Annia Galano

Metropolitan Autonomous University | UAM · Departamento de Química

Quinoline represents a promising scaffold for developing potential drugs because of the wide range of biological and pharmacological activities that it exhibits. In the present study, quinoline derivatives obtained from CADMA‐Chem docking protocol were investigated in the mean of molecular dynamics simulations as potential inhibitors of acetylcholi...

Quinoline has been proposed as a privileged molecular framework in medicinal chemistry. Although by itself it has very few applications, its derivatives have diverse biological activities. In this work, 8536 quinoline derivatives, strategically designed using the CADMA-Chem protocol, are presented. This large chemical space was sampled, analyzed an...

Coffee is not only a delicious beverage but also an important dietary source of natural antioxidants. We live in an oxidative world where it is impossible to avoid pollution, stress, food additives, radiation, and other sources of oxidants that eventually lead to severe health disorders. Fortunately, there are chemicals in our diet that counteract...

Coffee is not only a delicious beverage but also an important dietary source of natural antioxidants. We live in an oxidative world where it is impossible to avoid pollution, stress, food additives, radiation, and other sources of oxidants that eventually lead to severe health disorders. Fortunately, there are chemicals in our diet that counteract...

Ferulic acid has numerous beneficial effects on human health, which are frequently attributed to its antioxidant behavior. In this report, many of them are reviewed, and 185 new ferulic acid derivatives are computationally designed using the CADMA-Chem protocol. Consequently, their chemical space was sampled and evaluated. To that purpose, selectio...

Ferulic acid has numerous beneficial effects for human health, which are frequently attributed to its antioxidant behavior. In this report many of them are reviewed and 185 new ferulic acid derivatives are computationally designed, using the CADMA-Chem protocol. For the later, the chemical space was sampled and evaluated. To that purpose selection...

The reactions of limonene with various free radicals (•OCH3, •OBr, •SH, •OOH, and •OOCH3) were investigated along the 273.15–312.15 K temperature range. To that purpose the density functional theory was used, at the M06‐2X/6–311+g(d,p) level. Two reaction mechanisms, hydrogen atom transfer (HAT) and radical adduct formation (RAF) were considered. I...

A computational protocol aimed to design new antioxidants with versatile behavior is presented. It is called Computer-Assisted Design of Multifunctional Antioxidants and is based on chemical properties (CADMA-Chem). The desired multi-functionality consists of in different methods of antioxidant protection combined with neuroprotection, although the...

A systematic, rational search for chalcone derivatives with multifunctional behavior has been carried out, with the support of a computer-assisted protocol (CADMA-Chem). A total of 568 derivatives were constructed by incorporating functional groups into the chalcone structure. Selection scores were calculated from ADME properties, toxicity, and man...

A set of new rasagiline derivatives is presented. They were designed to be antioxidant compounds with the potential to be used for treating neurodegenerative disorders. They are expected to be multifunctional molecules that can help reduce oxidative stress, which is thought to contribute to neurodegenerative disorders. The CADMA‐Chem computational...

Catechol-O-methyltransferase (COMT) degrades catecholamine neurotransmitters, including dopamine. Thus, COMT inhibitors are of potential use in the treatment of neurodegenerative disorders associated with dopamine depletion, such as Parkinson’s disease. In this work, we explored the molecular recognition between the soluble form of human COMT (S-CO...

The purpose of this paper was to determine the inclusion constant of the complex formed between mangiferin and β-cyclodextrin (βCD) at pH 3.4, by Higuchi–Connors and absorption and fluorescence spectroscopies methods, as well as to elucidate whether mangiferin molecule enters to the cavity of βCD by the glucosidic or by the xanthone end of the mole...

A set of new rasagiline derivatives is presented. They were designed to be antioxidant compounds with the potential to be used for treating neurodegenerative disorders. They are expected to be multifunctional molecules that can help reduce oxidative stress, which is thought to contribute to neurodegenerative disorders. The CADMA-Chem computational...

Nopal (Opuntia ficus indica) belonging to the Cactacea family has many nutritional benefits attributed to a wide variety of phenolic and flavonoid compounds. Coumaric acid (COA), ferulic acid (FLA), protocatechuic acid (PRA), and gallic acid (GAA) are the phenolic acids (PhAs) present in nopal. In this study, the role of these PhAs in copper-induce...

