Papers by Ernesto Sánchez Mendoza
International Journal of Molecular Sciences, Nov 30, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Pharmaceuticals
Background: Inflammation is a complex process as a response to several stimuli, such as infection... more Background: Inflammation is a complex process as a response to several stimuli, such as infection, a chemical irritant, and the attack of a foreign body. Piquerol was isolated from Piqueria trinervia, and its anti-inflammatory activity was evaluated using in vivo and in vitro models. Methods: Piquerol is a monoterpene that was identified using NMR, FT-IR spectroscopy, and mass spectrometry analysis. The anti-inflammatory activity was tested in vivo in ear edema induced with TPA in mice. Piquerol was also tested on J774A.1 macrophages stimulated with lipopolysaccharide (LPS), and the levels of NO, NF-κB, TNF-α, IL-1β, IL-6, and IL-10 were determined using ELISA. Results: The results show that piquerol diminished ear edema (66.19%). At 150.51 µM, it also inhibited the levels of NO (31.7%), TNF-α (49.8%), IL-1β (69.9%), IL-6 (47.5%), and NF-κB (26.7%), and increased the production of IL-10 (62.3%). Piquerol has a membrane stabilization property in erythrocyte, and at 100 µg/mL, the mem...
Una aproximación a la espectroscopía de Resonancia Magnética Nuclear
Muchas de las propiedades y funciones que presenta un compuesto químico, son propiedades de su es... more Muchas de las propiedades y funciones que presenta un compuesto químico, son propiedades de su estructura; su conformación molecular le confiere propiedades únicas con enormes aplicaciones en química, biología, farmacia, ciencia de materiales, etc. La espectroscopía de Resonancia Magnética Nuclear (RMN) se ha consolidado como una herramienta clave para conocer la estructura tridimensional de las moléculas. Esta técnica provee información detallada sobre la dinámica y el ambiente químico que rodea a las moléculas. El desarrollo vertiginoso de su teoría y el gran avance tecnológico han hecho posible que puedan estudiarse e identificarse estructuras tridimensionales de proteínas de más de 800 residuos con gran precisión. En el presente capítulo, se pretende dar un panorama general del “fenómeno de la RMN”, haciendo énfasis en los principios básicos de su teoría.
The stereochemistry of nucleoside derivatives determines their pharmacological activity such as a... more The stereochemistry of nucleoside derivatives determines their pharmacological activity such as anticancer, antiviral, against human immunodeficiency virus (HIV) and antimycotic. Therefore, it is necessary to elucidate the structure of each stereoisomer. The isolation and spectroscopic characterization of the 1-(2´, 3´-<i>O</i>-isopropylidene-(α-D-allo and -β-L-talofuranosyluron)-5´-cyanohydrin)uracil stereoisomer is of great importance because these compounds are intermediaries in the development of novel nucleoside derivatives. In this study, we elucidated the structure of 5´(<i>R</i>) and (<i>S</i>)-cyanohydrin stereoisomers by NMR spectroscopy and tridimensional analysis. The structure was modeled based on the conformer with the local minimized energy. 1D-NOESY gave a detailed information about the tridimensional structure of each diastereoisomer. The ratio of the diastereoisomers determined by NMR, using DMSO-d<sub>6</sub> as solv...
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Nucleoside derivatives are important sources of biologically active compounds and are widely used... more Nucleoside derivatives are important sources of biologically active compounds and are widely used in agrochemistry as herbicides, [1] fungicides and insecticides, [2] and as therapeutic agents. [3–8] Currently, the FDA has approved approximately 40 nucleoside derivatives for the treatment of cancer and antiviral therapies; however, some of these compounds have severe side effects. [5, 9, 10] Therefore, it is important to conduct research concerning new nucleosides with high pharmacological activity and low toxicity.
Natural Product Research, 2020
Biomolecules, 2020
Haemonchus contortus affect small ruminants all over the world. Anthelmintics cause resistance, c... more Haemonchus contortus affect small ruminants all over the world. Anthelmintics cause resistance, contamination, and a risk of public health. Prosopis laevigata is a plant used as a home remedy against many diseases in Mexico. This study arose from a preliminary study where a P. laevigata hydroalcoholic extract (Pl-hae) showed anthelmintic activity (aa) against H. contortus. Searching for bioactive compounds (bac) with high aa, the Pl-hae was fractioned obtaining an aqueous (Aq-F) and an ethyl acetate fraction (EtAc-F), and a flavonoid with aa identified as isorhamnetin was obtained from EtAc-F. Both fractions were in vitro assessed by the egg hatch test (eht) and larval mortality (lm) assays. The bac obtained from EtAc-F were characterised by NMR analysis. The highest aa were recorded with EtAc-F, resulting in 100% eht and 80.45% lm at 0.75 and 30 mg/mL, respectively. Alterations in eggs and larvae attributed to isorhamnetin were recorded by environmental scanning electron microscopy...
