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Dive into the research topics where Renata Pereira Limberger is active.

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Featured researches published by Renata Pereira Limberger.


Food and Chemical Toxicology | 2008

Concentrations of p-synephrine in fruits and leaves of Citrus species (Rutaceae) and the acute toxicity testing of Citrus aurantium extract and p-synephrine.

Marcelo Dutra Arbo; Elisa Rupp Larentis; V.M. Linck; Ana Lúcia Aboy; A.L. Pimentel; A.T. Henriques; Eliane Dallegrave; Solange Cristina Garcia; Mirna Bainy Leal; Renata Pereira Limberger

Dietary supplements containing bitter orange unripe fruit extract/p-synephrine are consumed worldwide for lose weight. This study were conducted to determine the concentration of p-synephrine in unripe fruits and leaves from Citrus aurantium Lin, C. sinensis Osbeck, C. deliciosa Ten, C. limon Burm and C. limonia Osbeck, collected in Southern Brazil, and to evaluate the acute toxicity of C. aurantium extract and p-synephrine. A high performance liquid chromatographic method with diode array detector (HPLC-DAD) was optimized and validated for determination of p-synephrine. The results indicate that all of analyzed samples present p-synephrine in amounts that range from 0.012% to 0.099% in the unripe fruits and 0.029 to 0.438% in the leaves. Acute oral administration of C. aurantium extracts (2.5% p-synephrine, 300-5,000 mg/kg) in mice produced reduction of locomotor activity, p-synephrine (150-2,000 mg/kg) produced piloerection, gasping, salivation, exophtalmia and reduction in locomotor activity, which was confirmed in spontaneous locomotor activity test. All the effects were reversible and persisted for 3-4h. The toxic effects observed seem to be related with adrenergic stimulation and should alert for possible side effects of p-synephrine and C. aurantium.


Regulatory Toxicology and Pharmacology | 2009

Subchronic toxicity of Citrus aurantium L. (Rutaceae) extract and p-synephrine in mice

Marcelo Dutra Arbo; Gabriela Cristina Schmitt; Mariana Fagundes Limberger; Mariele F. Charão; Ângela M. Moro; Gianine Ribeiro; Eliane Dallegrave; Solange Cristina Garcia; Mirna Bainy Leal; Renata Pereira Limberger

Extracts of Citrus aurantium L. (Rutaceae) unripe fruits have gained popularity for the treatment of obesity. Due to the wide use of C. aurantium/p-synephrine-containing products, this research was undertaken to evaluate its subchronic toxicity in mice and their actions in oxidative stress biomarkers. Groups of 9-10 mice received for 28 consecutive days a commercial C. aurantium dried extract (containing 7.5% p-synephrine) 400, 2000 or 4000 mg/kg and p-synephrine 30 or 300 mg/kg by oral gavage. There was a reduction in body weight gain of animals treated with both doses of p-synephrine. Organs relative weight, biochemical and hematological parameters were not altered in all treated mice. There was an increase in reduced glutathione (GSH) concentration in groups treated with C. aurantium 4000 mg/kg and p-synephrine 30 and 300 mg/kg. In glutathione peroxidase (GPx), there were an inhibition of the activity in C. aurantium 400 and 2000 mg/kg and p-synephrine 30 and 300 mg/kg treated animals, respectively, and was no alteration in malondialdehyde (MDA) levels. Thus, the results indicate a low subchronic toxicity of the tested materials in mice and a possible alteration in the oxidative metabolism. However, further tests are required to better elucidate the effects of these compounds in the antioxidant system.


