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E Damiani

Publications and source records attributed to E Damiani.

At least 19 recordsLinked to original sources
PubMed2003

Treatment of mountain refuge wastewater by fixed and moving bed biofilm systems.

Tourists visiting mountain refuges in the Alps have increased significantly in the last decade and the number of refuges and huts at high altitude too. In this research the results of an intensive monitoring of a wastewater treatment plant (WWTP) for a tourist mountain refuge located at 2,981 m a.s.l. are described. Two biofilm reactors were adopted: (a) a Moving Bed Biofilm Reactor (MBBR); (b) a submerged Fixed Bed Biofilm Reactor (FBBR). The aims of this research were: (i) the evaluation of the main parameters characterising the processes and involved in the design of the wastewater plants, in order to compare advantages and disadvantages of the two tested alternatives; (ii) the acquisition of an adequate knowledge of the problems connected with the wastewater treatment in alpine refuges. The main results have been: (i) a quick start-up of the biological reactors obtainable thanks to a pre-colonization before the transportation of the plastic carriers to the refuge at the beginning of the tourist season; (ii) low volume and area requirement; (iii) significantly higher removal efficiency compared to other fixed biomass systems, such as trickling filters, but the energy consumption is higher.

Altitude↗
PubMed2001

Ca(2+)-dependent interaction of triadin with histidine-rich Ca(2+)-binding protein carboxyl-terminal region.

A direct binding of HRC (histidine-rich Ca(2+)-binding protein) to triadin, the main transmembrane protein of the junctional sarcoplasmic reticulum (SR) of skeletal muscle, seems well supported. Opinions are still divided, however, concerning the triadin domain involved, either the cytoplasmic or the lumenal domain, and the exact role played by Ca(2+), in the protein-to-protein interaction. Further support for colocalization of HRC with triadin cytoplasmic domain is provided here by experiments of mild tryptic digestion of tightly sealed TC vesicles. Accordingly, we show that HRC is preferentially phosphorylated by endogenous CaM K II, anchored to SR membrane on the cytoplasmic side, and not by lumenally located casein kinase 2. We demonstrate that HRC can be isolated as a complex with triadin, following equilibrium sucrose-density centrifugation in the presence of mM Ca(2+). Here, we characterized the COOH-terminal portion of rabbit HRC, expressed and purified as a fusion protein (HRC(569-852)), with respect to Ca(2+)-binding properties, and to the interaction with triadin on blots, as a function of the concentration of Ca(2+). Our results identify the polyglutamic stretch near the COOH terminus, as the Ca(2+)-binding site responsible, both for the acceleration in mobility of HRC on SDS-PAGE in the presence of millimolar concentrations of Ca(2+), and for the enhancement by high Ca(2+) of the interaction between HRC and triadin cytoplasmic segment. (c)2001 Elsevier Science.

Animals↗
PubMed2001

Clues to calcineurin function in mammalian fast-twitch muscle.

It is believed that brief, high amplitude Ca2+ transients, as found in fast-twitch muscles, are not sufficient to activate the calcineurin (Cn)-dependent signaling pathway involved in regulation of slow myosin and slow sarcoplasmic reticulum Ca2+-ATPase genes (Olson and Williams, Cell 101: 689-692, 2000). The results reported here try to fill the gap between this molecular knowledge, and the still fragmentary pieces of information on a possible different role of calcineurin in the same type of muscles. In the present work calcineurin was determined immunocytochemically by labeling fast- and slow-twitch fibers of representative rabbit muscles with anti-CnB antibodies, and was assessed by western blotting of isolated subcellular fractions. Calcineurin was found to be largely soluble and to be constitutively overexpressed in fast muscle as CnAalpha and CnAbeta isoforms, the latter appearing to be predominant. Particulate calcineurin was not only associated with myofibrils but also with membranes of various origins. Fluorescence microscopy showed that calcineurin was distributed in the same pattern with respect to sarcomeres in both types of fibers, and formed punctate dots spanning the I-Z-I region, rather than being exclusively located at the Z-line, a disposition described for cardiomyocytes (Frey et al., Proc Natl Acad Sci USA 97: 14,632-14,637, 2000). From knowledge that, in mammalian skeletal muscle fibers, junctional triads are located at the A-I band boundary, we explored the distribution of calcineurin between triadic components, after having verified that it was present in very low amounts in dystrophin-enriched sarcolemmal membranes. Our results demonstrate that a small but significant proportion of calcineurin coenriched with transverse tubules (TT), and copurified with the DHPR and with DHPR-associated PKA-AKAP15/18, thus suggesting that it is assembled as a multiprotein complex in the junctional membrane domain of TT. The membrane specificity of this association is further corroborated by the negative evidence for the presence of calcineurin in SR terminal cisternae. Calcineurin was separated from the DHPR and isolated as a AKAP15/18 subcomplex, including beta2 adrenergic receptor, in addition to PKA and calcineurin, following equilibrium centrifugation of detergent extracts on a linear sucrose gradient. We show that the alpha1 subunit skeletal isoform of the DHPR, is a substrate for calcineurin dephosphorylation, after previous phosphorylation by endogenous PKA.

