Daniela Ramos Truzzi

• B.S., M.S., Ph.D.
• Professor (Assistant) at University of São Paulo

Peroxymonocarbonate (HCO4–/HOOCO2–) is produced by the reversible reaction of CO2/HCO3– with H2O2 (K = 0.33 M–1, pH 7.0). Although produced in low yields at physiological pHs and H2O2 and CO2/HCO3– concentrations, HCO4– oxidizes most nucleophiles with rate constants 10 to 100 times higher than those of H2O2. Boronate probes are known examples becau...

Cancer is a severe disease that causes a significant number of deaths worldwide every year. Treatments have been available, such as cisplatin, to help combat this disease. However, recent studies have shown that the enzyme system glutathione/glutathione S-transferases (GSH/GST) can cause resistance of tumor cells to this type of cancer treatment. F...

DNIC can be formed in aqueous media in the absence of thiols via mechanisms that depend exclusively on Fe(II) and NO. However, these reactions do not take place at intracellular...

Copper nitrite reductase mimetics were synthesized using three new tridentate ligands sharing the same N,N,N motif of coordination. The ligands were based on L-proline modifications, attaching a pyridine and a triazole to the pyrrolidine ring, and differ by a pendant group (R = phenyl, n-butyl and n-propan-1-ol). All complexes coordinate nitrite, a...

Cancer is a global public health issue. Neuroblastoma (NB) originates from any tissue of the sympathetic nervous system, and the most affected site is the abdomen. The adrenal gland is the primary site in 38% of cases. Approximately 50% of patients have metastatic disease at diagnosis, and bone marrow is often affected. Metastatic disease is charac...

High carbon dioxide tensions (hypercapnia) are toxic to mammals by both pH-dependent and pH-independent mechanisms that remain partially understood. Relevantly, carbon dioxide reacts with biologically ubiquitous oxygen metabolites such as peroxynitrite and hydrogen peroxide to produce carbonate radical and peroxymonocarbonate, respectively. These m...

Protein S-nitrosation is an important consequence of NO●·metabolism with implications in physiology and pathology. The mechanisms responsible for S-nitrosation in vivo remain debatable and kinetic data on protein S-nitrosation by different agents are limited. 2-Cys peroxiredoxins, in particular Prx1 and Prx2, were detected as being S-nitrosated in...

Dinitrosyl iron complexes (DNICs) are ubiquitous in mammalian cells and tissues producing nitric oxide (NO) and have been argued to play key physiological and pathological roles. Nonetheless, the mechanism and dynamics of DNIC formation in aqueous media remain only partially understood. Here, we report a stopped-flow kinetics and density functional...

2-Cys peroxiredoxins (Prxs) rapidly reduce H2O2, thereby acting as antioxidants and also sensors and transmitters of H2O2 signals in cells. Interestingly, eukaryotic 2-Cys Prxs lose their peroxidase activity at high H2O2 levels. Under these conditions, H2O2 oxidizes the sulfenic acid derivative of the Prx peroxidatic Cys (CPSOH) to the sulfinate (C...

Thiyl radicals are detected by EPR as co-products of dinitrosyl iron complex (DNIC) formation. In demonstrating that DNIC formation generates RS• in a NO rich environment, these results provide a...

The ubiquitous cellular labile iron pool (LIP) is often associated with the production of the highly reactive species hydroxyl radical, which forms through redox reaction with hydrogen peroxide. Several studies indicate that LIP‐dependent hydroxyl radical production causes cellular damage through oxidation of biomolecules. Although LIP's interactio...

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or profes...

Peroxiredoxins (Prx) are abundant thiol peroxidases that react rapidly with H2O2, constituting an important antioxidant defense and acting as sensors and transmitters of H2O2 signals in cells. Certain Prxs are readily inactivated by H2O2 at submillimolar concentrations, whereas others are less sensitive. This oxidative inactivation, or hyperoxidati...

