Publications by authors named "Luiz Alberto Beraldo de Moraes"

17 Publications

  • Page 1 of 1

Extraction of carotenoid-rich palm pressed fiber oil using mixtures of hydrocarbons and short chain alcohols.

Food Res Int 2020 02 21;128:108810. Epub 2019 Nov 21.

Laboratório de Engenharia de Separações (LES), Departamento de Engenharia de Alimentos (ZEA), Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), Universidade de São Paulo (USP), 13635-900 Pirassununga, São Paulo, Brazil. Electronic address:

Solvent extraction is the most efficient method for recovering residual oil from palm pressed fiber (PPFO), which may contain up to eight times the carotenoid content of that found in crude palm oil. The objective of the present study is the use of binary mixtures of hydrocarbons (HC), hexane (Hex), cyclohexane (CHex) or heptane (Hep), and alcohols (ALC), ethanol (Eth) or isopropanol (IPA), in order to promote the highest recovery of a carotenoid-rich PPFO, in which the compositions of the mixtures are defined based on the calculation of solute-solvent distance (Ra) considering β-carotene as the solute. The extraction experiments were conducted in batch, at 60 ± 2 °C, or in a fixed-bed packed column, at 55 ± 3 °C. Hex and Hep:IPA provided 80% of batch PPFO extraction yield, while in column, the highest yields were obtained with Eth and Hex:IPA (66%). The total carotenoid content obtained was the same independent of the solvent and extraction configuration (from 1790 ± 230 up to 2539 ± 78 mg β-carotene/kg PPFO). In terms of the carotenoid profile, β-carotene was mostly extracted by Hex, Hex:Eth stood out in the extraction of α-carotene, and Eth extracted the highest content of lycopene. It is possible to infer that mixtures of HC and ALC with compositions defined based on Hansen Solubility Parameters (HSPs) demonstrated good ability to extract carotenoid-rich PPFO, maintaining their relatively stable fatty acids composition and free acidity, showing that partial substitution of HC by ALC is technically possible.
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http://dx.doi.org/10.1016/j.foodres.2019.108810DOI Listing
February 2020

Pradimicin-IRD exhibits antineoplastic effects by inducing DNA damage in colon cancer cells.

Biochem Pharmacol 2019 10 19;168:38-47. Epub 2019 Jun 19.

Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. Electronic address:

DNA-damaging agents are widely used in cancer therapy; however, their use is limited by dose-related toxicities, as well as the development of drug resistance. Drug discovery is essential to overcome these limitations and offer novel therapeutic options. In a previous study by our research group, pradimicin-IRD-a new polycyclic antibiotic produced by the actinobacteria Amycolatopsis sp.-displayed antimicrobial and potential anticancer activities. In the present study, cytotoxic activity was further confirmed in a panel of five colon cancer, including those with mutation in TP53 and KRAS, the most common ones observed in cancer colon patients. While all tested colon cancer cells were sensitive to pradimicin-IRD treatment with IC in micromolar range, non-tumor fibroblasts were significantly less sensitive (p < 0.05). The cellular and molecular mechanism of action of pradimicin-IRD was then investigated in the colorectal cancer cell line HCT 116. Pradimicin-IRD presented antitumor effects occurring after at least 6 h of exposure. Pradimicin-IRD induced statistically significant DNA damage (γH2AX and p21), apoptosis (PARP1 and caspase 3 cleavage) and cell cycle arrest (reduced Rb phosphorylation, cyclin A and cyclin B expression) markers. In accordance with these results, pradimicin-IRD increased cell populations in the subG and G/G phases of the cell cycle. Additionally, mass spectrometry analysis indicated that pradimicin-IRD interacted with the DNA double strand. In summary, pradimicin-IRD exhibits multiple antineoplastic activities-including DNA damage, cell cycle arrest, reduction of clonal growth and apoptosis-in the HCT 116 cell line. Furthermore, pradimicin-IRD displays a TP53-independent regulation of p21 expression in HCT 116 TP53, HT-29, SW480, and Caco-2 cells. This exploratory study identified novel targets for pradimicin-IRD and provided insights for its potential anticancer activity as a DNA-damaging agent.
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http://dx.doi.org/10.1016/j.bcp.2019.06.016DOI Listing
October 2019

Characterization of Casearin X Metabolism by Rat and Human Liver Microsomes.