Química Nova | 2004

Óleos voláteis de espécies de Myrcia nativas do Rio Grande do Sul

Renata Pereira Limberger; Marcos Sobral; Amelia Teresinha Henriques; Chantal Menut; J. M. Bessière

Essential oils from M. richardiana, M. arborescens, M. selloi, M. oligantha, M. rostrata, M. lajeana, M. obtecta, M. pubipetala and M. hatschbachii were obtained by hydrodistillation and analyzed by GC and GC/MS. Sixty-seven compounds have been identified ranging from 90-99% of the oil contents. All analyzed species were rich in cyclic sesquiterpenes (66-99%), mainly those from the cadinane, caryophyllane and germacrane cyclization pathway, among them b-caryophyllene, germacrene D, bicyclogermacrene, d-cadinene, spathulenol, caryophyllene oxide, globulol and a-cadinol. The acyclic sesquiterpene series was well represented by M. lajeana (32.1%), with 25,3% of (E)-nerolidyl acetate.


Forensic Science International | 2013

Counterfeit Cialis and Viagra fingerprinting by ATR-FTIR spectroscopy with chemometry: Can the same pharmaceutical powder mixture be used to falsify two medicines?

Rafael S. Ortiz; Kristiane de Cássia Mariotti; Bruna Fank; Renata Pereira Limberger; Michel J. Anzanello; Paulo Mayorga

This paper proposes a direct and efficient method to discriminate between counterfeit and authentic Cialis and Viagra samples by combining attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy with multivariate techniques. The chemical profile of 53 commercial samples (Viagra(®), Cialis(®)) and 104 counterfeit samples (Viagra and Cialis) from distinct seizures were obtained from ATR-FTIR data derived from 10mg of crushed core tablets. Principal component analysis (PCA) technique was employed to classify samples based on the fingerprint region mid-infrared spectra (1800-525 cm(-1)) using OMNIC v.7.2 software; PCA enabled categorizing samples in groups with different chemical profiles, successfully distinguishing between authentic and counterfeits samples in forensic routine. The existence of active pharmaceutical ingredients (API) and technological adjuvant others than specified on the medicine package were also detected in counterfeit samples. In addition, we applied the similarity match (SM) method to demonstrate that a mixture of pharmaceutical powders deriving from a common origin may have been used to manufacture both counterfeit Cialis and Viagra tablets from distinct seizures.


Journal of Essential Oil Research | 2001

Chemical Composition of Essential Oils from SomeCampomanesiaSpecies (Myrtaceae)

Renata Pereira Limberger; Miriam Anders Apel; Marcos Sobral; Paulo Roberto H. Moreno; Amelia Teresinha Henriques; Chantal Menut

Abstract The chemical composition of leaf oils from Campomanesia aurea, C. guazumifolia, C. rhombea and C. xanthocarpa (Myrtaceae) were analyzed by GC and GC/MS. Sixty-two compounds have been identified ranging from 94–99% of the oil contents. Our results showed that all analyzed species were rich in sesquiterpenes, among them spathulenol (27.7%) and !b-caryophyllene oxide (29.0%) in C. guazumifolia; bicyclogermacrene (13.6%) and globulol (10.8%) in C. rhombea; and (E)-nerolidol (28.8%) in C. xanthocarpa. The monoterpene fraction was well represented in C. aurea (40.3%), with predominance of the α-pinene (16.5%) and myrcene (11.5%), besides C. rhombea and C. xanthocarpa that showed an important amount of linalool (9.7% and 17.2%, respectively).


Journal of Pharmaceutical and Biomedical Analysis | 2012

Fingerprinting of sildenafil citrate and tadalafil tablets in pharmaceutical formulations via X-ray fluorescence (XRF) spectrometry.

Rafael S. Ortiz; Kristiane de Cássia Mariotti; Nicolas V. Schwab; Guilherme P. Sabin; Werickson Fortunato de Carvalho Rocha; Eustáquio V.R. Castro; Renata Pereira Limberger; Paulo Mayorga; Maria Izabel Maretti Silveira Bueno; Wanderson Romão

