resulted in a higher antioxidant capacity and increased concentration of aromatic compounds and their odor activity values in Sauvignon Blanc wine.

scholarly journals Catalytic Benzolactamization Through Isonitrile Insertion Enabled 1,4-Palladium Shift

2021 ◽  
Author(s):  
Fulin Zhang ◽  
Ruihua Zhao ◽  
Lei Zhu ◽  
Yinghua Yu ◽  
Saihu Liao ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Heterocyclic Compounds ◽  
Bond Activation ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Mechanistic Studies ◽  
Carbon And Nitrogen ◽  
New Methods ◽  
Novel Approach ◽  
Bicyclic System

<b>Isoindolinone is a class of versatile <i>N</i>-heterocycles embedded in many bioactive molecules and natural products. The invention of new methods to synthesize these heterocyclic compounds with easily accessible chemicals is always attractive. Herein, a conceptually novel approach to access this bicyclic system via isonitrile insertion enabled 1,4-pallaidum shift is described. Compared with conventional isonitrile participated C-H bond activation, both carbon and nitrogen atoms in isonitrile moiety are engaged in new bond formation. Notably, two different isoindolinones can be obtained selectively by switching the bases employed. Mechanistic studies including DFT calculations have shed lights on the reaction mechanism and explained the selectivity led to different products. Moreover, the power of current benzolactamization is further demonstrated by providing concise routes to key intermediates of indoprofen, indobufen, aristolactams, lennoxamine and falipamil.</b>

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