Although melatonin is an astonishing molecule, it is possible that chemistry will help in the discovery of new compounds derived from it that may exceed our expectations regarding antioxidant protection and perhaps even neuroprotection. This review briefly summarizes the significant amount of data gathered to date regarding the multiple health bene...

Chemical compounds with antioxidant behavior are recognized as efficient protectors against the harmful effects of reactive oxygen species (ROS) and other chemicals overproduced due to oxidative stress (OS). Sesamol has...

p-Coumaric acid is a ubiquitous molecule, widely distributed in the vegetal kingdom and often found in the human diet. A systematic, rational search for new p-coumaric acid derivatives was performed...

Oxidative conditions are frequently enhanced by the presence of redox metal ions. In this study, the role of capsaicin (8-methyl-N-vanillyl-6-nonenamide, CAP) in copper-induced oxidative stress was investigated using density functional theory simulations. It was found that CAP has the capability to chelate Cu(II), leading to complexes that are hard...

The antioxidant activity of five melatonin derivatives, recently designed, was investigated using the density functional theory. Different mechanisms and reaction sites were considered, as well as the polarity of the environment and the pH in aqueous solution. These melatonin analogs are predicted to be, in both media, more potent peroxyl radical s...

The chalcogens effects on the scavenging power of chrysin, quercetin antioxidants against the peroxyl radical have been investigated in lipid and aqueous solutions, using the density functional theory. Different mechanisms and reaction sites were considered as well as the different acid-base species in aqueous solutions. It was found that the polar...

Density functional theory was employed to highlight the antioxidant working mechanism of higenamine in aqueous and lipid-like environments. Different reaction mechanisms were considered for the reaction of higenamine with the •OOH radical. The pH values and the molar fraction at physiological pH were determined in aqueous solution. The results show...

Oxidative stress has been recognized to play an important role in several diseases, such as Parkinson’s and Alzheimer’s disease, which justifies the beneficial effects of antioxidants in ameliorating the deleterious effects of these health disorders. Sesamol, in particular, has been investigated for the treatment of several conditions because of it...

This article reports a computational kinetic and thermodynamic study of the chemical repair of radical-damaged tryptophan and tyrosine residues by the superoxide radical anion (O2•)- hydroperoxyl radical (HO2•) pair, via single electron transfer (SET) and formal hydrogen transfer (FHAT) mechanisms. It was demonstrated that O2• can repair oxidized...

New routes for the chemical formation of the C2O2H4 isomers in the gas phase are explored searching for a justification of the prominent astrophysical abundance of methyl formate with respect to the most stable one acetic acid. Kinetic rate constants at low temperatures are provided for 8 barrierless reaction pathways. In addition, the spectroscopi...

Five novel dimers in which the steroid cores are bridged by a 6,5,6‐trioxabispiroacetal moiety were synthesized by gold(I)‐catalyzed hydroalkoxylation–hydration of steroid diynediols. The double spiroacetalization proceeded with excellent yield and produced almost exclusively the C2 symmetrical trans diastereomer. A small amount of the cis unsymmet...

The ability of two novel amino-pyridinol based compounds (NPyr6 and NPyr7) as peroxyl radical scavengers was investigated in silico. The gathered data indicate that they are exceptionally efficient in that role. However, solvent polarity influences their relative efficiency for that purpose. NPyr6 was identified as the best peroxyl radical scavenge...

The potential role of nine thiols as chemical protectors against the toxicity of paracetamol (acetaminophen, APAP) and its meta analogue N-acetyl-m-aminophenol (AMAP) was investigated using the density functional theory. They are glutathione (GSH), N-acetylcysteine (NAC), NAC amide (NACA), tiopronine (TPR), dihydrolipoic acid (DHL), 6-mercaptopurin...

A systematic rational search for newly designed melatonin derivatives, was performed using a computer-assisted protocol. A total of 116 derivatives were generated by adding functional groups (i.e., -OH, -NH2, -SH and -COOH) to the melatonin structure. A selection score (SS) was built to sample the search space, simultaneously considering ADME (abso...

The superoxide radical anion can repair oxidative damage. Particularly, it was demonstrated that O2• can repair oxidized DNA by electron transfer, restoring the original structure of this important molecule. Acid-base...

Oxidative stress mediates chemical damage to DNA yielding a wide variety of products. In this work, the potential capability of melatonin and several of its metabolites to repair directly (chemically) oxidative lesions in DNA was explored. It was found that all the investigated molecules are capable of repairing guanine‐centered radical cations by...

