Linoleic acid peroxidation vs. isomerization: a biomimetic model of free radical reactivity in the presence of thiols

2011 ◽  
Vol 9 (9) ◽  
pp. 3541 ◽  
Author(s):  
Branka Mihaljević ◽  
Ivana Tartaro ◽  
Carla Ferreri ◽  
Chryssostomos Chatgilialoglu
Keyword(s):  
Linoleic Acid ◽  
Free Radical ◽  
Radical Reactivity

Recent advances in Minisci-type reactions and applications in organic synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Wengui Wang ◽  
Shoufeng Wang
Keyword(s):  
Free Radical ◽  
Hydrogen Atom ◽  
Organic Synthesis ◽  
Radical Reactivity ◽  
Atom Loss ◽  
Radical Generation ◽  
In Situ Generation ◽  
Thermal Cleavage ◽  
Synthetic Chemist

Abstract:: Minisci-type reactions have become widely known as reactions that involve the addition of carbon-centered radicals to basic heteroarenes followed by formal hydrogen atom loss. While the originally developed protocols for radical generation remain in active use today, in recent years by a new array of radical generation strategies allow use of a wider variety of radical precursors that often operate under milder and more benign conditions. New transformations based on free radical reactivity are now available to a synthetic chemist looking to utilize a Minisci-type reaction. Radical-generation methods based on photoredox catalysis and electrochemistry, which utilize thermal cleavage or the in situ generation of reactive radical precursors, have become popular approaches. Our review will cover the remarkably literature that has appeared on this topic in recent 5 years, from 2015-01 to 2020-01, in an attempt to provide guidance to the synthetic chemist, on both the challenges that have been overcome and applications in organic synthesis.

Hydroxyl free radical reactivity toward aqueous chlorinated phenols

2005 ◽  
Vol 39 (5) ◽  
pp. 865-869 ◽  
Author(s):  
Julio A. Zimbron ◽  
Kenneth F. Reardon
Keyword(s):  
Free Radical ◽  
Chlorinated Phenols ◽  
Radical Reactivity ◽  
Hydroxyl Free Radical

scholarly journals Antiradical and Cytotoxic Activities of Varying Polarity Extracts of the Aerial Part ofEuphorbia hirtaL.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Shanmugapriya Perumal ◽  
Roziahanim Mahmud ◽  
Suthagar Pillai Piaru ◽  
Wei Cai Lee ◽  
Surash Ramanathan
Keyword(s):  
Linoleic Acid ◽  
Free Radical ◽  
Aerial Part ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Total Phenolic ◽  
Cytotoxic Activities ◽  
Uv Spectrophotometry ◽  
Etoh Extract

Euphorbia hirtais a well-known ethnomedicinal plant with diverse biological activities. The aim of the present study is to investigate the antiradical activities of various solvent extracts of the aerial part ofE. hirtaas well as to determine the possible cytotoxicity of these extracts. The aerial part ofE. hirtawas extracted with different solvent systems in order to increase polarity. The solvents used were hexane, dichloromethane (DCM), ethyl acetate (EA), ethanol (EtOH), and methanol (MeOH). The contents of total phenols and total flavonoids were analyzed by UV spectrophotometry, whereas the potential free radical-scavenging activities of the extracts were evaluated using the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), theβ-carotene-linoleic acid bleaching system, and reducing power. The EtOH extract exhibited the highest total phenolic content (237.9±2.26 mg GAE/g), and DCM extract scored the highest total flavonoid content (121±0.15 mg CE/g). The MeOH extract showed a potent free radical-scavenging activity as evidenced by low EC50at 42.81 µg/mL. Interestingly, the EtOH extract demonstrated the highest reducing power activity with EC50value of 6.18 µg/mL. Inβ-carotene-linoleic acid assay, oxidation of linoleic acid was effectively inhibited by DCM extract with96.15±0.78%. All the extracts showed no cytotoxic activity against Vero cells.

scholarly journals Free Radical Reactivity of a Phosphaalkene Explored Through Studies of Radical Isotopologues

2018 ◽  
Vol 58 (1) ◽  
pp. 297-301 ◽  
Author(s):  
Lalangi Chandrasena ◽  
Kerim Samedov ◽  
Iain McKenzie ◽  
Mina Mozafari ◽  
Robert West ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Reactivity

scholarly journals Pengaruh Penambahan Rempah dan Bentuk Minuman terhadap Aktivitas Antioksidan Berbagai Minuman Tradisional Indonesia

2017 ◽  
Vol 37 (1) ◽  
pp. 7 ◽  
Author(s):  
Aisyah Tri Septiana ◽  
Mohammad Samsi ◽  
Mustaufik Mustaufik
Keyword(s):  
Antioxidant Activity ◽  
Linoleic Acid ◽  
Free Radical ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Phenolic Contents ◽  
Beverage Type ◽  
Radical Trapping ◽  
Palm Sugar

Indonesia traditional beverages such as minuman jahe, kunyit asam, beras kencur, and minuman temulawak are usually made with the addition of spices. They can be served in the form of  liquid or powder. This research was aimed to study the effect of  the beverage type, addition of spices, and the form of product on their antioxidant activity. The type of sugar used in this study was palm sugar juice. Total phenolic contents were measured to  indicate the level of antioxidants. Measurement of antioxidant  activity was conducted by analyzing malonaldehyde from linoleic  acid and capturing capacity of DPPH radical. The results showed  that Indonesian traditional beverage could inhibit the oxidation of linoleic acid and capture free radicals. Free radical capturing  capacity of curcuma beverage greater than other beverages, but  the malonaldehyde (MDA) inhibitor effect was not different. Total phenolic content of curcuma tended to be higher than the other traditional beverages. The addition of spices could raise the level  of total phenolic content in beverages and increase free radical  trapping capacity. Drying the beverages into powder could reduce the levels of total phenolic content and but did not reduce the  antioxidant activity. ABSTRAKMinuman tradisional Indonesia seperti minuman jahe, kunyit  asam, beras kencur, dan minuman temulawak biasanya dibuat  dengan tambahan berbagai rempah. Minuman tersebut dapat  disajikan dalam bentuk cair maupun serbuk. Penelitian ini  bertujuan untuk mengetahui pengaruh jenis minuman,  penambahan rempah tambahan, dan bentuk minuman terhadap aktivitas antioksidan minuman. Jenis gula yang ditambahkan  adalah gula nira. Jenis antioksidan yang diuji adalah total fenolik. Pengukuran aktivitas antioksidan dilakukan dengan uji  penghambatan malonaldehid dan kapasitas penangkapan radikal  DPPH. Hasil penelitian menunjukkan bahwa minuman  tradisional Indonesia dapat menghambat oksidasi asam linoleat dan menangkap radikal bebas. Kapasitas penangkapan radikal  bebas oleh minuman temulawak lebih besar dibandingkan  minuman yang lain tetapi kemampuan penghambatan  malonaldehid (MDA) oleh minumaan tradisional tidak berbeda.  Total fenolik minuman temulawak cenderung lebih besar  dibandingkan minuman tradisional yang lain. Penambahan  rempah-rempah dapat meningkatkan kadar total fenolik  minuman dan meningkatkan kapasitas penangkapan radikal  bebas. Pembuatan minuman serbuk pada penelitian ini dapat  menurunkan kadar total fenolik tetapi tidak menurunkan aktivitas antioksidan.

Sign in / Sign up

Export Citation Format

Share Document