Planta Med 2019 Mar 29;85(4):282-291. Epub 2018 Oct 29.

Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.

Casearin X (CAS X) is the major clerodane diterpene isolated from the leaves of and has been extensively studied due to its powerful cytotoxic activity at low concentrations. Promising results for antitumor action have also been described when CAS X was administered intraperitoneally in mice. Conversely, loss of activity was observed when orally administered. Since the advancement of natural products as drug candidates requires satisfactory bioavailability for their pharmacological effect, this work aimed to characterize the CAS X metabolism by employing an microsomal model for the prediction of preclinical pharmacokinetic data. Rat and human liver microsomes were used to assess species differences. A high-performance liquid chromatography with diode-array detection (HPLC-DAD) method for the quantification of CAS X in microsomes was developed and validated according to European Medicines Agency guidelines. CAS X was demonstrated to be a substrate for carboxylesterases via hydrolysis reaction, with a Michaelis-Menten kinetic profile. The enzyme kinetic parameters were determined, and the intrinsic clearance was 1.7-fold higher in humans than in rats. The hepatic clearance was estimated by - extrapolation, resulting in more than 90% of the hepatic blood flow for both species. A qualitative study was also carried out for the metabolite identification by mass spectrometry and indicated the formation of the inactive metabolite CAS X dialdehyde. These findings demonstrate that CAS X is susceptible to first-pass metabolism and is a substrate for specific carboxylesterases expressed in liver, which may contribute to a reduction in antitumor activity when administered by the oral route.
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http://dx.doi.org/10.1055/a-0765-9523DOI Listing
March 2019

Comprehensive high-resolution multiple-reaction monitoring mass spectrometry for targeted eicosanoid assays.

Sci Data 2018 08 21;5:180167. Epub 2018 Aug 21.

Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, Ribeirão Preto, São Paulo 14040-903, Brazil.

Eicosanoids comprise a class of bioactive lipids derived from a unique group of essential fatty acids that mediate a variety of important physiological functions. Owing to the structural diversity of these lipids, their analysis in biological samples is often a major challenge. Advancements in mass spectrometric have been helpful for the characterization and quantification of these molecular lipid species in complex matrices. However, there are technical limitations to this approach, including low-abundant and/or poorly ionizable lipids. Using high-resolution multiple-reaction monitoring (MRM), we were able to develop a targeted bioanalytical method for eicosanoid quantification. For this, we optimized the LC-MS/MS conditions and evaluated several parameters, including linearity, limits of quantification, matrix effects and recovery yields. For validation purposes, we looked at the method's precision and accuracy. A library of high-resolution fragmentation spectra for eicosanoids was developed. Our comprehensive dataset meets benchmark standards for targeted analysis, having been derived using best-practice workflows and rigorous quality assessments. As such, our method has applications for determining complex eicosanoid profiles in the biomedical field.
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http://dx.doi.org/10.1038/sdata.2018.167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6103261PMC
August 2018

High-resolution multiple reaction monitoring method for quantification of steroidal hormones in plasma.

J Mass Spectrom 2018 May;53(5):423-431

Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, Ribeirão Preto, São Paulo, 14040-903, Brazil.

