Proton-Coupled Electron Transfer and Hydrogen Tunneling in Olive Oil Phenol Reactions DOI Open Access

Jelena Torić,

Ana Marković,

Stipe Mustać

et al.

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(12), P. 6341 - 6341

Published: June 7, 2024

Olive oil phenols are recognized as molecules with numerous positive health effects, many of which rely on their antioxidative activity, i.e., the ability to transfer hydrogen radicals. Proton-coupled electron reactions and tunneling ubiquitous in biological systems. Reactions olive phenols, hydroxytyrosol, tyrosol, oleuropein, oleacein, oleocanthal, homovanillyl alcohol, vanillin, a few phenolic acids DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical 1,4-dioxane:water = 95:5 or 99:1 v/v solvent mixture were studied through an experimental kinetic analysis computational chemistry calculations. The highest rate constants corresponding activity obtained for ortho-diphenols oleacein. experimentally determined isotope effects (KIEs) caffeic acid 16.0, 15.4, 16.7, respectively. Based these KIEs, thermodynamic activation parameters, intrinsic bond orbital (IBO) along IRC path calculations, we propose proton-coupled mechanism. average local ionization energy donor Fukui function compounds show that most reactive electron-donating sites associated π electrons above below aromatic ring, support IBO proposed PCET reaction Large KIEs isotopic values Arrhenius pre-exponential factor AH/AD 0.6, 1.3, 0.3, respectively, reveal involvement process.

Language: Английский

An Active Site Tyr Residue Guides the Regioselectivity of Lysine Hydroxylation by Nonheme Iron Lysine-4-hydroxylase Enzymes through Proton-Coupled Electron Transfer DOI Creative Commons
Yuanxin Cao, Sam Hay, Sam P. de Visser

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(17), P. 11726 - 11739

Published: April 18, 2024

Lysine dioxygenase (KDO) is an important enzyme in human physiology involved bioprocesses that trigger collagen cross-linking and blood pressure control. There are several KDOs nature; however, little known about the factors govern regio- stereoselectivity of these enzymes. To understand how can selectively hydroxylate their substrate, we did a comprehensive computational study into mechanisms features 4-lysine dioxygenase. In particular, selected snapshot from MD simulation on KDO5 created large QM cluster models (A, B, C) containing 297, 312, 407 atoms, respectively. The largest model predicts regioselectivity matches experimental observation with rate-determining hydrogen atom abstraction C4–H position, followed by fast OH rebound to form 4-hydroxylysine products. calculations show C, dipole moment positioned along bond substrate and, therefore, electrostatic electric field perturbations protein assist creating hydroxylation selectivity. Furthermore, active site Tyr233 residue identified reacts through proton-coupled electron transfer akin axial Trp cytochrome c peroxidase. Thus, upon formation iron(IV)-oxo species catalytic cycle, phenol loses proton nearby Asp179 residue, while at same time, transferred iron create iron(III)-oxo species. This charged tyrosyl directs guides selectivity C4-hydroxylation substrate.

Language: Английский

Citations

13
Concerted Proton Electron Transfer or Hydrogen Atom Transfer? An Unequivocal Strategy to Discriminate these Mechanisms in Model Systems DOI Creative Commons
Davide Zeppilli, Laura Orian

Physical Chemistry Chemical Physics, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The combination of intrinsic bond orbital and activation strain analysis allows the correct identification rationalization operative mechanism between HAT CPET, while singly occupied molecular does not fit in this picture.

Language: Английский

Citations

0
Cyclization Through Dual C(sp3)−H Functionalization DOI
Masoud Sadeghi

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(17), P. 3542 - 3563

Published: July 11, 2024

Abstract C( sp 3 )−H functionalization methods have been widely employed in many organic transformations such as cyclization reactions, heterocycle synthesis, cross‐coupling protocols, and photochemical transformations. Among these transformations, reaction through offers a direct route to convert simple linear substrates complex products. There are three common modes of utilizing bonds reactions including single, double, dual functionalization. As the most challenging mode, refers converting two separate one molecule into desired C−Z which can be reactions. Cyclization via classified based on C−H reactivities. Therefore, categorized classes types activated‐activated, activated‐unactivated, unactivated‐unactivated bonds. Most published reports for involve activated‐activated However, number reported papers other has growing. This review focuses protocols used categorizes

Language: Английский

Citations

2
14‐Membered Macrocyclic β‐Diiminato Gold(II) – A New Member for the Gold(II) Complex Family? DOI Creative Commons

Lukas Sorge,

J. T. Link,

Katja Heinze

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(34)

Published: April 16, 2024

The chemistry of molecular gold compounds is dominated by the oxidation states +I and +III. For intermediate state +II with 5d

Language: Английский

Citations

1
Proton-Coupled Electron Transfer and Hydrogen Tunneling in Olive Oil Phenol Reactions DOI Open Access

Jelena Torić,

Ana Marković,

Stipe Mustać

et al.

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(12), P. 6341 - 6341

Published: June 7, 2024

Olive oil phenols are recognized as molecules with numerous positive health effects, many of which rely on their antioxidative activity, i.e., the ability to transfer hydrogen radicals. Proton-coupled electron reactions and tunneling ubiquitous in biological systems. Reactions olive phenols, hydroxytyrosol, tyrosol, oleuropein, oleacein, oleocanthal, homovanillyl alcohol, vanillin, a few phenolic acids DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical 1,4-dioxane:water = 95:5 or 99:1 v/v solvent mixture were studied through an experimental kinetic analysis computational chemistry calculations. The highest rate constants corresponding activity obtained for ortho-diphenols oleacein. experimentally determined isotope effects (KIEs) caffeic acid 16.0, 15.4, 16.7, respectively. Based these KIEs, thermodynamic activation parameters, intrinsic bond orbital (IBO) along IRC path calculations, we propose proton-coupled mechanism. average local ionization energy donor Fukui function compounds show that most reactive electron-donating sites associated π electrons above below aromatic ring, support IBO proposed PCET reaction Large KIEs isotopic values Arrhenius pre-exponential factor AH/AD 0.6, 1.3, 0.3, respectively, reveal involvement process.

Language: Английский

Citations

1