Publications

Abstract Tumour associated carbonic anhydrases (CAs) IX and XII have been recognised as potential targets for the treatment of hypoxic tumours. Therefore, considering the high pharmacological potential of the chromene scaffold as selective ligand of the IX and XII isoforms, two libraries of compounds, namely 2H-chromene and 7H-furo-chromene derivatives, with diverse substitution patterns were designed and synthesised. The structure of the newly synthesised compounds was characterised and their inhibitory potency and selectivity towards human CA off target isoforms I, II and cancer-associated CA isoforms IX and XII were evaluated. Most of the compounds inhibit CA isoforms IX and XII with no activity against the I and II isozymes. Thus, while the potency was influenced by the substitution pattern along the chromene scaffold, the selectivity was conserved along the series, confirming the high potential of both 2H-chromene and 7H-furo-chromene scaffolds for the design of isozyme selective inhibitors. [GRAPHICS]

Abstract Throughout their life cycle, plants are subjected to a variety of environmental constraints, including abiotic stresses. The present study aimed at characterizing the responses of the two tomato cultivars Gold Nugget (GN) and Purple Calabash (PC) exposed to a combination of nickel (Ni) and drought. The following hypotheses were pursued: (i) the activation of responses to one stressor eases further adjustments to a second stressor; and (ii) the two tomato cultivars are differentially susceptible to drought and heavy metal-stress. Besides biometrical evaluations, the distribution of Ni in tissues and the redox homeostasis in both cultivars were compared in response to Ni-stress, polyethylene glycol (PEG)-induced drought, and to their combination. Regarding single stresses, Ni caused more harmful effects to plants than PEG-induced drought, in terms of growth inhibition and production of reactive oxygen species. Ni was mostly accumulated in the roots. The GN cultivar promptly activated antioxidant defenses under Ni-stress, while, in PC, such antioxidants were more strongly induced under combined stress. Stress co-exposure led to a drastic proline accumulation, resembling a signal of stress sensitivity. Overall, the GN cultivar seemed to be less susceptible to the combined stress than PC, as it could activate stronger antioxidant defenses under single Ni toxicity, possibly easing further adjustments demanded by the later co-exposure to drought. This study showed that the two cultivars of the same species had different levels of perception and responsiveness to Ni-induced stress, which translated into different susceptibilities to the combined exposure to PEG-induced drought. [GRAPHICS] .

Abstract Propargylamine is a chemical moiety whose properties have made it a widely distributed group within the fields of medicinal chemistry and chemical biology. Its particular reactivity has traditionally popularized the preparation of propargylamine derivatives using a large variety of synthetic strategies, which have facilitated the access to these compounds for the study of their biomedical potential. This review comprehensively covers and analyzes the applications that propargylamine-based derivatives have achieved in the drug discovery field, both from a medicinal chemistry perspective and from a chemical biology-oriented approach. The principal therapeutic fields where propargylamine-based compounds have made an impact are identified, and a discussion of their influence and growing potential is included. Tweetable abstractPropargylamine derivatives are commonly present in various areas of #drugdiscovery. In this new @fsgfmc review article, scientists @aitorcarneiro and @mariacmatos from @UPorto and @UniversidadeUSC discuss the reasons underlying recent uses and applications of these compounds.

Abstract Like the well-known sulfa drugs, Sulfonamides are ascribed to a myriad of biological activities, including antioxidant activity. In fact, several tertiary sulfonamides, particularly N, N-disubstituted analogues, are recognized as antioxidants that can prevent or minimize oxidative damage associated with several oxidative-stress-related diseases. The structural diversity of this class of compounds paved the way for drug discovery programs aimed at finding therapeutic agents. Attributes such as low-cost synthetic procedures, easy accessibility of reagents, and a broad spectrum of biological activities made sulfonamides and derivatives excellent candidates for synthesizing chemical libraries with structural diversity. Sulfonamide-based drugs are most of the sulfur-containing drugs approved by the United States Food and Drug Administration (FDA). Although sulfonamide derivatives have been extensively exploited as antibacterial agents, their therapeutic potential as antioxidants is relatively underexplored despite the prevalence of oxidative stress-mediated diseases and the urgent need for new and more effective antioxidant drugs. Some sulfonamide derivatives were shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2), the main regulator of the endogenous antioxidant response, a critical process used by cells in response to oxidative stress. The antioxidant role of sulfonamides and derivatives as Nrf2 activators is also reviewed. The antioxidant mechanism of action of sulfonamides has not been fully clarified, but as they have antioxidant properties, it is a subject worthy of in-depth study. The present review is focused on sulfonamides and derivatives as potential antioxidants along the period 2013-2021 and intends to stimulate research in the area.

