Alzheimer’s disease (AD) is a neurodegenerative disease that is usually accompanied by aging, increasingly being the most common cause of dementia in the elderly. This disorder is characterized by the accumulation of beta amyloid plaques (Aβ) resulting from impaired amyloid precursor protein (APP) metabolism, together with the formation of neurofibrillary tangles and tau protein hyperphosphorylation. The exacerbated production of reactive oxygen species (ROS) triggers the process called oxidative stress, which increases neuronal cell abnormalities, most often followed by apoptosis, leading to cognitive dysfunction and dementia. In this context, the development of new therapies for the AD treatment is necessary. Antioxidants, for instance, are promising species for prevention and treatment because they are capable of disrupting the radical chain reaction, reducing the production of ROS. These species have also proven to be adjunctive to conventional treatments making them more effective. In this sense, several recently published works have focused their attention on oxidative stress and antioxidant species. Therefore, this review seeks to show the most relevant findings of these studies.

Mycobacterium tuberculosis (Mt) is a leading cause of infectious disease in the world today. This outlook is aggravated by a growing number of Mt infections in individuals who are immunocompromised as a result of HIV infections. Thus, new and more potent anti-tuberculosis agents are necessary. Therefore, DNA gyrase was selected as a target enzyme to combat Mt. In this work, the first three-dimensional molecular model of the hypothetical structures for the Mycobacterium tuberculosis DNA gyrase (mtDNAg) was elucidated by a homology modeling method. In addition, the orientations and binding affinities of some gatifloxacin analogs with those new structures were investigated. Our findings could be helpful for the design of new more potent gatifloxacin analogs.

There are major differences between the structures of human dihydrofolate reductase (hD-HFR) and Mycobacterium tuberculosis dihydrofolate reductase (mtDHFR). These differences may allow the design of more selective mtDHFR inhibitors. In this paper, we have used docking approaches to study the binding orientations and predict binding affinities of 2,4-diamino-5-methyl-5-deazapteridines derivatives in both hDHFR and mtDHFR. Our results of molecular docking combined with experimental data for inhibition of the human and mycobacterial dihydrofolate reductases suggest the presence of empty spaces around the 2,4-diaminodeazapteridine and N¹⁰-phenyl rings in the mtDHFR active site that are not found in the hDHFR-bound structures. Preparation of new analogs with substituents attached to C7 of the pteridine nucleus and positions 3 and 4 of the N¹⁰-phenyl group should increase the affinity and selectivity for mtDHFR.

Acetylcholinesterase (AChE) is the key enzyme responsible for deactivating the ACh neurotransmitter. Irreversible or prolonged inhibition of AChE, therefore, elevates synaptic ACh leading to serious central and peripheral adverse effects which fall under the cholinergic syndrome spectra. To combat the toxic effects of some AChEI, such as organophosphorus (OP) nerve agents, many compounds with reactivator effects have been developed. Within the most outstanding reactivators, the substances denominated oximes stand out, showing good performance for reactivating AChE and restoring the normal synaptic acetylcholine (ACh) levels. This review was developed with the purpose of covering the new advances in AChE reactivation. Over the past years, researchers worldwide have made efforts to identify and develop novel active molecules. These researches have been moving farther into the search for novel agents that possess better effectiveness of reactivation and broad-spectrum reactivation against diverse OP agents. In addition, the discovery of ways to restore AChE in the aged form is also of great importance. This review will allow us to evaluate the major advances made in the discovery of new acetylcholinesterase reactivators by reviewing all patents published between 2016 and 2019. This is an important step in continuing this remarkable research so that new studies can begin.

Theδ-FeOOH/PMMA nanocomposites with 0.5 and 2.5 wt.% ofδ-FeOOH were prepared by grafting 3-(trimethoxysilyl)propyl methacrylate on the surface of the iron oxyhydroxide particles. The FTIR spectra of theδ-FeOOH/PMMA nanocomposites showed that the silane monomers were covalently attached to theδ-FeOOH particles. Because of the strong interaction between the PMMA andδ-FeOOH nanoparticles, the thermal stability of theδ-FeOOH/PMMA nanocomposites was improved compared to the pure PMMA. The SEM analysis conferred the size agglomerate of particles regarding the morphology of samples. The theoretical study enabled a better understanding of the interaction of the polymer with the iron oxyhydroxide. The DFT-based calculations reinforce the radical trapping mechanism of stabilization of nanocomposites; that is, Fe³⁺species might be able to accept electrons coming from the organic phase that decomposes via radical unzipping. The radical scavenge effect delays the weight loss of polymer.