Multiple reaction monitoring (MRM) is one of the most powerful modes of analysis in liquid chromatographic tandem mass spectrometry for quantification of low-concentration metabolites in biological samples. The advances in mass spectrometry enabled the development of high-resolution multiple reaction monitoring (MRM ) and became suitable for the more specific analysis of target analytes. This is important for lipidomic studies and contributes in the medical and pharmaceutical fields, primarily in investigating alterations in cells or fluids relevant to various diseases. Therefore, this work proposes the development of the MRM method for quantification of circulating steroids. We focused on the determination of corticosterone, 11-dehydrocorticosterone (11-DHC), cortisol, cortisone, aldosterone, and progesterone concentration in serum, by using 129sv male mice exposed to chronic unpredictable stress to validate the quantification. The method was conducted according to the ANVISA normative, adopting a coefficient of variation, as well as relative standard deviation and relative error lower than 15% in linearity, intraday and interday precision, and accuracy. For cortisol, corticosterone, and their inert metabolites (cortisone and 11-DHC), the lower limit of quantification was 3.9 ng· mL , while that for progesterone and aldosterone was 7.8 and 15.6 ng· mL , respectively. MRM analysis showed that animals submitted to stressors have 4.5 times more corticosterone in their serum than nonstressed mice. However, 11-DHC concentration does not vary significantly in response to stress for these animals. The results indicate that the method can be applied for quantification of steroids in several biological samples, such as human plasma.
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http://dx.doi.org/10.1002/jms.4075DOI Listing
May 2018

The gut microbiota of insecticide-resistant insects houses insecticide-degrading bacteria: A potential source for biotechnological exploitation.

PLoS One 2017 30;12(3):e0174754. Epub 2017 Mar 30.

Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Departamento de Entomologia e Acarologia, Piracicaba, São Paulo, Brasil.

The exploration of new niches for microorganisms capable of degrading recalcitrant molecules is still required. We hypothesized the gut microbiota associated with insect-resistant lines carry pesticide degrading bacteria, and predicted they carry bacteria selected to degrade pesticides they were resistant to. We isolated and accessed the pesticide-degrading capacity of gut bacteria from the gut of fifth instars of Spodoptera frugiperda strains resistant to lambda-cyhalothrin, deltamethrin, chlorpyrifos ethyl, spinosad and lufenuron, using insecticide-selective media. Sixteen isolates belonging to 10 phylotypes were obtained, from which four were also associated with the susceptible strain. However, growth of gut bacteria associated with larvae from the susceptible strain was not obtained in any of the insecticide-based selective media tested. Growth of isolates was affected by the concentration of insecticides in the media, and all grew well up to 40 μg/ml. The insecticide-degrading capacity of selected isolates was assessed by GC or LC-MS/MS analyses. In conclusion, resistant strains of S. frugiperda are an excellent reservoir of insecticide-degrading bacteria with bioremediation potential. Moreover, gut-associated bacteria are subjected to the selection pressure imposed by insecticides on their hosts and may influence the metabolization of pesticides in insects.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0174754PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373613PMC
August 2017

Degradation of textile dyes by cyanobacteria.

Braz J Microbiol 2017 Jan - Mar;48(1):25-31. Epub 2016 Oct 10.

Centro de Energia Nuclear na Agricultura, Laboratório de Ecologia Aplicada, Piracicaba, SP, Brazil. Electronic address:

Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.
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http://dx.doi.org/10.1016/j.bjm.2016.09.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5221351PMC
April 2017

Determination of Levetiracetam in Human Plasma by Dispersive Liquid-Liquid Microextraction Followed by Gas Chromatography-Mass Spectrometry.

J Anal Methods Chem 2016 17;2016:5976324. Epub 2016 Oct 17.

Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, 14040-903 Ribeirão Preto, SP, Brazil.

Levetiracetam (LEV) is an antiepileptic drug that is clinically effective in generalized and partial epilepsy syndromes. The use of this drug has been increasing in clinical practice and intra- or -interindividual variability has been exhibited for special population. For this reason, bioanalytical methods are required for drug monitoring in biological matrices. So this work presents a dispersive liquid-liquid microextraction method followed by gas chromatography-mass spectrometry (DLLME-GC-MS) for LEV quantification in human plasma. However, due to the matrix complexity a previous purification step is required. Unlike other pretreatment techniques presented in the literature, for the first time, a procedure employing ultrafiltration tubes Amicon® (10 kDa porous size) without organic solvent consumption was developed. GC-MS analyses were carried out using a linear temperature program, capillary fused silica column, and helium as the carrier gas. DLLME optimized parameters were type and volume of extraction and dispersing solvents, salt addition, and vortex agitation time. Under chosen parameters (extraction solvent: chloroform, 130 L; dispersing solvent: isopropyl alcohol, 400 L; no salt addition and no vortex agitation time), the method was completely validated and all parameters were in agreement with the literature recommendations. LEV was quantified in patient's plasma sample using less than 550 L of organic solvent.
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http://dx.doi.org/10.1155/2016/5976324DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5086507PMC
October 2016