Abstract Ferroptosis is a type of regulated cell death characterized by intracellular accumulation of iron and reactive oxy-gen species, inhibition of system Xc-, glutathione depletion, nicotinamide adenine dinucleotide phosphate oxida-tion and lipid peroxidation. Since its discovery and characterization in 2012, many efforts have been made to reveal the underlying mechanisms, modulating compounds, and its involvement in disease pathways.Ferroptosis inducers include erastin, sorafenib, sulfasalazine and glutamate, which, by inhibiting system Xc-, pre-vent the import of cysteine into the cells. RSL3, statins, Ml162 and Ml210 induce ferroptosis by inhibiting gluta-thione peroxidase 4 (GPX4), which is responsible for preventing the formation of lipid peroxides, and FIN56 and withaferin trigger GPX4 degradation. On the other side, ferroptosis inhibitors include ferrostatin-1, liproxstatin-1, alpha-tocopherol, zileuton, FSP1, CoQ10 and BH4, which interrupt the lipid peroxidation cascade. Additionally, deferoxamine, deferiprone and N-acetylcysteine, by targeting other cellular pathways, have also been classified as ferroptosis inhibitors.Increased evidence has established the involvement of ferroptosis in distinct brain diseases, including Alzheimer's, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis, multiple sclerosis, and Friedreich's ataxia. Thus, a deep understanding of how ferroptosis contributes to these diseases, and how it can be modulated, can open a new window of opportunities for novel therapeutic strategies and targets. Other stud-ies have shown a sensitivity of cancer cells with mutated RAS to ferroptosis induction and that chemotherapeutic agents and ferroptosis inducers synergize in tumor treatment. Thus, it is tempting to consider that ferroptosis may arise as a target mechanistic pathway for the treatment of brain tumors.Therefore, this work provides an up-to-date review on the molecular and cellular mechanisms of ferroptosis and their involvement in brain diseases. In addition, information on the main ferroptosis inducers and inhibitors and their molecular targets is also provided.(c) 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Abstract Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of upper and lower motor neurons (MNs) leading to paralysis and, ultimately, death by respiratory failure 3-5 years after diagnosis. Edaravone and Riluzole, the only drugs currently approved for ALS treatment, only provide mild symptomatic relief to patients. Extraordinary progress in understanding the biology of ALS provided new grounds for drug discovery. Over the last two decades, mitochondria and oxidative stress (OS), iron metabolism and ferroptosis, and the major reg-ulators of hypoxia and inflammation - HIF and NF-kappa B - emerged as promising targets for ALS therapeutic intervention. In this review, we focused our attention on these targets to outline and discuss current advances in ALS drug development. Based on the challenges and the roadblocks, we believe that the rational design of multi -target ligands able to modulate the complex network of events behind the disease can provide effective therapies in a foreseeable future.

