1,721,177 research outputs found
sj-docx-1-chl-10.1177_17475198221090908 – Supplemental material for A convenient route to mono-trans polyunsaturated free fatty acids
No full textSupplemental material, sj-docx-1-chl-10.1177_17475198221090908 for A convenient route to mono-trans polyunsaturated free fatty acids by Fabrizio Vetica, Anna Sansone, Carla Ferreri and Chryssostomos Chatgilialoglu in Journal of Chemical Research</p
A lipophilic “fully-anti” dodecamer from a (5'S)-5',8-cyclo-2'-deoxyguanosine
No full textThe self-assembly of a lipophilic derivative of (5'S)-5',8-cyclo-2'-deoxyguanosine, a mutagenic product formed by hydroxyl radical attack against DNA, has been investigated. This derivative forms, with high fidelity, a dodecameric complex composed of three stacked G-quartets in the presence of strontium picrate. This is the first example of a fully-anti lipophilic G-quadruple
A lipophilic “fully-anti” dodecamer from a (5′S)-5′,8-cyclo-2′-deoxyguanosine
No full textThe self-assembly of a lipophilic derivative of (5'S)-5',8-cyclo-2'-deoxyguanosine, a mutagenic product formed by hydroxyl radical attack against DNA, has been investigated. This derivative forms, with high fidelity, a dodecameric complex composed of three stacked G-quartets in the presence of strontium picrate. This is the first example of a fully-anti lipophilic G-quadruplex
Analysis of the soybean metallothionein system under free radical stress: Protein modification connected to lipid membrane damage
No full textMetallothioneins are small Cys-rich peptides capable of coordinating metal ions, and proposed to be involved in radical stress. The four Zn(ii)-GmMT complexes of soybean (Glycine max) were recombinantly synthesised and exposed to oxidative (HO) and reductive (H atoms and eaq -) stress conditions. Gamma-irradiation was used to simulate the endogenous formation of the reactive species in both aqueous solutions and unsaturated lipid vesicle suspensions, a biomimetic model that showed that tandem protein/lipid damage occurs, in particular under reductive radical stress. This is due to the formation of diffusible sulphur-centred radicals, which migrate from the aqueous phase to the lipid bilayer and are thus able to transform the cis double bond of the oleate moiety into the trans isomer. Among the amino acid residues present in GmMTs, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting metal-clusters to be good interceptors of free radicals. Also Met, Tyr and Phe residues are sensitive amino acid sites of attack under both oxidative and reductive conditions. The modification of the Zn(ii)-GmMT complexes, in particular isoform 2, was monitored by Raman spectroscopy and mass spectrometry. Free radical stress on the Zn(ii)-GmMT complexes is able to induce significant structural changes such as partial deconstruction and/or rearrangement of the metal clusters, but not the complete demetallation of the proteins nor breaking of the backbone, thus confirming their capability to act as protectors under free radical stress conditions. © 2018 The Royal Society of Chemistry
Biomarkers of Oxidative and Radical Stress
No full textReactive oxygen and nitrogen species (ROS/RNS) are generated as a result of normal intracellular metabolism [...
Biological Models of Oxidative Purine DNA Damage in Neurodegenerative Disorders
No full textMost DNA damage caused by oxidative metabolism consists of single lesions that can accumulate in tissues. This review focuses on two classes of lesions: the two 8-oxopurine (8-oxo-Pu) lesions that are repaired by the base excision repair (BER) enzyme and the four 5′,8-cyclopurine (cPu) lesions that are repaired exclusively by the nucleotide excision repair (NER) enzyme. The aim is to correlate the simultaneous quantification of these two classes of lesions in the context of neurological disorders. The first half is a summary of reactive oxygen species (ROS) with particular attention to the pathways of hydroxyl radical (HO•) formation, followed by a summary of protocols for the quantification of six lesions and the biomimetic chemistry of the HO• radical with double-stranded oligonucleotides (ds-ODN) and calf thymus DNA (ct-DNA). The second half addresses two neurodegenerative diseases: xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The quantitative data on the six lesions obtained from genomic and/or mitochondrial DNA extracts across several XP and CS cell lines are discussed. Oxidative stress contributes to oxidative DNA damage by resulting in the accumulation of cPu and 8-oxo-Pu in DNA. The formation of cPu is the postulated culprit inducing neurological symptoms associated with XP and CS
The Tris(trimethylsilyl)silane/Thiol Reducing System: A Tool for Measuring Rate Constants for Reactions of Carbon‐Centered Radicals with Thiols
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