Eduardo Oliveira

Universidade Federal dos Vales do Jequitinhonha e Mucuri | UFVJM · Departamento de Farmácia

A particularly phenolic-rich fraction extracted from red wine from the São Francisco valley (Northeastern Brazil) was chemically characterized and its hypotensive and antioxidant effects on spontaneously hypertensive rats were studied both in vitro and in vivo. The liquid-liquid pH dependent fractionation scheme afforded a fraction with high conten...

In this study, Rumex Acetosa extracts were obtained from extraction techniques with supercritical fluid (SFE), Soxhlet and low pressure solvent extraction (LPSE). In the SFE, it was evaluated the effect of the process variables (temperature, solvent flow rate, pressure and cosolvent concentration) on the extraction kinetics, yield and extract solub...

Dalbergia ecastaphyllum (L.) Taub. is a shrubby of Tropical America and Africa. It is recognized as the main botanical source of red-propolis, and also by its uses in folk medicine. This work was performed by light and scanning electron microscopy in order to carry out an anatomical and histochemical study of leaves and stems of this species,to fin...

The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize po...

A bioassay-guided fractionation of two samples of Brazilian red propolis (from Igarassu, PE, Brazil, hereinafter propolis 1 and 2) was conducted in order to determine the components responsible for its antimicrobial activity, especially against Candida spp. Samples of both the crude powdered resin and the crude ethanolic extract of propolis from bo...

The aim of this study was to investigate the cytotoxic effect of new 1,4-naphthoquinone- 1,2,3-triazoles, named C2 to C8 triazole derivatives, towards human cancer cell lines. The effect on cell viability was assessed by MTT and propidium iodide assays. The cytotoxic effect of C2 and C3 in K562 and HL-60 cells were analyzed by flow cytometry, DNA f...

Cissampelos sympodialis Eichl. (Menispermaceae) is used in folk medicine for the treatment of respiratory conditions such as bronchitis and asthma. The aqueous fraction of the hydroalcoholic extract of its leaves has shown immunomodulatory, bronchodilator and anti-inflammatory activities. However, there is no data available on the pharmacognostic q...

Background Asthma is an inflammatory condition characterized by airway hyperresponsiveness and chronic inflammation. The resolution of inflammation is an essential process to treat this condition. In this study we investigated the effect of Allium cepa L. extract (AcE) and quercetin (Qt) on cytokine and on smooth muscle contraction in vitro and its...

Different studies have reported the promising pharmacological activities of yangambin, a lignan from Ocotea duckei Vattimo, mainly as an anti-leishmanial and antitumor compound. However, this lignan has demonstrated to be commonly isolated only as a mixture of diastereoisomers. In this regard, here it is described for the first time, the separation...

Background Cissampelos sympodialis Eichl. (Menispermaceae) is used in folk medicine for the treatment of respiratory conditions such as bronchitis and asthma. The aqueous fraction of the hydroalcoholic extract of its leaves has shown immunomodulatory, bronchodilator and anti-inflammatory activities. However, there is no data available on the pharma...

The paper is a review of the literature on the ethnobotanical, chemical and pharmacological aspects of the species Cissampelos sympodialis Eichler, Menispermaceae, in order to assess its potential for the treatment of asthma. The aqueous infusion from the leaves of this Brazilian plant is used in the traditional medicine for the treatment of respir...

des-7'-O-methylroraimine (compound 1) and epi-des-7'-O-methylroraimine (compound 2), two new isomeric bisbenzylisoquinoline alkaloids were isolated and characterized as a mixture from the rhizomes of Cissampelos sympodialis Eichl. The unambiguous structural elucidation of both isomers was performed with the aid of HR-ESI-MS, FT-IR, and NMR techniqu...

The leaf hydroalcoholic extract of Cissampelos sympodialis Eichl. (Menispermaceae) has shown promising activity in different animal models of asthma. Several alkaloids have been identified in the extract, including warifteine and methylwarifteine (bisbenzylisoquinoline), as well as milonine (morphinandienone). To develop and validate an analytical...

A limited number of studies with application of the Arrhenius equation have been reported to drugs and biopharmaceuticals in biological fluids at frozen temperatures. This paper describes stability studies of ampicillin and cephalexin in aqueous solution and human plasma applying the Arrhenius law for determination of adequate temperature and time...