Abstract Psychiatric and neurological disorders affect millions of people worldwide. Currently available treatments may help to improve symptoms, but they cannot cure the diseases. Therefore, there is an urgent need for potent and safe therapeutic solutions. 8-Amide and 8-carbamatecoumarins were synthetized and evaluated as human monoamine oxidase A and B (hMAO-A and hMAO-B) inhibitors. Comparison between both scaffolds has been established, and we hypothesized that the introduction of different substituents can modulate hMAO activity and selectivity. N-(7-Hydroxy-4-methylcoumarin-8-yl)-4-methylbenzamide (9) and ethyl N-(7-hydroxy-4-methylcoumarin-8-yl)carbamate (20) proved to be the most active and selective hMAO-A inhibitors (IC50 = 15.0 nM and IC50 = 22.0 nM, respectively), being compound 9 an irreversible hMAO-A inhibitor twenty-four times more active in vitro than moclobemide, a drug used in the treatment of depression and anxiety. Based on PAMPA assay results, both compounds proved to be good candidates to cross the blood-brain barrier. In addition, these compounds showed non-significant cytotoxicity on neuronal viability assays. Also, the best compound proved to have a t1/2 of 6.84 min, an intrinsic clearance of 195.63 mu L min-1 mg-1 protein, and to be chemically stable at pH 3.0, 7.4 and 10.0. Docking studies were performed to better understand the binding affinities and selectivity profiles for both hMAO isoforms. Finally, theoretical drug-like properties calculations corroborate the potential of both scaffolds on the search for new therapeutic solutions for psychiatric disorders as depression.

Abstract Simple Summary Non-alcoholic fatty liver disease (NAFLD) is a global pandemic that affects 25% of the world's population and represents a serious health and economic concern worldwide resulting from unhealthy dietary habits combined with a sedentary lifestyle, although genetic contributions have been documented. Although the molecular mechanisms that cause the progression are not fully understood, metabolic-dysfunction-associated fatty liver disease is strong evidence that mitochondrial dysfunction plays a significant role in NAFLD. This review postulates that the regulation of hepatocytes' mitochondrial physiology to maintain hepatic mitochondrial mass, integrity, and function are differently altered during NAFLD progression. This review summarizes evidence linking mitochondrial (dys)function with NAFLD pathophysiology, discriminating it in different disease stages (simple steatosis, steatohepatitis, liver fibrosis, cirrhosis, and hepatocellular carcinoma). As mitochondrial dysfunction is considered a driving force in NAFLD progression, targeting hepatocytes' mitochondrial physiology could contribute to establishing an effective therapy for NAFLD. However, additional studies on distinct mitochondrial sub-populations roles in NAFLD, the impact of mitochondrial (mis)communication with other subcellular organelles (peroxisomes and lipid droplets), the impact of negligible pathways, such as fatty acid oxidation, de novo lipogenesis, and the pentose phosphate pathway in the hepatocytes' mitochondrial physiology in different stages of NAFLD are topics to explore. Non-alcoholic fatty liver disease (NAFLD) is a global pandemic affecting 25% of the world's population and is a serious health and economic concern worldwide. NAFLD is mainly the result of unhealthy dietary habits combined with sedentary lifestyle, although some genetic contributions to NAFLD have been documented. NAFLD is characterized by the excessive accumulation of triglycerides (TGs) in hepatocytes and encompasses a spectrum of chronic liver abnormalities, ranging from simple steatosis (NAFL) to steatohepatitis (NASH), significant liver fibrosis, cirrhosis, and hepatocellular carcinoma. Although the molecular mechanisms that cause the progression of steatosis to severe liver damage are not fully understood, metabolic-dysfunction-associated fatty liver disease is strong evidence that mitochondrial dysfunction plays a significant role in the development and progression of NAFLD. Mitochondria are highly dynamic organelles that undergo functional and structural adaptations to meet the metabolic requirements of the cell. Alterations in nutrient availability or cellular energy needs can modify mitochondria formation through biogenesis or the opposite processes of fission and fusion and fragmentation. In NAFL, simple steatosis can be seen as an adaptive response to storing lipotoxic free fatty acids (FFAs) as inert TGs due to chronic perturbation in lipid metabolism and lipotoxic insults. However, when liver hepatocytes' adaptive mechanisms are overburdened, lipotoxicity occurs, contributing to reactive oxygen species (ROS) formation, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress. Impaired mitochondrial fatty acid oxidation, reduction in mitochondrial quality, and disrupted mitochondrial function are associated with a decrease in the energy levels and impaired redox balance and negatively affect mitochondria hepatocyte tolerance towards damaging hits. However, the sequence of events underlying mitochondrial failure from steatosis to hepatocarcinoma is still yet to be fully clarified. This review provides an overview of our understanding of mitochondrial adaptation in initial NAFLD stages and highlights how hepatic mitochondrial dysfunction and heterogeneity contribute to disease pathophysiology progression, from steatosis to hepatocellular carcinoma. Improving our understanding of different aspects of hepatocytes' mitochondrial physiology in the context of disease development and progression is crucial to improving diagnosis, management, and therapy of NAFLD/NASH.