The production of counterfeited drugs is a criminal problem that carries serious risks to public health in the worldwide. In Brazil, Viagra and Cialis are the most counterfeit medicines, being used to inhibit the phosphodiesterase type 5 (PDE-5), treating thus, problems related to erectile dysfunction. X-ray fluorescence (XRF) is a suitable technique to control the quality of new pharmaceutical formulations and distinguish between authentic and counterfeit tablets. XRF has advantageous features like multielemental capability, good detectivity, high precision, short analysis times, and is nondestructive, which makes it suitable to be extended to a great variety of samples. In this work, the inorganic fingerprinting chemical of forty-one commercial samples (Viagra, Cialis, Lazar, Libiden, Maxfil, Plenovit, Potent 75, Rigix, V-50, Vimax and Pramil) and fifty-six counterfeit samples (Viagra and Cialis) were obtained from XRF data. XRF presented an excellent analytical methodology for semi-quantitative determination of active ingredient (in case of sildenafil citrate that presents S in its structure) and excipients such as calcium phosphate, titanium oxide and iron oxide (P, Ca, Ti and Fe). The matrix data were allied to chemometric methods (Principal Component Analysis and Hierarchical Cluster Analysis) to classify the tablets investigated between authentic and counterfeit, grouping the samples into of seven groups: A, B, C, D and E (counterfeit group) and F and G (authentic group).


Forensic Science International | 2012

Prescription and illicit psychoactive drugs in oral fluid—LC–MS/MS method development and analysis of samples from Brazilian drivers

Ivomar Zancanaro; Renata Pereira Limberger; Paula O. Bohel; Maíra Kerpel dos Santos; Raquel Brandini De Boni; Flavio Pechansky; Eloisa Dutra Caldas

This study is part of a larger project designed to investigate the prevalence of psychoactive drug (PAD) use among Brazilian drivers. In this paper we describe the development and validation of an analytical method to analyze 32 prescription and illicit PADs (amphetamines, benzodiazepines, cocaine, cannabis, opioids, ketamine and m-CPP) and metabolites in oral fluid samples collected with a Quantisal™ device. Samples were extracted with ethyl acetate:hexane and analyzed by LC-MS/MS. Instrumental LOD ranged from 0.26 to 0.65 ng/mL. Mean procedural recoveries at 1.3 ng/mL (LLOQ) ranged from 50% to 120% for 24 compounds. Recoveries were concentration independent, with the exception of femproporex, heroin and ecgonine methyl-ester (EME) for which the recovery decreased significantly at higher levels (13 and 52 ng/mL). RSD was <20% for all compounds at all spiking levels. Ion suppression due to the matrix was <20% for most compounds, and higher than 60% for EME and diethylpropion. Analysis was performed against a in-matrix standard curve. About 10% of the 2235 oral fluid samples collected from drivers on Brazilian Federal highways were positive (≥LOD) for at least one analyte investigated. Alone or in combination with other drugs, cocaine/metabolites were the analytes most detected in the samples (129; 5.8%), followed by amphetamines/metabolite (69; 3.1%), benzodiazepines (28; 1.2%), cannabinoids (23; 1.1%) and opioids (8; 0.4%). Detection of at least two PADs from different classes accounted for 9.3% of the 236 positive samples. Cocaine was found at higher levels in the samples (up to 1165 ng/mL). Preventive measures aimed at reducing the use of PADs by drivers in Brazil will certainly contribute to decrease the countrys highway death rates.


Nephrology Dialysis Transplantation | 2009

The plasma retinol levels as pro-oxidant/oxidant agents in haemodialysis patients

Miguel Roehrs; Juliana Valentini; Rachel Picada Bulcão; José Cláudio Fonseca Moreira; Hanz Biesalski; Renata Pereira Limberger; Tilman Grune; Solange Cristina Garcia