Streptomyces atlanticus sp. nov., a novel actinomycete isolated from marine sponge Aplysina fulva (Pallas, 1766).

Antonie Van Leeuwenhoek 2016 Nov 26;109(11):1467-1474. Epub 2016 Aug 26.

College of Agriculture "Luiz de Queiroz", University of São Paulo, Av. Pádua Dias, 11, Piracicaba, 13418900, Brazil.

The taxonomic position of a novel marine actinomycete isolated from a marine sponge, Aplysina fulva, which had been collected in the Archipelago of Saint Peter and Saint Paul (Equatorial Atlantic Ocean), was determined by using a polyphasic approach. The organism showed a combination of morphological and chemotaxonomic characteristics consistent with its classification in the genus Streptomyces and forms a distinct branch within the Streptomyces somaliensis 16S rRNA gene tree subclade. It is closely related to Streptomyces violascens ISP 5183 (97.27 % 16S rRNA gene sequence similarity) and Streptomyces hydrogenans NBRC 13475 (97.15 % 16S rRNA gene sequence similarity). The 16S rRNA gene similarities between the isolate and the remaining members of the subclade are lower than 96.77 %. The organism can be distinguished readily from other members of the S. violacens subclade using a combination of phenotypic properties. On the basis of these results, it is proposed that isolate 103 (=NRRL B-65309 = CMAA 1378) merits recognition as the type strain of a new Streptomyces species, namely Streptomyces atlanticus sp. nov.
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http://dx.doi.org/10.1007/s10482-016-0748-8DOI Listing
November 2016

Plasma eicosanoid profiles determined by high-performance liquid chromatography coupled with tandem mass spectrometry in stimulated peripheral blood from healthy individuals and sickle cell anemia patients in treatment.

Anal Bioanal Chem 2016 May 11;408(13):3613-23. Epub 2016 Mar 11.

Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, Ribeirão Preto, São Paulo, 14040-903, Brazil.

Eicosanoids play an important role in homeostasis and in the pathogenesis of various human diseases. Pharmacological agents such as Ca(2+) ionophores and Ca(2+)-ATPase inhibitors, as well as natural agonists such as formylmethionine-leucyl-phenylalanine (fMLP), can stimulate eicosanoid biosynthesis. The aims of this work were to develop a method to determine the eicosanoid profile of human plasma samples after whole blood stimulation and to assess differences between healthy and sick individuals. For this purpose, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was partially validated for the quantification of 22 eicosanoids using human plasma from healthy volunteers. In addition, we optimized a method for the stimulation of eicosanoids in human whole blood. LC-MS/MS analyses were performed by negative electrospray ionization and multiple reaction monitoring. An assumption of linearity resulted in a regression coefficient ≥0.98 for all eicosanoids tested. The mean intra-assay and inter-assay accuracy and precision values had relative standard deviations and relative errors of ≤15%, except for the lower limit of quantification, where these values were ≤20%. For whole blood stimulation, four stimuli (fMLP, ionomycin, A23187, and thapsigargin) were tested. Results of the statistical analysis showed that A23187 and thapsigargin were potent stimuli for the production or liberation of eicosanoids. We next compared the eicosanoid profiles of stimulated whole blood samples of healthy volunteers to those of patients with sickle cell anemia (SCA) under treatment with hydroxyurea (HU) or after chronic red blood cell (RBC) transfusion. The results indicate that the method was sufficient to find a difference between lipid mediators released in whole blood of SCA patients and those of healthy subjects, mainly for 5-HETE, 12-HETE, LTB4, LTE4, TXB2, and PGE2. In conclusion, our analytical method can detect significant changes in eicosanoid profiles in stimulated whole blood, which will contribute to establishing the eicosanoid profiles associated with different inflammatory and infectious diseases.
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http://dx.doi.org/10.1007/s00216-016-9445-8DOI Listing
May 2016

Production and chemical characterization of pigments in filamentous fungi.