Allergic asthma has emerged as an important public health problem of urban populations in developed countries. Very often herbal medicine is used to treat this widespread disease, due to the lack of efficacy and the important side effects related to the classical drugs in use. Along this line, Ocimum gratissimum (Og) is a plant widely used in Brazi...

The development and validation of a simple and accurate method by HPLC-UV to quantify meloxicam (MLX) in human plasma and its application to comparative bioavailability study between MLX formulation and manipulated meloxicam + prednisone + cyclobenzaprine + diacerein + hidroxychloroquine is described. MLX and the internal standard (piroxicam) were...

The aim of this study was to investigate the mechanisms underlying the vasorelaxant effect induced by the polyphenolic compounds found in red wine from Vale do São Francisco. In phenylephrine (10 μM) precontracted mesenteric artery rings, the red wine caused a concentration-dependent relaxation (maximum response to phenylephrine 10 μM = 87.5% ± 6.5...

Asthma is one of the most prevalent chronic diseases worldwide. Medicinal plants are historically used in its treatment. The plant Cissampelos sympodialis, known in Northeastern Brazil as "Jarrinha" or "Milona", is used to treat some inflammatory conditions, including asthma. The objective of this study was to evaluate the potential of Cissampelos...

The usefulness of pyrolysis coupled to gas chromatography/mass spectrometry (Py-GC/MS) to evaluate the identity and reproducibility of different brands and batches of commercially available samples of Cymbopogon citratus Stapf (sold as tea) was investigated. Samples of the vegetable material were extracted using hexane and the extract was pyrolysed...

The levels of total phenolics, resveratrol (cis- and trans-isomers), quercetin, monomeric anthocyanin and the antioxidant activity of monovarietal northeastern Brazilian wines were investigated. Antioxidant activities of wine samples were determined after extraction using ethyl acetate at different pH values, yielding three fractions for each sampl...

We describe the validation data of a simple but selective chromatographic method for determination of ampicillin in human plasma using liquid chromatography–diode array detector. Blank plasma free of drugs was transferred to eppendorf’s tubes and spiked with ampicillin stock solution to obtain quality control samples at 1.00, 2.50, 5.00, and 10.00...

We describe the validation data of a simple but selective chromatographic method for determination of ampicillin in human plasma using liquid chromatography-diode array detector. Blank plasma free of drugs was transferred to eppendorf's tubes and spiked with ampicillin stock solution to obtain quality control samples at 1.00, 2.50, 5.00, and 10.00...

The comparison of two methods based on online solid phase extraction-liquid chromatography with UV (SPE-LC-UV) or mass spectrometry detection (SPE-LC-MS/MS) for the simultaneous quantification of sulfamethoxazole (SMZ) and trimethoprim (TMP) is presented. The methods were validated and proved to be accurate. The analysis of standard samples for SMZ...

The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of norfloxacin (NFX) in human plasma and its application to a bioequivalence study between two norfloxacin formulations is described. NFX and the internal standard (cyprofloxacin) were extracted from plasma using liquid-liq...

The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of norfloxacin (NFX) in human plasma and its application to a bioequivalence study between two norfloxacin formulations is described. NFX and the internal standard (cyprofloxacin) were extracted from plasma using liquid-liq...

13 C NMR-HBBD and 13 C NMR- DEPT) and heteronuclear 2D NMR techniques ( 1 H- 1 H-COSY, 1 H- 1 H-NOESY, HSQC, HMBC), and HREIMS. The unambiguous assignments of 1 H and 13 C NMR data of derivatives 3-N,6-O- diacetyl-isojuripidine and 3-N-cinnamoyl-isojuripidine are described.

A method for the quantification of aflatoxins B1, G1, B2 and G2 in the medicinal herb Maytenus ilicifolia was developed and validated. The method used immunoaffinity columns for sample clean-up and HPLC with fluorescence detection without any derivatisation step. The method showed good inter-day accuracy (bias values in the range 4.5-10.7%) and pre...

The development and validation of a simple method for the simultaneous determination of ranitidine and metronidazole in human plasma is described. Plasma samples (250 microL) were deproteinized by precipitation with 60% perchloric acid, centrifuged and the supernatant directly injected into the HPLC. Separation was achieved in isocratic mode with a...

Isojuripidine was isolated from the aerial parts of Solanum astherophorum Mart. Its structure was determined using a combination of homo-(1D H-1 NMR, C-13 NMR-HBBD and C-13 NMR-DEPT) and heteronuclear 2D NMR techniques (H-1-H-1-COSY, H-1-H-1-NOESY, HSQC, HMBC), and HREIMS. The unambiguous assignments of H-1 and C-13 NMR data of derivatives 3-N,6-O-...