Animals↗
PubMed2001

Phosphorylation of the triadin cytoplasmic domain by CaM protein kinase in rabbit fast-twitch muscle sarcoplasmic reticulum.

Skeletal muscle triadin is a sarcoplasmic reticulum (SR) membrane protein that had been shown to interact structurally and functionally at the cytoplasmic domain (amino acid residues 1-47) with the ryanodine receptor (RyR1), and to undergo phosphorylation by endogenous calmodulin protein kinase (CaM K II) in isolated terminal cisternae from rabbit fast-twitch muscle. Here we show that triadin cytoplasmic domain expressed as glutathione-S-transferase fusion protein, is a substrate of the protein kinase. This finding is corroborated by identification of a specific consensus sequence in the deduced amino sequence between residue 34 and 37 of triadin. Confirming the regulatory features of CaM K II, we show the phosphorylation of triadin cytoplasmic segment by the kinase, when converted to the autonomous form. We propose that triadin modulates RyR1 in a phosphorylation-dependent manner.

Animals↗
PubMed2000

Phosphorylation of anchoring protein by calmodulin protein kinase associated to the sarcoplasmic reticulum of rabbit fast-twitch muscle.

Regulatory phosphorylation of phospholamban and of SR Ca(2+)-ATPase SERCA2a isoform by endogenous CaM-K II in slow-twitch skeletal and cardiac sarcoplasmic reticulum (SR) is well documented, but much less is known of the exact functional role of CaM K II in fast-twitch muscle SR. Recently, it was shown that RNA splicing of brain-specific alpha CaM K II, gives rise to a truncated protein (alpha KAP), consisting mainly of the association domain, serving to anchor CaM K II to SR membrane in rat skeletal muscle [Bayer, K.-U., et al. (1998) EMBO J. 19, 5598-5605]. In the present study, we searched for the presence of alpha KAP in sucrose-density purified SR membrane fractions from representative fast-twitch and slow-twitch limb muscles, both of the rabbit and the rat, using immunoblot techniques and antibody directed against the association domain of alpha CaM K II. Putative alpha KAP was immunodetected as a 23-kDa electrophoretic component on SDS-PAGE of the isolated SR from fast-twitch but not from slow-twitch muscle, and was further identified as a specific substrate of endogenous CaM K II, in the rabbit. Immunodetected, (32)P-labeled, non-calmodulin binding protein, behaved as a single 23-kDa protein species under several electrophoretic conditions. The 23-kDa protein, with defined properties, was isolated as a complex with 60-kDa delta CaM K II isoform, by sucrose-density sedimentation analysis. Moreover, we show here that putative alphaKAP, in spite of its inability to bind CaM in ligand blot overlay, co-eluted with delta CaM K II from CaM-affinity columns. That raises the question of whether CaM K II-mediated phosphorylation of alpha KAP and triadin together might be involved in a molecular signaling pathway important for SR Ca(2+)-release in fast-twitch muscle SR.

Animals↗
PubMed2000

Coordinate expression of Ca2+-ATPase slow-twitch isoform and of beta calmodulin-dependent protein kinase in phospholamban-deficient sarcoplasmic reticulum of rabbit masseter muscle.