Drug Development Research, 2018
Salvia tiliifolia Vahl (Lamiaceae) is used for the empirical treatment of pain and inflammation. ... more Salvia tiliifolia Vahl (Lamiaceae) is used for the empirical treatment of pain and inflammation. The diterpenoid tilifodiolide (TFD) was isolated from Salvia tiliifolia. The in vitro anti‐inflammatory effects of TFD (0.1–200 µM) were assessed using murine macrophages stimulated with LPS and estimating the levels of pro‐inflammatory mediators for 48 h. The in vivo anti‐inflammatory activity of TFD was assessed using the carrageenan‐induced paw edema test for 6 h. The antinociceptive effects of TFD were evaluated using the formalin test and the acetic acid induced‐writhing test. The effects of TFD on locomotor activity were assessed using the open field test and the rotarod test. TFD inhibited the production of TNF‐α (IC50 = 5.66 µM) and IL‐6 (IC50 = 1.21 µM) in macrophages. TFD (200 mg/kg) showed anti‐inflammatory effects with similar activity compared to 10 mg/kg indomethacin. The administration of TFD induced antinociception in the phase 1 (ED50 = 48.2 mg/kg) and the phase 2 (ED50 = 28.9 mg/kg) of the formalin test. In the acetic acid assay, TFD showed antinociceptive effects (ED50 = 32.3 mg/kg) with similar potency compared to naproxen (ED50 = 36.2 mg/kg). In the presence of different inhibitors in the acetic acid assay, only the co‐administration of TFD and naloxone reverted the antinociceptive activity shown by TFD alone. TFD did not affect locomotor activity in mice. TFD exerts in vitro and in vivo anti‐inflammatory activity and in vivo antinociceptive effects.
Pharmaceutical Biology, 2017
Context: A previous study demonstrated that the chloroform extract of Salvia connivens Epling (La... more Context: A previous study demonstrated that the chloroform extract of Salvia connivens Epling (Lamiaceae) has anti-inflammatory activity. Objective: Identification of the active components in the dicholorometane extract (DESC), and, standardization of the extract based in ursolic acid. Material and methods: DESC was prepared by percolation with dichlromethane and after washed with hot hexane, its composition was determined by CG-MS and NMR, and standardized by HPLC. The antiinflammatory activity was tested on acute TPA-induced mouse ear oedema at doses of 2.0 mg/ear. The cell viability of macrophages was evaluated by MTT method, and pro-and anti-inflammatory interleukin levels were measured using an ELISA kit. Results: Ursolic acid, oleanolic acid, dihydroursolic acid and eupatorin were identified in DESC, which was standardized based on the ursolic acid concentration (126 mg/g). The anti-inflammatory activities of DESC, the acid mixture, and eupatorin (2 mg/ear) were 60.55, 57.20 and 56.40% inhibition, respectively, on TPAinduced ear oedema. The IC 50 of DESC on macrophages was 149.4 lg/mL. DESC (25 lg/mL) significantly reduced TNF-a (2.0-fold), IL-1b (2.2-fold) and IL-6 (2.0-fold) in macrophages stimulated with LPS and increased the production of IL-10 (1.9-fold). Discussion: Inflammation is a basic response to injuries, and macrophages are involved in triggering inflammation. Macrophage cells exhibit a response to LPS, inducing inflammatory mediators, and DESC inhibits the biosynthesis of the pro-inflammatory and promote anti-inflammatory cytokines. Conclusion: DESC has an anti-inflammatory effect; reduced the levels of IL-1b, Il-6 and TNF-a; and increases IL-10 in macrophages stimulated with LPS. Ursolic acid is a good phytochemical marker.
Revista Brasileira de Farmacognosia, 2017
New compounds with chemotherapeutic activity are sought after, and plants are an important source... more New compounds with chemotherapeutic activity are sought after, and plants are an important source of these compounds. Four diterpenes, 19-deoxyicetexone, 7,20-dihydroanastomosine, icetexone and 19deoxyisoicetexone, were isolated from the hexane-washed chloroform extract of Salvia ballotiflora. The cytotoxic activity of the hexane-washed chloroform extract and its four diterpenes were tested using the MTT assay against three tumor cell lines: HeLa (cervical cancer), A549 (lung cancer) and MCF7 (breast cancer), and two murine cell line: J774A.1 (epithelial cancer) and CT26 (colon cancer), and their IC 50 values were determined. 19-Deoxyisoicetexone had the greatest effect on HeLa cells with IC 50 of 3.2 g/ml (9.36 M), whereas hexane-washed chloroform extract had the best cytotoxic effect on A549 cells with an IC 50 of 2.29 g/ml. These effects of 19-deoxyisoicetexone and hexane-washed chloroform extract were with similar activity compared to cisplatin (IC 50 = 1.06 g/ml in HeLa cells, and 4.6 g/ml (15.21 M) in A549 cells).