Microbiology (Reading) 2016 Jan 3;162(1):12-22. Epub 2015 Sep 3.

Department of Biology, Post-Graduate Program in Agriculture Microbiology, Federal University of Lavras, MG, Brazil.

Production of pigments by filamentous fungi is gaining interest owing to their use as food colourants, in cosmetics and textiles, and because of the important biological activities of these compounds. In this context, the objectives of this study were to select pigment-producing fungi, identify these fungi based on internal transcribed spacer sequences, evaluate the growth and pigment production of the selected strains on four different media, and characterize the major coloured metabolites in their extracts. Of the selected fungal strains, eight were identified as Aspergillus sydowii (CML2967), Aspergillus aureolatus (CML2964), Aspergillus keveii (CML2968), Penicillium flavigenum (CML2965), Penicillium chermesinum (CML2966), Epicoccum nigrum (CML2971), Lecanicillium aphanocladii (CML2970) and Fusarium sp. (CML2969). Fungal pigment production was influenced by medium composition. Complex media, such as potato dextrose and malt extract, favoured increased pigment production. The coloured compounds oosporein, orevactaene and dihydrotrichodimerol were identified in extracts of L. aphanocladii (CML2970), E. nigrum (CML2971), and P. flavigenum (CML2965), respectively. These results indicate that the selected fungal strains can serve as novel sources of pigments that have important industrial applications.
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http://dx.doi.org/10.1099/mic.0.000168DOI Listing
January 2016

Novel binuclear μ-oxo diruthenium complexes combined with ibuprofen and ketoprofen: Interaction with relevant target biomolecules and anti-allergic potential.

J Inorg Biochem 2015 Dec 8;153:178-185. Epub 2015 Aug 8.

Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, 14040-901 Ribeirão Preto -SP, Brazil. Electronic address:

This work presents the synthesis and characterization of two novel binuclear ruthenium compounds of general formula [Ru2O(carb)2(py)6](PF6)2, where py=pyridine and carb are the non-steroidal anti-inflammatory drugs ibuprofen (1) and ketoprofen (2). Both complexes were characterized by ESI-MS/MS spectrometry. The fragmentation patterns, which confirm the proposed structures, are presented. Besides that, compounds 1 and 2 present the charge transfer transitions within 325-330nm; and the intra-core transitions around 585nm, which is the typical spectra profile for [Ru2O] analogues. This suggests the carboxylate bridge has little influence in their electronic structure. The effects of the diruthenium complexes on Ig-E mediated mast cell activation were evaluated by measuring the enzyme β-hexosaminidase released by mast cells stimulated by antigen. The inhibitory potential of the ketoprofen complex against mast cell stimulation suggests its promising application as a therapeutic agent for treating or preventing IgE-mediated allergic diseases. In addition, in vitro metabolism assays had shown that the ibuprofen complex is metabolized by the cytochrome P450 enzymes.
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http://dx.doi.org/10.1016/j.jinorgbio.2015.08.004DOI Listing
December 2015

Immunomodulatory action of Copaifera spp oleoresins on cytokine production by human monocytes.

Biomed Pharmacother 2015 Mar 9;70:12-8. Epub 2015 Jan 9.