Modulation of sarcoplasmic reticulum (SR) Ca(2+) transport by endogenous calmodulin-dependent protein kinase II (CaM K II) involves covalent changes of regulatory protein phospholamban (PLB), as a common, but not the only mechanism, in limb slow-twitch muscles of certain mammalian species, such as the rabbit. Here, using immunofluorescent techniques in situ, and biochemical and immunological methods on the isolated SR, we have demonstrated that rabbit masseter, a muscle with a distinct embryological origin, lacks PLB. Accommodating embryological heterogeneity in the paradigm of neural-dependent expression of specific isogenes in skeletal muscle fibers, our results provide novel evidence for the differential expression in the SR of 72 kDa beta components of CaM K II, together with the expression of a slow-twitch sarcoendoplasmic reticulum Ca(2+)-ATPase isoform, both in limb muscle and in the masseter.

Animals↗
PubMed2000

The effects of nitroxide radicals on oxidative DNA damage.

The indolinonic and quinolinic aromatic nitroxides synthesized by us are a novel class of biological antioxidants, which afford a good degree of protection against free radical-induced oxidation in different lipid and protein systems. To further our understanding of their antioxidant behavior, we thought it essential to have more information on their effects on DNA exposed to free radicals. Here, we report on the results obtained after exposure of plasmid DNA and calf thymus DNA to peroxyl radicals generated by the water-soluble radical initiator, 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), and the protective effects of the aromatic nitroxides and their hydroxylamines, using a simple in vitro assay for DNA damage. In addition, we also tested for the potential of these nitroxides to inhibit hydroxyl radical-mediated DNA damage inflicted by Fenton-type reactions using copper and iron ions. The commercial aliphatic nitroxides 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), and bis(2,2, 6,6-tetramethyl-1-oxyl-piperidin-4-yl)sebacate (TINUVIN 770) were included for comparison. The results show that the majority of compounds tested protect: (i) both plasmid DNA and calf thymus DNA against AAPH-mediated oxidative damage in a concentration-dependent fashion (1-0.1 mM), (ii) both Fe(II) and Cu(I) induced DNA oxidative damage. However, all compounds failed to protect DNA against damage inflicted by the presence of the transition metals in combination with H(2)O(2). The differences in protection between the compounds are discussed in relation to their molecular structure and chemical reactivity.

Amidines↗
PubMed2000

Variation of phospholamban in slow-twitch muscle sarcoplasmic reticulum between mammalian species and a link to the substrate specificity of endogenous Ca(2+)-calmodulin-dependent protein kinase.

Systematic immunological and biochemical studies indicate that the level of expression of sarcoplasmic reticulum (SR) Ca(2+)-ATPase regulatory protein phospholamban (PLB) in mammalian slow-twitch fibers varies from zero, in the rat, to significant levels in the rabbit, and even higher in humans. The lack of PLB expression in the rat, at the mRNA level, is shown to be exclusive to slow-twitch skeletal muscle, and not to be shared by the heart, thus suggesting a tissue-specific, in addition to a species-specific regulation of PLB. A comparison of sucrose density-purified SR of rat and rabbit slow-twitch muscle, with regard to protein compositional and phosphorylation properties, demonstrates that the biodiversity is two-fold, i.e. (a) in PLB membrane density; and (b) in the ability of membrane-bound Ca(2+)-calmodulin (CaM)-dependent protein kinase II to phosphorylate both PLB and SERCA2a (slow-twitch isoform of Ca(2+)-ATPase). The basal phosphorylation state of PLB at Thr-17 in isolated SR vesicles from rabbit slow-twitch muscle, colocalization of CaM K II with PLB and SERCA2a at the same membrane domain, and the divergent subcellular distribution of PKA, taken together, seem to argue for a differential heterogeneity in the regulation of Ca(2+) transport between such muscle and heart muscle.

Animals↗
PubMed2000

Cyto- and genotoxic effects of novel aromatic nitroxide radicals in vitro.