BACKGROUND Oxidative stress is a process involved in haemodialysis-related pathologies such as cerebrovascular diseases. Retinol is the major circulating form of vitamin A and it is elevated in haemodialysis (HD) patients. It is known that these patients present anaemia that is not totally responsive to erythropoietin. The aim of this study was to evaluate the influence of plasma retinol levels on oxidative stress biomarkers, especially on delta-aminolevulinate dehydratase. METHODS Plasma retinol and malondialdehyde (MDA) levels were quantified by HPLC-UV/VIS; blood activities of catalase (CAT), superoxide dismutase (SOD) and delta-aminolevulinate dehydratase (ALA-D) were analysed by spectrophotometric methods, in HD patients (n = 29) and healthy subjects (n = 20). RESULTS The MDA and retinol levels, SOD and CAT activities were significantly increased in HD patients. ALA-D activity was significantly decreased. Retinol levels were correlated with MDA levels (r = 0.68), CAT (r = 0.39), SOD (r = 0.40) and ALA-D (r = -0.55). A partial correlation between retinol levels with ALA-D (r = 0.43), SOD (r = 0.30) and CAT (r = 0.36) activity was found, utilizing MDA levels as co-variable. CONCLUSION Higher retinol levels may be associated with the increase of SOD and CAT activities, but this increase was not sufficient to prevent the lipid peroxidation and ALA-D thiolic group oxidation. In this manner, our results could suggest that high retinol levels contribute as an additional factor to the oxidative tissue damage.


Biochemical Systematics and Ecology | 2001

Alkaloids of Erythroxylum (Erythroxylaceae) species from Southern Brazil

Jose Angelo Silveira Zuanazzi; Valéria Tremea; Renata Pereira Limberger; Marcos Sobral; Amelia Teresinha Henriques

A new alkaloid identified as 3beta,6beta-ditigloyloxynortropane as 3beta,7beta-ditigloyloxynortropane, 4-hydroxyhygrinic acid, methylecgonidine and tropacocaine have been isolated from the leaves of Erythroxylum argentinum. The new structure was established by means of spectroscopic techniques. Four other species E. deciduum, E. microphyllum, E. pelleterianum and E. cuneifolium collected in the state of Rio Grande do Sul were screened for methylecgonidine and tropacocaine by CG/MS. Two of these plants contain tropacocaine and two contain methylecgonidine. GC/MS analysis of all 5 species for cocaine proved fruitless. The chemotaxonomic significance of these results is discussed.


Scientia Agricola | 2007

Essential oil composition of fruit colour varieties of Eugenia brasiliensis Lam.

Paulo Roberto H. Moreno; Marcos Enoque Leite Lima; Marcos Sobral; Maria Claudia Marx Young; Inês Cordeiro; Miriam A. Apel; Renata Pereira Limberger; Amelia Teresinha Henriques

Eugenia brasiliensis Lam. is a variable species concerning fruit colour, with three recognized varieties. However, the definition of varieties is not easy for Myrtaceae species and not widely accepted. Two fruit colour varieties (purple and yellow) of E. brasiliensis had their essential oil composition analysed in order to give support to the existence of varieties for this species. Although, the major components in the leaf oil are the same monoterpenes for both varieties, α-pinene, β-pinene and 1,8-cineol, the purple fruit variety accumulates more oxygenated sesquiterpenes (33.9%) than the one with yellow fruits (3.8%). The major differences occurred in purple fruits that present as major components caryophyllene oxide (22.2%) and α-cadinol (10.4%), not found in the leaf oil, and the yellow fruit oil presented a similar composition as observed for the leaves. These fruit colour varieties of E. brasilensis can be considered as two distinct chemotypes, since the sesquiterpene pathway is more operant in the purple variety than in the yellow one, in which monoterpenes are mainly accumulated.

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Amelia Teresinha Henriques

Universidade Federal do Rio Grande do Sul

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Kristiane de Cássia Mariotti

Universidade Federal do Rio Grande do Sul

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Marcos Sobral

Universidade Federal do Rio Grande do Sul

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Rafael S. Ortiz

Universidade Federal do Rio Grande do Sul

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Pedro Eduardo Fröehlich

Universidade Federal do Rio Grande do Sul

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Flavio Pechansky

Universidade Federal do Rio Grande do Sul

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Miriam Anders Apel

Universidade Federal do Rio Grande do Sul

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Bruna Tassi Borille

Universidade Federal do Rio Grande do Sul

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Mirna Bainy Leal

Universidade Federal do Rio Grande do Sul

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