- Beyond DPPH: Use of Fluorescence-Enabled Inhibited Autoxidation to Predict Oxidative Cell Death Rescue
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“Antioxidant activity” is an often invoked, but generally poorly characterized, molecular property. Several assays are available to determine antioxidant activity, the most popular of which is based upon the ability of a putative antioxidant to reduce 2,2
- Shah, Ron,Farmer, Luke A.,Zilka, Omkar,Van Kessel, Antonius T.M.,Pratt, Derek A.
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- Aerobic and hydrolytic decomposition of pseudotetrahedral nickel phenolate complexes
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Pseudotetrahedral nickel(II) phenolate complexes TpR,MeNi-OAr (TpR,Me = hydrotris(3-R-5-methylpyrazol-1-yl)borate; R = Ph {1a}, Me {1b}; OAr = O-2,6-iPr2C6H3) were synthesized as models for nickel-substituted copper amine oxidase apoenzyme, which utilizes an N3O (i.e., His3Tyr) donor set to activate O2 within its active site for oxidative modification of the tyrosine residue. The bioinspired synthetic complexes 1a,b are stable in dilute CH2Cl2 solutions under dry anaerobic conditions, but they decompose readily upon exposure to O2 and H2O. Aerobic decomposition of 1a yields a range of organic products consistent with formation of phenoxyl radical, including 2,6-diisopropyl-1,4-benzoquinone, 3,5,3′,5′-tetraisopropyl-4,4′-diphenodihydroquinone, and 3,5,3′,5′-tetraisopropyl-4,4′-diphenoquinone, which requires concurrent O2 reduction. The dimeric product complex di[hydro{bis(3-phenyl-5-methylpyrazol-1-yl)(3-ortho-phenolato-5-methylpyrazol-1- yl)borato}nickel(II)] (2) was obtained by ortho C-H bond hydroxylation of a 3-phenyl ligand substituent on 1a. In contrast, aerobic decomposition of 1b yields a dimeric complex [TpMe,MeNi]2(μ-CO3) (3) with unmodified ligands. However, a unique organic product was recovered, assigned as 3,4-dihydro-3,4-dihydroxy-2,6-diisopropylcyclohex-5-enone on the basis of 1H NMR spectroscopy, which is consistent with dihydroxylation (i.e., addition of H2O2) across the meta and para positions of the phenol ring. Initial hydrolysis of 1b yields free phenol and the known complex [TpMe,MeNi(μ-OH)]2, while hydrolysis of 1a yields an uncharacterized intermediate, which subsequently rearranges to the new sandwich complex [(TpPh,Me)2Ni] (4). Autoxidation of the released phenol under O2 was observed, but the reaction was slow and incomplete. However, both 4 and the in situ hydrolysis intermediate derived from 1a react with added H2O2 to form 2. A mechanistic scheme is proposed to account for the observed product formation by convergent oxygenation and hydrolytic autoxidation pathways, and hypothetical complex intermediates along the former were modeled by DFT calculations. All new complexes (i.e., 1a,b and 2-4) were fully characterized by FTIR, 1H NMR, and UV-vis-NIR spectroscopy and by X-ray crystallography.
- Deb, Tapash,Rohde, Gregory T.,Young, Victor G.,Jensen, Michael P.
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- COMPOUND FOR THE PROPHYLAXIS OR TREATMENT OF ORGAN DAMAGE
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The present invention relates to compounds for prophylaxis or treatment of organ damage by restoring endothelial function and/or inhibiting reactive oxygen species production and especially to compounds for prophylaxis or treatment of diabetic kidney dama
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Page/Page column 10; 11; 14
(2016/12/22)
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- 6-HYDROXY-2,5,7,8-TETRAMETHYLCHROMAN-COMPOUNDS FOR THE TREATMENT OF CHRONIC OBSTRUCTIVE AIRWAY DISEASES
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The present invention relates to compounds for the treatment of chronic obstructive airway diseases such as chronic obstructive pulmonary disease (COPD) or asthma or bronchiectasis. The present invention further relates to drug delivery devices suitable t
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Page/Page column 17-18
(2016/05/24)
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- COMPOUNDS FOR PROTECTION OF CELLS
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This invention is related to a compound with the structural formula (I). Wherein, R1, and R2 are independently selected from the group consisting of C1-C6 alkyl and is preferably methyl, ethyl, propyl or isopropyl; R3 is selected fro
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Page/Page column 34-35; 40
(2014/07/08)
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- PROCESS FOR THE PREPARATION OF HYDROQUINONES
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The invention relates to a process for the preparation of a hydroquinone compound of formula (I) wherein R2, R3, R5 and R6 have the meaning according to claim 1, with the steps of formylating a substituted phenol and oxidising the resulting substituted 4-hydroxy- benzaldehyde under acidic conditions to the corresponding hydroquinone of formula (I). Another object of the invention concerns the intermediate 2,3,5-trimethyl-4-hydroxy- benzaldehyde for synthesis of 2,3,5-trimethyl-hydroquinone (TMHQ) and (dl)cc-tocopherol.
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Page/Page column 18-19
(2011/11/01)
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- Isotopic effect study of propofol deuteration on the metabolism, activity, and toxicity of the anesthetic
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The use of isotopic substitution to delay the oxidative metabolism of the anesthetic propofol 1 was studied. The aromatic hydrogens of propofol 1 were replaced by deuterium to produce the mono- and trideuterated derivatives 4 and 5. In vitro metabolic stu
- Helfenbein,Lartigue,Noirault,Azim,Legailliard,Galmier,Madelmont
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p. 5806 - 5808
(2007/10/03)
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