Because of the increasing interest in the use of nitroxide radicals as antioxidants and probes for various applications in biological systems, the question of their toxicity is of paramount importance. Cytotoxicity and mutagenicity studies have been extensively performed with the commercially available aliphatic nitroxides, and the general outcome is that these compounds are nonmutagenic and relatively noncytotoxic. In this study, the cytotoxicity and genotoxicity of a new class of aromatic nitroxides that we have synthesized (i.e., indolinonic and quinolinic nitroxides), whose antioxidant activity has been established in both chemical and biological systems, were evaluated and compared with those of two commercial nitroxides and with that of butylated hydroxytoluene (BHT). The mutagenicity assay was performed using Salmonella typhimurium tester strains TA98, TA100, and TA102, chosen on the basis of their ability to detect various types of mutations and their sensitivity to oxidative damage. None of the compounds tested were found to be mutagenic. The colony-forming assay (CFA) using Chinese hamster ovary (CHO) AS52 cells was employed for determining the cytotoxicity of the test compounds. On comparing the effective dose that inhibits the CFA by 50% (IC(50)), most of the compounds tested on an equal molar concentration basis were less toxic than BHT. Therefore, the overall results obtained correlate well with the data reported in the literature on the toxicity of aliphatic nitroxides and lend support to the possible use of these compounds as therapeutic antioxidants.

Animals↗
PubMed2000

Increased oxidative modification of albumin when illuminated in vitro in the presence of a common sunscreen ingredient: protection by nitroxide radicals.

We previously reported on the ability of dibenzoylmethane (DBM) and a relative, Parsol 1789, used as a ultraviolet A (UVA)-absorbing sunscreen, to generate free radicals upon illumination, and as a consequence, to inflict strand breaks in plasmid DNA in vitro. This study has now been extended to determine the effects of Parsol 1789 and DBM on proteins, under UVA illumination, with the sole purpose of gaining more knowledge on the photobiological effects of sunscreen chemicals. Parsol 1789 (100 microM) caused a 2-fold increase in protein carbonyl formation (an index of oxidative damage) in bovine serum albumin (BSA) when exposed to illumination, and this damage was both concentration- and time-dependent. The degree of protein damage was markedly reduced by the presence of free radical scavengers, namely piperidinic and indolinonic nitroxide radicals, in accordance with our previous study. Vitamin E had no effect under the conditions used. The results obtained corroborate the fact that Parsol 1789 generates free radicals upon illumination and that these are, most probably, responsible for the protein damage observed under the conditions used in our system. However, at present, we cannot extrapolate from these results the relevance to human use of sunscreens; therefore, further studies should be necessary to determine the efficacy at the molecular and cellular level of this UVA-absorber in order to ascertain protection against photocarcinogenic risk.

Animals↗
PubMed2000

Pharmacological clues to calmodulin-mediated activation of skeletal ryanodine receptor using [3H]-ryanodine binding.

The hypothesis that calmodulin (CaM) may act as a positive modulator of junctional SR Ca2+-release channel/ ryanodine receptor (RyRl) rests largerly on the demonstrated capacity of CaM to interact structurally and functionally with RyRl at pCa > 8 (Tripathy et al., 1995). The goal of the present [3H]-ryanodine binding study was to produce, in isolated terminal cisternae (TC) and in purified junctional face membrane (JFM), CaM-mediated activation of RyRl at less extreme pCa values, i.e. closer to resting myoplasmic pCa, and to analyze more accurately the corresponding changes in binding affinity for ryanodine of the receptor. We were able to monitor these changes at an optimum pCa of 6.5, following pre-activation of native RyRl by mM concentrations of caffeine or microM concentrations of antraquinone compound doxorubicin, and at various doses of these triggers. CaM increased the affinity of ryanodine binding to isolated TC in the presence of 1 mM AMP-PCP as an activator of RyRl; the Kd for ryanodine binding was reduced from 21.8 nM to 13.2 nM by 1microM CaM. Similar effects of CaM were seen when AMP-PCP was replaced by either caffeine or doxorubicin. In order to discount the involvement of SR extrajunctional proteins in this effect, the experiments were repeated on purified JFM. Again, CaM increased the affinity of ryanodine binding; the Kd was reduced from 11.1 nM to 7.0 nM by 1 microM CaM (in the presence of doxorubicin). Pharmacological triggers of CaM-activatory action on native RyRl, like caffeine and doxorubicin, have long been characterized for their ability to activate RyRl by increasing the Ca2+-sensitivity of the receptor. We speculate that the triggering effect of these agents on the CaM-mediated mechanism in vitro might mimick one of the early effects of the activation of RyRl in skeletal muscle, during E-C coupling.

Adenosine Triphosphate↗
PubMed1999

Characteristic distribution of HTLV type I and HTLV type II carriers among native ethnic groups in South America.