Magnetic resonance in chemistry : MRC, Jan 14, 2017
A structural study of new diastereoisomeric 5'(R and S)-cyanohydrins nucleosides that are imp... more A structural study of new diastereoisomeric 5'(R and S)-cyanohydrins nucleosides that are important intermediates for antibiotics and antimycotics, such as polyoxins and nikkomycins, was performed using experimental NMR, theoretical methods and 3D analysis. The structures of these compounds were elucidated, and modeling was based on the conformer with the local minimized energy. The calculated and experimentally determined values are in good agreement (Supporting Information).
The discovery and development of insecticides isolated from natural products is a growing area of... more The discovery and development of insecticides isolated from natural products is a growing area of agricultural research. Here we show that kramecyne, is cyclic peroxide obtained from Krameria cytisoides, has insecticidal activity against Spodoptera frugiperda. The insecticidal and insectistatic activities of kramecyne against S. frugiperda were tested at different concentrations. Larval duration increased by 6.8 d and 18.9 d at doses of 500 and 700 ppm, respectively, whereas the pupal period increased by 3.0 d and 6.5 d under those concentrations. Larval viability was 0%, 16.7%, and 33.3% when the compound was applied at 1000, 700, and 500 ppm, respectively. At 700 and 500 ppm, pupal viability was 25.4% and 50.0%, respectively, and pupal weight decreased by 16.7% and 57.0%. The LV 50 of kramecyne was 389.3 ppm. Kramecyne isolated from K. cytisoides shows potent activity against larvae and pupae of S. frugiperda at low concentrations.
Drug development research, 2015
Preclinical Research Krameria cytisoides is used for the treatment of inflammation, stomach pain,... more Preclinical Research Krameria cytisoides is used for the treatment of inflammation, stomach pain, and gastric ulcers. The active ingredient from this plant is a peroxide, kramecyne (KACY) which has anti-inflammatory effects. The aim of the present study was to evaluate the anti-inflammatory activities of KACY in lipopolysaccharide (LPS)-induced systemic chronic inflammation in mice for 60 days, using dexamethasone (DEX) as the positive control, vehicle (the LPS group) as the negative control and the control group (mice without inflammation). KACY did not affect survival, body weight or relative organ weight in mice but it: decreased nitric oxide (NO) production by 68%; prostaglandin E2 (PGE2 ) by 67%; increased release of anti-inflammatory cytokine IL-10 (2.0-fold), and reduced production of the proinflammatory cytokines, IL-6 (2.0-fold), IL-1β (2.4-fold), and TNF-α (2.0-fold). Furthermore, the gastroprotective effects of KACY in mice were evaluated in an ethanol-induced gastric ulc...
Life Sciences, 2015
The aim of this study was to evaluate the antinociceptive (acute assays) and anti-inflammatory (c... more The aim of this study was to evaluate the antinociceptive (acute assays) and anti-inflammatory (chronic assays) effects of kramecyne (KACY), a peroxide isolated from Krameria cytisoides. Main methods: The antinociceptive activity of KACY was evaluated using the hot plate, acetic acid and formalin tests. The effects of KACY on heat-induced hemolysis in rat erythrocytes were also evaluated. The in vivo antiinflammatory assays were performed using the chronic TPA (12-O-tetradecanoylphorbol 13-acetate) method to induce ear edema and carrageenan-kaolin induced arthritis (CKIA). In the CKIA model, the hot plate test was performed, serum samples were obtained for the quantitation of pro-inflammatory (IL-1β, IL-6, IL-12 and TNF-α) and anti-inflammatory (IL-4 and IL-10) cytokines. Key findings: KACY possess antinociceptive effects with comparable activity to naproxen (NPX). KACY inhibited hemolysis (EC 50 = 180 μg/mL), in comparison to the untreated group and with a higher potency than NPX (EC 50 = 263 μg/mL). KACY at 50 mg/kg decreased inflammation by 38% (chronic TPA-induced edema model) and by 26% (CKIA model), in comparison with the vehicle group and with similar activity to the positive controls 8 mg/kg indomethacin (IND) and 1 mg/kg methotrexate (MTX), respectively. In the CKIA model, KACY increased the release of anti-inflammatory (IL-4 and IL-10) cytokines but reduced the production of pro-inflammatory cytokines (IL-1β, IL-6, IL-12 and TNF-α). KACY at 50 and 100 mg/kg showed antinociceptive effects by 27% and 23%, respectively, in mice with mono-arthritis. Significance: KACY might be a good alternative for the treatment of rheumatoid arthritis (RA) due its antinociceptive and anti-inflammatory activities.