The reactions of two plant hormones, namely jasmonic acid (JA) and methyl jasmonate (MJ), with different reactive oxygen species (ROS) were investigated using the density functional theory. Different reaction sites and mechanisms were explored, as well as solvents of different polarity, and pH in aqueous solution. The thermochemical viability and k...

Melatonin exhibits extraordinary diversity in terms of its functions and distribution. When discovered, it was thought to be uniquely of pineal gland origin. Subsequently, melatonin synthesis was identified in a variety of organs and recently it was shown to be produced in the mitochondria. Since mitochondria exist in every cell, with a few excepti...

Acute, or chronic, ethanol consumption leads to the formation of free radicals in the liver, which is related to hepatic damage. Among these radicals 1-hydroxyethyl, •CH(OH)CH3, is the most abundant one. Thus, efficient •CH(OH)CH3 scavengers are likely candidates to offer liver protection after ethanol consumption. In the present work ergosterol an...

Oxidative stress (OS) represents a threat to the chemical integrity of biomolecules including lipids, proteins and DNA. The associated molecular damage frequently results in serious health issues, which justifies our concern about this phenomenon. In addition to enzymatic defense mechanisms, there are compounds (usually referred to as antioxidants)...

Oxidative stress (OS) is a health-threatening process that is involved, at least partially, in the development of several diseases. Although antioxidants can be used as a chemical defense against OS, they might also exhibit pro-oxidant effects, depending on environmental conditions. In this work, such a dual behavior was investigated for phenolic c...

In this investigation, the capacity of citric acid as copper scavenger is analyzed. For the copper scavenger capacity, the formation of the chelate complexes is studied using the Gibbs free energies. The chelates may be formed since the formation reactions are all exergonic. The free radical scavenger ability of chelate complexes is investigated us...

The possible antioxidant reaction mechanisms of recently synthetized and tested alkylseleno (telluro) phenols have been explored by using density functional theory considering two solvents physiologically relevant, water and pentylethanoate (PE). In addition, the possible pathway for the antioxidant regeneration with ascorbic acid has been investig...

A novel steroid molecular rotor was obtained in four steps from the naturally occurring spirostane sapogenin diosgenin. The structural and dynamic characterization was carried out by solution NMR, VT X-ray diffraction, solid state 13C CPMAS and solid state 2H NMR experiments. They allowed the identification of a fast dynamic process with a frequenc...

Oxidative damage to DNA has important implications for human health and has been identified as a key factor in the onset and development of numerous diseases. Thus, it is evident that preventing DNA from oxidative damage is crucial for humans and for any living organism. Melatonin is an astonishingly versatile molecule in this context. It can offer...

Melatonin, along with its metabolites, have long been known to significantly reduce the oxidative stress burden of aging cells or cells exposed to toxins. Oxidative damage is a result of free radicals produced in cells, especially in mitochondria. When measured, melatonin, a potent antioxidant, was found to be in higher concentrations in mitochondr...

Oxidative stress, which is frequently induced by an overproduction of free radicals (FR), poses a high risk to human health. Thus, finding efficient strategies for scavenging FR is a research area of current interest. Among many other aspects, this involves identifying chemical compounds capable of offering antioxidant protection (AOP) and quantify...

Two empirically fitted parameters (m and C0) for the calculation of pKa values for thiols are provided for the first time, at 74 levels of theory. The coefficients were obtained by least-squares fits of the difference in Gibbs energy between each acid and its conjugated base versus experimental pKa values. The reliability of this fitted parameters...

Melatonin is an ancient antioxidant. After its initial development in bacteria, it has been retained throughout evolution such that it may be or may have been present in every species that have existed. Even though it has been maintained throughout evolution during the diversification of species, melatonin’s chemical structure has never changed; th...

Oxidative damage to biomolecules is a serious health-threatening issue, which leads to the development of several diseases. Oxidative conditions are frequently catalyzed by metal ions. In this study, the role of purines in the copper-catalyzed oxidative stress was investigated using the density functional theory. The obtained results indicate that...

Background: Oxidative stress (OS) arises when the balance between the production of oxidants and their removal is disturbed; OS is associated with a wide variety of health disorders. Finding strategies that efficiently reduce OS is an active area of research. Objective: This review summarizes the chemical insights concerning the antioxidant capacit...