This review covers the applications of mass spectrometry with sample introduction in the liquid phase to the analysis of the oxidation products of DNA, proteins and lipids in vitro and in vivo. The analysis of antioxidant xenobiotics in biological systems is also covered. The review covers the period 1997–late 2002. The most commonly used mass spec...

This work developed a methodology that can potentially be applied to the quality control of cimetidine drug substance and its tablets. The kT obtained at different temperatures (200, 190, 180, 170 and 160C) were determined by isothermal thermogravimetric method using the classical Arrhenius equations. The dissolution profiles were obtained using US...

TG and DSC data were used to determine the thermal parameters of metronidazole drug and tablets. Three tablets A, B and C were analysed. The TG curves of metronidazole drug and tablets A and B displayed five and C four thermal decomposition processes, respectively. Analysis of the DSC data pointed to chemical interactions between metronidazole drug...

The use of blood spot collection cards is a simple way to obtain specimens for analysis of drugs with a narrow therapeutic window. We describe the development and validation of a microanalytical technique for the determination of paracetamol and its glucuronide and sulphate metabolites from blood spots. The method is based on reversed phase high-pe...

1. The metabolism of the flavonoids quercetin and kaempferol by rat hepatocytes was investigated using liquid chromatography coupled with electrospray mass spectrometry (LC-ESI MS). Quercetin and kaempferol were extensively metabolized (98.8 +/- 0.1% and 81.0 +/- 5.1% respectively, n = 4), with four glucuronides of quercetin and two of kaempferol b...

Although a great number of papers demonstrate an association between high intake of fruits and vegetables and reduced risk of certain types of cancer, the epidemiological evidence is not conclusive. The identification and quantification of specific dietary anticancer compounds in plasma, urine and tissues is an important aspect of this research. We...

The coumarin scopoletin was isolated in a pure form from the roots of Brunfelsia hopeana Benth. (Solanaceae). In isolated rat aortic rings, scopoletin (26-520 microM) inhibited to approximately the same extent the contractions induced by a variety of substances, including phenylephrine, potassium chloride, serotonin and PGF(2) (alpha). The effect o...

Monitoring of drugs (such as theophylline) with a narrow therapeutic window could be simplified if patients were able to submit blood spots for analysis. This could reduce clinic attendance for venous blood sampling and save staff time. A rapid sensitive method utilizing liquid chromatography-mass spectrometry has been developed to determine the am...

The application of liquid chromatography-mass spectrometry (LC/MS) to the study of metabolism of drugs and other xenobiotics is reviewed. Original research papers covering the period from 1998 to early 2000 and concerning the use of LC/MS in the study of xenobiotic metabolism in humans and other mammalian species are reviewed. LC/MS interfaces, sam...

The application of liquid chromatography–mass spectrometry (LC/MS) to the study of metabolism of drugs and other xenobiotics is reviewed. Original research papers covering the period from 1998 to early 2000 and concerning the use of LC/MS in the study of xenobiotic metabolism in humans and other mammalian species are reviewed. LC/MS interfaces, sam...

Flavonoids are important polyphenolic substances with widespread occurrence in plants and therefore in the human diet. Although considerable work has been done on the pharmacology of flavonoids, the understanding of their metabolism is still incomplete. In this work, the in vitro glucuronidation of the common dietary flavonoids quercetin and kaempf...

A method was developed for the quantification of the flavonoids quercetin and kaempferol in human urine using a solid-phase extraction procedure followed by gas chromatography-mass spectrometry. Deuterated internal standards of the analytes were spiked into the samples prior to extraction. The limit of detection of the method was ca. 10 pg on colum...

The identity and structures of the three main tertiary indole alkaloids of Strychnos atlantica were confirmed and verified by high field nuclear magnetic resonance (NMR) spectroscopy. Complete 1H and 13C NMR spectral assignments were obtained. © 1997 John Wiley & Sons, Ltd.

Normacusine B, a tertiary indole alkaloid, was isolated in pure form from the root bark of Strychnos atlantica Krukoff & Barneby. In conscious unrestrained rats, normacusine B (1 mg/kg) decreased the mean arterial blood pressure (27.6 ± 8.4 mmHg, n = 6), followed by a significant increase in heart rate (115.0 ± 12.7 bpm, n = 6). The alkaloid failed...