To confirm the geographic and ethnic segregation of HTLV-I and HTLV-II carriers in native populations in South America, we have conducted a seroepidemiological study of native populations in South America, including HTLV-I carriers distributed among seven ethnic groups in the Andes highlands of Colombia, Peru, Bolivia, Argentina, and Chile, and two ethnic groups on Chiloe Island and Easter Island; and HTLV-II carriers distributed among seven ethnic groups of the lowlands along the Atlantic coast of Colombia, Orinoco, Amazon, and Patagonia, and one ethnic group on Chiloe Island. The incidence rate of HTLV-I and HTLV-II carriers varied among the ethnic groups, ranging from 0.8 to 6.8% for HTLV-I seropositivity and from 1.4 to 57.9% for HTLV-II seropositivity. A new HTLV-I focus was found among the Peruvian Aymara (1.6%), the Bolivian Aymara (5.3%) and Quechua (4.5%), the Argentine Puna (2.3%), and the Chilean Atacama (4.1%), while on HTLV-II focus was found among the Brazilian Kayapo (57.9%), the Paraguayan Chaco (16.4%), and the Chilean Alacalf (34.8%) and Yahgan (9.1%). The distribution of HTLV-I/II foci showed a geographic clustering of HTLV-I foci in the Andes highlands and of HTLV-II foci in the lowlands of South America. It was thus suggested that South American natives might be divided into two major ethnic groups by HTLV-I and HTLV-II carrier state.

Adolescent↗
PubMed1999

Action of quinolinic and indolinonic aminoxyls as radical-scavenging antioxidants.

The kinetic studies on the actions of quinolinic and indolinonic aminoxyls in the oxidation of lipid peroxidation induced by free radicals were carried out to evaluate their antioxidant activity. These aminoxyls showed a similar reactivity toward peroxyl radical with alpha-tocopherol. The antioxidant efficacies of aminoxyls against oxidation of methyl linoleate in homogeneous solution were smaller than that of alpha-tocopherol. Hydroxylamine, a reduced form of aminoxyl, possessed a comparative antioxidant efficacy with alpha-tocopherol and was capable of suppressing the consumption of alpha-tocopherol. Aminoxyls showed more potent antioxidant activity than alpha-tocopherol against the oxidation of methyl linoleate micelles induced by peroxyl radical or by a combination of copper ion and hydrogen peroxide. These results suggest that quinolinic and indolinonic aminoxyls may act as potent antioxidants against lipid peroxidation, especially in the presence of a good reductant which reduces aminoxyl radicals to hydroxylamines.

Antioxidants↗
PubMed1999

Nitroxide radicals protect DNA from damage when illuminated in vitro in the presence of dibenzoylmethane and a common sunscreen ingredient.

Indolinonic nitroxide radicals efficiently scavenge oxygen- and carbon-centered radicals. They protect lipid and protein systems against oxidative stress, but little is known about their capacity to protect DNA against radical-mediated damage. We compare indolinonic nitroxides and the piperidines TEMPO and TEMPOL for their ability to inhibit strand breaks inflicted on DNA when it is illuminated in vitro in the presence of dibenzoylmethane (DBM) and a relative, Parsol 1789, used as a UVA-absorbing sunscreen. We used spin-trapping EPR to examine the formation of radicals and plasmid nicking assays to evaluate DNA strand breakage. The results have a two-fold interest. First, they show that all the nitroxides tested efficiently prevent DNA damage in a dose-dependent fashion. Vitamin E had no effect under the conditions used. Second, they show that carbon-centered radicals are produced on illumination of DBM and its relative and that their formation is probably responsible for the direct strand breaks found when naked DNA is illuminated in vitro in their presence. Additional work on the ability of sunscreens to enter human cells and their response to the light that penetrates sunscreen-protected skin would be necessary before any conclusion could be drawn as to whether the results reported here are relevant to human use of sunscreens.

Antioxidants↗
PubMed1999

Interaction of triadin with histidine-rich Ca(2+)-binding protein at the triadic junction in skeletal muscle fibers.