Oxidative stress is frequently caused by an excess of free radicals and has been associated with a wide variety of health disor-ders. Therefore, finding strategies for scavenging free radicals has be-come an active area of research. This review summarizes, from a physicochemical perspective, relevant strategies to fight oxidative stress via antioxi...

This work provides a combined theoretical-experimental investigation on the relationship between structural features and energetic requirements of pyrolytic breakdown of solid lignin, with a focus on the loss of aromaticity in the likely products. The breaking of β-O-4 linkages was identified as the most likely route for the fragmentation of solid...

A massive search for chemical routes leading to methanol formation in gas phase has been conducted using computational chemistry, at CBS-QB3 level of theory. The calculations were performed at five different temperatures (100, 80, 50, 20 and 10 K) and at three pressures (0.1, 0.01 and 0.001 atm) for each temperature. The search was focused on ident...

The Mexican Petroleum Institute (IMP) is a national centre dedicated to basic and applied scientific research and is intended to develop technological solutions to the petroleum and energy industry challenges, form specialized human resources, and provide scientific, engineering and technical support to Petróleos Mexicanos (PEMEX) and new energy co...

Therapeutic chelating agents are used to prevent the effects of the metal accumulation. These are molecules that form complexes with transition metals and they are referred here as metal scavengers. The main idea of this investigation is to recognize the most relevant chemical features to identify potential metal scavengers. d-penicillamine with co...

The production of controlled release systems for Diuron aims to reduce some disadvantages of its conventional application and to diminish the associated environmental pollution. In this work, a matrix of urea–formaldehyde containing micro-encapsulated Diuron (Diuron–UF) is proposed to that purpose. The results of the morphology and distribution of...

Background: Melatonin is well known for its antioxidant capacity, which has been attributed to the combined protective effects of the parent molecule and its metabolites. However, the potential role of 2-hydroxymelatonin (2OHM) and 4-hydroxymelatonin (4OHM) in such protection has not been previously investigated. Methods: The calculations were p...

Elucidating the most likely deprotonation routes for polyprotic molecules is crucial in order to know the structures of the species prevailing under specific pH conditions. This is particularly important for molecules with potential applications as medical drugs, since different acid-base species, with the same deprotonation degree, may not interac...

DFT calculations have been performed to examine both direct and cluster-assisted methane C-H bond activation by Nb+ and Ta+ cations. The commonly accepted dehydrogenation pathways, that is oxidative addition and reductive elimination, have been studied in detail for methane ligated clusters M(CH4)n+ (M=Nb, Ta and n=1-4). For the second H atom trans...

The results presented in this work demonstrated the high complexity of chemical reactions involving species with multiple acid-base equilibria. For the study case investigated here, it was necessary to consider two radical species for tryptophan (Trp(-H)● and Trp●+) and three fractions for uric acid (H3Ur, H2Ur― and HUr2―) in order to properly repr...

Several chemical routes related to the toxicity of paracetamol (APAP, also known as acetaminophen), its analog N-acetyl-m-aminophenol (AMAP), and their deacetylated derivatives, were investigated using the Density Functional Theory. It was found that AMAP is more resilient to chemical oxidation than APAP. The chemical degradation of AMAP into radic...

The mechanism of the spontaneous decomposition of a mixture of 4-nitrophenylacetic acid (NO2BzCOOH) with its respective tetrabutylammonium carboxylate in acetonitrile (NO2BzCOO⁻) was analyzed using cyclic voltammetry, atomic force microscopy, nuclear magnetic resonance and electronic structure calculations. This reaction is favoured by the high aci...

The π-π stacking interactions does not necessarily change the mechanism involved in the H transfer reaction between phenol and phenoxyl radical. Our proposal is that, in such cases, the e- is transferred between the π delocalized moieties while the H+ is transferred between the donor-acceptor atoms.

The antioxidant and pro-oxidant behavior of 3-hydroxyanthranilic acid was investigated using Density Functional Theory. In the absence of metal ions 3-hydroxyanthranilic acid would act as an excellent antioxidant by scavenging free radicals. It was found to be an excellent peroxyl radical scavenger in both lipid and aqueous solution, reacting with...

There is currently no doubt about the serious threat that oxidative stress (OS) poses to human health. Therefore, a crucial strategy to maintain a good health status is to identify molecules capable of offering protection against OS through chemical routes. Based on the known efficiency of the phenolic and melatonin (MLT) families of compounds as a...