The Journal of Physical Chemistry A, 2007
We studied vicinal and long-range coupling constants for 9-anthracene derivatives, e.g., Br, CN, ... more We studied vicinal and long-range coupling constants for 9-anthracene derivatives, e.g., Br, CN, CHO, NO 2 , CH 2 Cl, CH 2 OH, and OCH 3. We performed the accurate measurements using modified J doubling in the frequency domain, even for the smallest couplings immersed within the line width. Density functional theory allowed us to reproduce and exhaustively analyze the physical contributions to the values of these spectroscopic parameters. The theory of atoms in molecules defines a delocalization index that correlates linearly with vicinal and long-range coupling constants when they are grouped in terms of the number of bonds between the coupled nuclei. An exception to this behavior is obtained for 4 J H4,H10 values, which have a negative Fermi contact and the largest delocalization index for each molecule. This observation can be explained by a characteristic "gable roof" arrangement formed by the five nuclei involved in the coupling.
Molecules, 2013
The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflor... more The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflora were evaluated on castor oil-, arachidonic acid (AA)-and prostaglandin (PGE 2)-induced diarrhea in rodent models. The structure of 19-deoxyicetexone was determined by X-ray crystallography, mass spectrometry (EI-MS), as well as ultraviolet (UV-Vis), infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. This compound significantly and dose-dependently reduced frequency of stooling in castor oil-induced diarrhea, and at dose of 25 mg/kg it also inhibited diarrhea induced with AA, while it had no effect on PGE 2-induced diarrhea. This compound at doses of 25 mg/kg also diminished castor oil-induced enteropooling and intestinal motility, and inhibited the contraction of the rats' ileum induced by carbachol chloride at a concentration of 100 µg/mL. 19-Deoxyicetexone did not present acute toxicity at doses of 625 mg/kg. Its antidiarrheal activity may be due to increased reabsorption of NaCl and water and inhibition of the release of prostaglandins, gastrointestinal motility and fluid accumulation in the intestinal tracts of rats. These findings suggest that 19-deoxyicetexone may be used in the treatment of diarrhea, although more studies must be carried out to confirm this.
Molecules, 2012
In the present work we describe the structure and anti-inflammatory activity of a new compound, k... more In the present work we describe the structure and anti-inflammatory activity of a new compound, kramecyne, isolated from a methanol extract of Krameria cytisoides (Krameriaceae). The structure of kramecyne was determined by IR, NMR, MS, and elemental analysis, which indicated that the structure corresponded to a hexamer of cyclic peroxide monomers. This compound exhibited good anti-inflammatory activity in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema (51.8 ± 6.9% inhibition) and carrageenan-induced rat paw edema models at doses of 50 mg/kg. The compound significantly reduced edema to 63.1% after 1.0 h, and the effect was unchanged for 5 h. Kramecyne did not present acute toxicity, even at doses of 5,000 mg/kg.
Magnetic Resonance in Chemistry, 2010
The indirect vicinal proton-proton coupling constants for pyrrole, furan, thiophene and 15 relate... more The indirect vicinal proton-proton coupling constants for pyrrole, furan, thiophene and 15 related heteroaromatic compounds were calculated using the Khon-Sham approximation. An analysis of the four Ramsey contributions to the coupling constants was carried out showing that the Fermi contact term is always positive and dominant, although the remaining contributions have a nonnegligible net negative contribution. The trends observed for the proton-proton coupling constants were rationalized in terms of the properties of the electron density. It was found that electron delocalization between the corresponding hydrogen atoms plays a major role on the observed behavior with the charges of the carbon atoms bonded to them and the accompanying geometric variations being also of importance in the coupling mechanism.
Arkivoc, 2004
Pattern recognition is extremely important for both structure elucidation and stereochemical stud... more Pattern recognition is extremely important for both structure elucidation and stereochemical studies as a means for the measurement of spin-spin coupling constants. Many treatises deal with the formation of splitting trees to create a pattern for a given set of spin-spin coupling constants. We present here a general systematic procedure to easily analyze first order multiplets in NMR spectroscopy. This method has the advantage of measuring coupling constants while deconvolving the signals at the same time using an extension of the modified J doubling in the frequency domain.
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Papers by Ernesto Sánchez Mendoza