Department of Microbiology and Immunology, Biosciences Institute, UNESP, 18618-970, Botucatu, SP, Brazil. Electronic address:

Copaifera spp oleoresins have been used in folk medicine for centuries; nevertheless, its immunomodulatory action has not been investigated. Thus, the goal of this study was to characterize different oleoresins and to verify their action on human monocytes regarding pro- and anti-inflammatory cytokine production (TNF-α and IL-10, respectively). The chemical composition of Brazilian Copaifera reticulata, Copaifera duckey and Copaifera multijuga oleoresins was analyzed by HPLC-MS. Cell viability was assessed by MTT method after incubation of cells with Copaifera spp. Noncytotoxic concentrations of oleoresins were incubated with human monocytes from healthy donors, and cytokine production was determined by ELISA. HPLC-MS analysis for terpenes allowed the identification of six diterpene acids and one sesquiterpene acid. Oleoresins exerted no cytotoxic effects on human monocytes. All oleoresins had a similar profile: LPS-induced TNF-α production was maintained by oleoresins, while a significant inhibitory action on IL-10 production was seen. Copaifera oleoresins seemed to exert an activator profile on human monocytes without affecting cell viability. Such effect may be due to the presence of either diterpene or sesquiterpene acids; however, further studies are necessary to determine the involvement of such compounds in Copaifera immunomodulatory effects.
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http://dx.doi.org/10.1016/j.biopha.2014.12.035DOI Listing
March 2015

Simultaneous determination of amino acids and neurotransmitters in plasma samples from schizophrenic patients by hydrophilic interaction liquid chromatography with tandem mass spectrometry.

J Sep Sci 2015 Mar 27;38(5):780-7. Epub 2015 Jan 27.

Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.

A sensitive, reproducible, and rapid method was developed for the simultaneous determination of underivatized amino acids (aspartate, serine, glycine, alanine, methionine, leucine, tyrosine, and tryptophan) and neurotransmitters (glutamate and γ-aminobutyric acid) in plasma samples using hydrophilic interaction liquid chromatography coupled to triple quadrupole tandem mass spectrometry. The plasma concentrations of amino acids and neurotransmitters obtained from 35 schizophrenic patients in treatment with clozapine (27 patients) and olanzapine (eight patients) were compared with those obtained from 38 healthy volunteers to monitor the effectiveness of treatment. The chromatographic conditions separated ten target compounds within 3 min. This method presented linear ranges that varied from (lower limit of quantification: 9.7-13.3 nmol/mL) to (upper limit of quantification: 19.4-800 nmol/mL), intra- and interassay precision with coefficients of variation lower than 10%, and relative standard error values of the accuracy ranged from -2.1 to 9.9%. The proposed method appropriately determines amino acids and neurotransmitters in plasma from schizophrenic patients. Compared with the control group (healthy volunteers), the plasma levels of methionine in schizophrenic patients treated with olanzapine are statistically significantly higher. Moreover, schizophrenic patients treated with clozapine tend to have increased plasma levels of glutamate.
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http://dx.doi.org/10.1002/jssc.201400943DOI Listing
March 2015

Jacobsen catalyst as a cytochrome P450 biomimetic model for the metabolism of monensin A.

Biomed Res Int 2014 28;2014:152102. Epub 2014 May 28.

Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP, Brazil.

Monensin A is a commercially important natural product isolated from Streptomyces cinnamonensins that is primarily employed to treat coccidiosis. Monensin A selectively complexes and transports sodium cations across lipid membranes and displays a variety of biological properties. In this study, we evaluated the Jacobsen catalyst as a cytochrome P450 biomimetic model to investigate the oxidation of monensin A. Mass spectrometry analysis of the products from these model systems revealed the formation of two products: 3-O-demethyl monensin A and 12-hydroxy monensin A, which are the same ones found in in vivo models. Monensin A and products obtained in biomimetic model were tested in a mitochondrial toxicity model assessment and an antimicrobial bioassay against Staphylococcus aureus, S. aureus methicillin-resistant, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. Our results demonstrated the toxicological effects of monensin A in isolated rat liver mitochondria but not its products, showing that the metabolism of monensin A is a detoxification metabolism. In addition, the antimicrobial bioassay showed that monensin A and its products possessed activity against Gram-positive microorganisms but not for Gram-negative microorganisms. The results revealed the potential of application of this biomimetic chemical model in the synthesis of drug metabolites, providing metabolites for biological tests and other purposes.
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http://dx.doi.org/10.1155/2014/152102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4058456PMC
February 2015

Effects of the antimycobacterial compound 2-phenoxy-1-phenylethanone on rat hepatocytes and formation of metabolites.