The ubiquitous cellular labile iron pool (LIP) is often associated with the production of the highly reactive hydroxyl radical, which forms through a redox reaction with hydrogen peroxide. Peroxynitrite is a biologically relevant peroxide produced by the recombination of nitric oxide and superoxide. It is a strong oxidant that may be involved in mu...

Protein disulfide isomerase (PDI) is a ubiquitous dithiol-disulfide oxidoreductase that performs an array of cellular functions, such as cellular signaling and responses to cell damaging events. PDI can become dysfunctional by post-translational modifications, including those promoted by biological oxidants, and its dysfunction has been associated...

Pseudomonas aeruginosa is a pathogen that needs to cope with the oxidative insult imposed by the mammalian host. Organic Hydroperoxide Resistance protein (Ohr) is a Cys-based peroxidase that together with its transcriptional regulator Organic Hydroperoxide Resistance Regulator (OhrR) comprises a system that is central to the P. aeruginosa response...

Urate hydroperoxide is a product of the oxidation of uric acid by inflammatory heme-peroxidases. The formation of urate hydroperoxide might be a key event in vascular inflammation, where there is plenty amount of uric acid and inflammatory peroxidases. Urate hydroperoxide oxidizes glutathione and sulfur-containing amino acids and is expected to rea...

Here, we report the synthesis, characterization, crystal data and DFT calculation of a new water-soluble ruthenium(II) carbonyl complex. The trans-[Ru(CO)(NH3)4P(O)(OH)2]Cl is a robust complex in aqueous media. The pKa of 3.3 for the phosphorous acid ligand in this complex was measured by infrared spectroscopy. The trans-[Ru(CO)(NH3)4P(O)(OH)2]⁺ ex...

Protein S-nitrosation is a reversible post-translational modification that has been associated with a variety of physiological and pathophysiological processes. The mechanisms responsible for S - nitrosation in vivo , however, remain debatable. Dinitrosyl iron complexes (DNIC), which are consistently detected in cell and tissues overproducing nitri...

This work evaluated the analgesic and anti-inflammatory activity of the ruthenium(II) complexes trans-[Ru(NO+)(NH3)4(L)](BF4)3 and [Ru(NH3)5(L)](BF4)3 containing the nonsteroidal anti-inflammatory drugs nicotinic acid (Hnic) and its isomer isonicotinic acid (ina) as ligands (L). The antinociceptive potential of these complexes and the free ligands...

A estabilidade do ligante dietil fosfito foi analisada por 1H RMN em solução pH 1,0 e 3,0 a 25°C na presença e na ausência do íon [RuII(H2O)(NH3)5]2+. A hidrólise do dietil fosfito livre não foi observada em pH 3,0, enquanto na presença do íon [RuII(H2O)(NH3)5]2+, neste mesmo pH, esta reação foi observada (kobs=1,0.10-4 s-1). Em solução pH 1,0 a hi...

Ruthenium compounds of the type trans-[Ru(NO)(NH3)4(L)]X3, L = N-heterocyclic ligands, P(OEt)3, SO32–, X = BF4– or PF6–, or [Ru(NO)Hedta], were tested for antitumour activity in vitro against murine melanoma and human tumour cells. The ruthenium complexes induced DNA fragmentation and morphological alterations suggestive of necrotic tumour cell dea...

The trans-[Ru(NO)(NH(3))(4)(P(OH)(3))]Cl(3) complex was synthesized by reacting [Ru(H(2)O)(NH(3))(5)](2+) with H(3)PO(3) and characterized by spectroscopic ((31)P-NMR, δ = 68 ppm) and spectrophotometric techniques (λ = 525 nm, ε = 20 L mol(-1) cm(-1); λ = 319 nm, ε = 773 L mol(-1) cm(-1); λ = 241 nm, ε = 1385 L mol(-1) cm(-1); ν(NO(+)) = 1879 cm(-1...

Nitric oxide plays an important role in various biological processes, such as neurotransmission, blood pressure control, immunological responses, and antioxidant action. The control of its local concentration, which is crucial for obtaining the desired effect, can be achieved with exogenous NO-carriers. Coordination compounds, in particular rutheni...