The present study documents the binding interaction of skeletal muscle sarcoplasmic reticulum (SR) transmembrane protein triadin with peripheral histidine-rich, Ca(2+)-binding protein (HCP). In addition to providing further evidence that HCP coenriches with RyR1, FKBP-12, triadin and calsequestrin (CS) in sucrose-density-purified TC vesicles, using specific polyclonal antibody, we show it to be expressed as a single protein species, both in fast-twitch and slow-twitch fibers, and to identically localize to the I-band. Colocalization of HCP and triadin at junctional triads is supported by the overlapping staining pattern using monoclonal antibodies to triadin. We show a specific binding interaction between digoxigenin-HCP and triadin, using ligand blot techniques. The importance of this finding is strengthened by the similarities in binding affinity and in Ca2+ dependence, (0.1-1 mM Ca2+) of the interaction of digoxigenin-HCP with immobilized TC vesicles. Suggesting that triadin dually interacts with HCP and with CS, at distinct sites, we have found that triadin-CS interaction in overlays does not require the presence of Ca2+. Consistent with the binding of CS to triadin luminal domain (Guo and Campbell, 1995), we show that binding sites for digoxigenin-CS, although not binding sites for digoxigenin-HCP, can be recovered in the 92 kDa triadin fragment, after chymotryptic cleavage of the NH2-terminal end of the folded molecule in intact TC vesicles. These differential effects form the basis for the hypothesis that HCP anchors to the junctional membrane domain of the SR, through binding to triadin short cytoplasmic domain at the NH2 terminus. Although the function of this interaction, as such, is not well understood, it seems of potential biological interest within the more general context of the structural-functional role of triadin at the triadic junction in skeletal muscle.

Animals↗
PubMed1999

Sarcoplasmic reticulum in aged skeletal muscle.

A decrease in muscle mass and strength and a slowing of muscle contraction are common features of the ageing process. Recent advances in basic biochemical knowledge have provided new insights into pathogenetic mechanisms underlying age-related changes in the excitation-contraction coupling process, Ca2+-transients and isometric twitch-contraction time. Sarcoplasmic reticulum (SR) Ca2+-pumps are not basically altered in physiological ageing, but several aspects of the Ca2+-transport system remain controversial, regarding phosphorylation-dependent regulation in slow-twitch muscles, in particular. It seems that conflicting reports and divergent interpretations concerning the effect of ageing on SR Ca2+-release arise from the type of muscle, the stage of the ageing process and the animal species. A cause-effect relationship between the decrease in dihydropyridine receptors and in muscle strength is strongly suggested by studies in transgenic mice, but is unsupported by our studies with fast-twitch and slow-twitch muscles of old rats. Our experimental evidence also seems to exclude the occurrence of age-related changes in the number and in the functional behaviour of Ca2+-release channels/ryanodine receptors (RyR1), based on ¿3H-ryanodine binding studies. There is emerging, although only suggestive evidence, so far, that modulation of RyR1 by SR luminal protein calsequestrin, or the functional coupling of RyRs by FKBP-12, may be altered in ageing skeletal muscle.

Aging↗
PubMed1999

Reactivity of an indolinonic aminoxyl with superoxide anion and hydroxyl radicals.

The increasing knowledge on the participation of free radicals in many diverse clinical and pathological conditions, has consequently expanded the search for new and versatile antioxidants aimed at combating oxidative stress. Our interest in this field concerns aromatic indolinonic aminoxyls (nitroxides) which efficiently react with alkoxyl, peroxyl, aminyl, arylthiyl and alkyl radicals to give non-paramagnetic species. This prompted us to test their antioxidant activity on different biological systems exposed to free radical-induced oxidative stress and the results obtained so far have been very promising. However little is known about their behaviour towards superoxide and hydroxyl radicals. Here, we report on the reactivity of an indolinonic aminoxyl, with the two above mentioned radicals using hypoxanthine/xanthine oxidase and potassium superoxide for generating the former and the Fenton reagent for the latter. Besides performing the deoxyribose assay for studying the reaction of the aminoxyl with hydroxyl radical and monitoring spectral changes of the aminoxyl in the presence of superoxide radical, macroscale reactions were performed in both cases and the products of the reactions isolated and identified. The EPR technique was used in this study to help elucidate the data obtained. The results show that this compound efficiently reacts with both hydroxyl and superoxide radicals and furthermore, it is capable of maintaining iron ions in its oxidized form. The results thus contribute to increasing the knowledge on the reactivity of indolinonic aminoxyls towards free radical species and as a consequence, these compounds and/or other aminoxyl derivatives, may be considered as complementary, and sometimes alternative sources for combating oxidative damage.

Cyclic N-Oxides↗