Pharm Biol 2012 Oct 3;50(10):1317-25. Epub 2012 Aug 3.

Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, Brazil.

Context: Neolignans are usually dimers formed by oxidative coupling of allyl and propenyl phenols, and the neolignan analogue, 2-phenoxy-1-phenylethanone (LS-2) is a promising antimycobacterial compound showing very weak cytotoxicity in mammalian cells and lack of acute toxicity in murine models.

Objectives: To investigate the mechanism of action of LS-2 in rat hepatocytes by evaluating the activity levels of enzymes related to oxidation status and drug-metabolizing activity.

Materials And Methods: Hepatocytes were treated with LS-2 from 0.05 up to 1 mM, for 24 and 48 h, and reduced glutathione (GSH), lipid peroxidation and cytochrome P450 enzyme (CYP450) activity were assayed. A homologous series of phenoxazone ethers were used as substrates to measure the enzymatic profile. The biotransformation of LS-2 was studied in hepatocytes by gas chromatography-mass spectrometry (GC-MS) for detection and analysis of possible metabolites.

Results: Hepatocytes treated with LS-2 up to 1 mM for 24 or 48 h did not induce the formation of GSH and lipid peroxidation. O-Dealkylation activities of the isoenzymes CYP4501A1, CYP4501A2, CYP4502B1 and CYP4502B2 were also not detected in the hepatocytes treated with LS-2 for 24 or 48 h.

Discussion And Conclusion: The results indicate that LS-2 or its two detected metabolites, 2-phenoxy-1-phenylethanol and 2,4-(2-hydroxy-2-phenylethoxy)phenol, are not cytotoxic to rat hepatocytes. These compounds maintain a balance between the production of pro-oxidant agents and their respective antioxidant systems. The data show that enzymes related to oxidation status and drug-metabolizing activities are not involved in the mechanism of action of LS-2.
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http://dx.doi.org/10.3109/13880209.2012.674949DOI Listing
October 2012

Effect of a highly concentrated lipopeptide extract of Bacillus subtilis on fungal and bacterial cells.

Arch Microbiol 2008 Dec 25;190(6):611-22. Epub 2008 Jul 25.

Faculdade de Química, PUC-Campinas, C. Postal 317, Campinas, SP 13012-970, Brazil.

Lipopeptides produced by Bacillus subtilis are known for their high antifungal activity. The aim of this paper is to show that at high concentration they can damage the surface ultra-structure of bacterial cells. A lipopeptide extract containing iturin and surfactin (5 mg mL(-1)) was prepared after isolation from B. subtilis (strain OG) by solid phase extraction. Analysis by atomic force microscope (AFM) showed that upon evaporation, lipopeptides form large aggregates (0.1-0.2 microm(2)) on the substrates silicon and mica. When the same solution is incubated with fungi and bacteria and the system is allowed to evaporate, dramatic changes are observed on the cells. AFM micrographs show disintegration of the hyphae of Phomopsis phaseoli and the cell walls of Xanthomonas campestris and X. axonopodis. Collapses to fungal and bacterial cells may be a result of formation of pores triggered by micelles and lamellar structures, which are formed above the critical micelar concentration of lipopeptides. As observed for P. phaseoli, the process involves binding, solubilization, and formation of novel structures in which cell wall components are solubilized within lipopeptide vesicles. This is the first report presenting evidences that vesicles of uncharged and negatively charged lipopeptides can alter the morphology of gram-negative bacteria.
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http://dx.doi.org/10.1007/s00203-008-0409-zDOI Listing
December 2008
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