The potential ability of single-walled silicon-carbon nanotubes (SWSiCNT) as CO2 scavengers was investigated using density functional theory calculations and (5,5) SWSiCNT models with 2%, 33% and 50% Si. It was found that while the reactions between CO2 and pristine C tubes are endergonic, Si doped materials have exergonic adsorption routes. It was...

Valence, vertical ionization energies of a representative set of closed-shell molecules were calculated with the symmetry-adapted-cluster, configuration-interaction (SAC-CI) method using ten basis sets for its level 1 and level 2 operator inclusion criteria, whereas for its more stringent level 3 scheme, 15 basis sets were used. SAC-CI level 3 is c...

Two empirically fitted parameters have been derived for 74 levels of theory. They allow fast and reliable pKa calculations using only the Gibbs energy difference between an acid and its conjugated base in aqueous solution (ΔGs(BA)). The parameters were obtained by least-squares fits of ΔGs(BA) vs. experimental pKa values for phenols, carboxylic aci...

The pKa values for two compounds (LQM303 and LQM314) with antihypertensive properties were determined by UV spectroscopy (T = 310.15 K and I = 0.15 M) and by Capillary Zone Electrophoresis (T = 310.15 K and I = 0.05 M), using the program SQUAD. The partition coefficients (logP) between water and 1-octanol have also been determined experimentally, d...

The electron donor ability of 37 melatonin (MLT) derivatives was investigated at the LC-ωPBE/6–311+G(d) level of theory, which was chosen based on a benchmark study using the experimental vertical ionization energy of MLT as the reference value. Twenty-three of these derivatives had been already synthesized, while 14 are proposed here for the first...

In this review, we briefly summarize the reliability of the density functional theory (DFT)-based methods to accurately predict the main antioxidant properties and the reaction mechanisms involved in the free radical-scavenging reactions of chemical compounds present in food. The analyzed properties are the bond dissociation energies, in particular...

The diclofenac (DCF) electrochemical oxidation mechanism was studied through: linear voltammetry (LV), chronoamperometry (CA) sampled-current voltammetry (SCV), potentiostatic coulometry (PC) cyclic voltammetry (CV) under stagnant conditions and linear voltammetry under forced convection conditions (FCLV) over a carbon paste electrode (CPE) from an...

A set of 19 melatonin analogues, intended to be better antioxidants than the parent molecule, have been computationally designed. Eight of them were planned to have good primary antioxidant capacity (AOC), i.e., being good free radical scavengers. Seven of them were designed for their secondary AOC, able of inhibiting •OH production by acting as me...

The role of the acid–base equilibria and the sequential proton loss electron transfer mechanism (SPLET) on the free radical scavenging activity of six melatonin-related compounds was investigated using the density functional theory. It was found that this chemical route is particularly important for about half of the studied compounds. Some of thei...

Graphene nanosheets with heterogeneously doped nitrogen atoms are synthesized using a facile one-step method based on extremely rapid heating (temperature ramps ≥ 150 °C s−1). Raman and X-ray photoelectron spectroscopy reveal efficacious nitrogen incorporation into the graphitic network. A half-cell testing conducted in alkaline media with a rotati...

Acidity constants of mangiferin (H4MGF) in DMSO/H2O (80%/20%, v/v) were determined by UV-Visible and 1H and 13C NMR spectroscopies. UV-Visible absorption spectra in the 4.2 ≤ pH ≤ 11.7 range were fitted using the computational program SQUAD, for the refining of pKa values, obtaining as results: pKa1 = 7.337 ± 0.001, pKa2 = 8.936 ± 0.001, and pKa3 =...

Anthocyanidins are water-soluble flavonoids that have numerous beneficial effects to human and animal health. At the same time, they present multiple acid-base equilibria that under physiological conditions may lead to a rather wide distribution of species. This particular feature might influence the activity and mechanism of action of anthocyanidi...

The performance of different computational protocols for predicting pKa values of carboxylic acids, in aqueous solution, has been evaluated by comparison with experimental data. A set of 14 carboxylic acids was used to that purpose, including both aliphatic and aromatic species, as well as molecules of different chemical complexity. Two general str...

The protection exerted by 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), a phenolic compound recently isolated from the Pacific oyster, against oxidative stress (OS) is investigated using the density functional theory. Our results indicate that DHMBA is an outstanding peroxyl radical scavenger, being about 15 times and four orders of magnitude bett...