Abstract Ferroptosis is a type of regulated cell death promoted by the appearance of oxidative perturbations in the intracellular microenvironment constitutively controlled by glutathione peroxidase 4 (GPX4). It is characterized by increased production of reactive oxygen species, intracellular iron accumulation, lipid peroxidation, inhibition of system Xc-, glutathione depletion, and decreased GPX4 activity. Several pieces of evidence support the involvement of ferroptosis in distinct neurodegenerative diseases. In vitro and in vivo models allow a reliable transition to clinical studies. Several in vitro models, including differentiated SH-SY5Y and PC12 cells, among others, have been used to investigate the pathophysiological mechanisms of distinct neurodegenerative diseases, including ferroptosis. In addition, they can be useful in the development of potential ferroptosis inhibitors that can be used as disease-modifying drugs for the treatment of such diseases. On the other hand, in vivo models based on the manipulation of rodents and invertebrate animals, such as Drosophila melanogaster, Caenorhabditis elegans, and zebrafish, have been increasingly used for research in neurodegeneration. This work provides an up-to-date review of the main in vitro and in vivo models that can be used to evaluate ferroptosis in the most prevalent neurodegenerative diseases, and to explore potential new drug targets and novel drug candidates for effective disease-modifying therapies.

Abstract Mescaline derivative (2C phenethylamines) drugs have been modified by the introduction of a N-2-methoxybenzyl group to originate a new series of compounds with recognized and potent psychedelic effects, the NBOMe-drugs. Although they are prevalent in unregulated drug markets, their toxicity profile is still poorly understood, despite several reports highlighting cases of acute intoxication, with brain and liver toxicity. Thus, in this study, mescaline, 2C-N (insertion of a nitro in the para position of the 2C phenethylamines aromatic ring) and 2C-B (insertion of a bromide in the para position of the 2C phenethylamines aromatic ring) and their corresponding NBOMe counterparts, mescaline-NBOMe, 25N-NBOMe and 25B-NBOMe, were synthetized and the in vitro neuro- and hepatocytotoxicity evaluated in differentiated SH-SY5Y and HepG2 cell lines, respectively. Cytotoxicity, oxidative stress, metabolic and energetic studies were performed to evaluate the main pathways involved in their toxicity. Our results demonstrated that the presence of the N-2-methoxybenzyl group significantly increased the in vitro cytotoxicity of 2C phenethylamines drugs in both cell lines, with the NBOMe drugs presenting lower EC50 values when compared to their counterparts. Consistently, our data showed a correlation between the drug's lipophilicity and the EC50 values, except for 2C-B. The 2C-B presented higher cytotoxic effects in both cell lines than mescaline-NBOMe, a result that can be explained by its higher passive permeability. All the NBOMe derivatives were able to cross the blood-brain barrier. Considering metabolic studies, the cytotoxicity of these drugs was shown to be influenced by inhibition of cytochrome P450 (CYP), which suggests a potential role of this enzyme complex, especially CYP3A4 and CYP2D6 isoenzymes in SH-SY5Y cells, in their detoxification or bioactivation. Furthermore, in differentiated SH-SY5Y cells, the drugs were able to induce mitochondrial membrane depolarization, and to disrupt GSH and ATP intracellular levels, these effects being concentration dependent and more pronounced for the NBOMe derivatives. No ROS overproduction was detected for any of the drugs in the tested experimental conditions. A correlation between a drug's lipophilicity and the EC50 values in both cell lines, except for 2C-B, was also obtained. In summary, the introduction of a NBOMe moiety to the parent drugs significantly increases their lipophilicity, brain permeability and cytotoxic effects, with GSH and ATP homeostasis disruption. The inhibition of CYP3A4 and CYP2D6 emphasized that CYP-mediated metabolism impacts the toxicity of these drugs.