Hildegardo S. França

Mikania glomerata Spreng: desenvolvimento de um produto fitoterápico

Although the pharmacological activity of Mikania glomerata Spreng. has been well known for a long time, there are a few studies concerning the elaboration of phytopharmaceutical products that assure an uniform preparation, effective doses and stability. In this work, tests with the objective of the optimization of the extraction process were performed; treatment of the plant drug for preparation of tinctures; determination of the adequate form of storage and the optimization of the preparation of the pharmaceutical form (syrup).

Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis

Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.

In Vitro Antiophidian Mechanisms of Hypericum brasiliense Choisy Standardized Extract: Quercetin-Dependent Neuroprotection

The neuroprotection induced by Hypericum brasiliense Choisy extract (HBE) and its main active polyphenol compound quercetin, against Crotalus durissus terrificus (Cdt) venom and crotoxin and crotamine, was enquired at both central and peripheral mammal nervous system. Cdt venom (10 μg/mL) or crotoxin (1 μg/mL) incubated at mouse phrenic nerve-diaphragm preparation (PND) induced an irreversible and complete neuromuscular blockade, respectively. Crotamine (1 μg/mL) only induced an increase of muscle strength at PND preparations. At mouse brain slices, Cdt venom (1, 5, and 10 μg/mL) decreased cell viability. HBE (100 μg/mL) inhibited significantly the facilitatory action of crotamine (1 μg/mL) and was partially active against the neuromuscular blockade of crotoxin (1 μg/mL) (data not shown). Quercetin (10 μg/mL) mimicked the neuromuscular protection of HBE (100 μg/mL), by inhibiting almost completely the neurotoxic effect induced by crotoxin (1 μg/mL) and crotamine (1 μg/mL). HBE (100 μg/mL) and quercetin (10 μg/mL) also increased cell viability in mice brain slices. Quercetin (10 μg/mL) was more effective than HBE (100 μg/mL) in counteracting the cell lysis induced by Cdt venom (1 and 10 μg/mL, resp.). These results and a further phytochemical and toxicological investigations could open new perspectives towards therapeutic use of Hypericum brasiliense standardized extract and quercetin, especially to counteract the neurotoxic effect induced by snake neurotoxic venoms.

Documentoscopy by atomic force microscopy (AFM) coupled with Raman microspectroscopy: applications in banknote and driver license analyses

Document examination to determine document authenticity is an important field in forensic science. Methods of counterfeiting have become sophisticated, so the development of informative and effective tools for questioned document examination becomes necessary and challenging. Atomic force microscopy (AFM) and Raman microspectroscopy have been shown to be advantageous, allowing the comparison of inks, the sequencing of crossing lines, and providing physicochemical information about the nature of the paper and of the ink deposition mechanism. Herein, AFM and Raman techniques are explored for the analysis of both authentic and counterfeit Brazilian driver licenses, and national and international banknotes. For AFM results, parameters, such as roughness and topographic profiles of the chalcographic region of banknotes and Brazilian driver licenses, are sufficient to visually discriminate between authentic and counterfeit documents. However, statistical analysis using the Students t-test showed that the asymmetry (SSK) values obtained from series numbers and micro-letter regions identified the counterfeiting. Compared to the topographic profile obtained for homemade banknotes produced by different printers (inkjet and LaserJet), the AFM technique indicated that the paper used to counterfeit the Brazilian driver license and the real banknote was an “office” type with inkjet printing. For Raman spectroscopy results, bands of phthalocyanine, and diarylide (diazo) pigments, and carbon black were identified in authentic documents, whereas for counterfeit documents, only a high fluorescence was observed. The obtained data were reproducible via the video spectral comparison (VSC) technique, typically used by forensic police laboratories.

Conformational analysis of phloroglucinols from Hypericum brasiliense by using X-ray diffraction and molecular modeling.

In this work we intend to verify the applicability of a computational methodology to predict structural features of organic compounds with biological activity. We selected three phloroglucinols and compared their calculated conformational data with their X-ray crystallographic structure. The results showed that conformations obtained by conformational analysis with the AM1 method followed by geometry optimization by using the DFT B3LYP/6-31 G(d,p) basis set are in very good agreement with X-ray data, indicating that the methodology employed here seems to be a very useful tool in order to predict the conformational preference for this class of compounds.

Estudo de alcalóides de Pilocarpus pennatifolius Lemaire

O genero Pilocarpus da Familia das Rutaceas compreende 13 especies neotropicais espalhadas na regiao situada entre os tropicos de câncer e capricornio. No Brasil sao encontradas 9 especies, que recebem designacao geral de jaborandi1, fonte industrial de pilocarpina, utilizada no tratamento de glaucoma. A pilocarpina e produzida no pais, em escala industrial, a partir do P. microphyllus Stapf, nativa do Estado do Maranhao. Umas das especies botanicamente proxima a P. microphyllus e a P. pennatifolius Lem. O metodo empregado de analise foi segundo a Farmacopeia Suissa IV Ed. (modificado), que avalia o teor de alcaloides totais, expressando o resultado em pilocarpina. A evidenciacao dos alcaloides secundarios se deu atraves de cromatografia de camada fina (CCF). A analise dos resultados obtidos indicam que dificilmente a especie constituira um substituto para materia-prima de extracao de pilocarpina, visto que o teor da mesma em P. microphyllus chega a ultrapassar 1,0 %. A presenca de diversas manchas na CCF recomenda o isolamento e identificacao dos alcaloides secundarios para a complementacao da informacao bibliografica.

Secondary metabolites from leaves of Manilkara subsericea (Mart.) Dubard

Background: Manilkara subsericea (Sapotaceae) is a species widely spread in the sandbanks of Restinga de Jurubatiba National Park (Rio de Janeiro, Brazil). It is commonly known as “maçaranduba”, “maçarandubinha” and “guracica”, being used in this locality as food, and timber. However, M. subsericea remains almost unexplored regarding its chemical constituents, including secondary metabolites from the leaves. Objective: Identify the chemical constituents from the leaves of M. subsericea. Materials and Methods: Leaves were macerated with ethanol (96% v/v), and dried crude ethanolic extract was sequentially washed with the organic solvents in order to obtain an ethyl acetate fraction. Substances from this fraction were identified by different techniques, such as negative-ion electrospray ionization Fourier and 1H and 13C nuclear magnetic resonance (NMR). Fresh leaves from M. subsericea were also submitted to hydrodistillation in order to obtain volatile substances, which were identified by gas chromatograph coupled to mass spectrometer. Results: NMR1H and 13C spectra allowed for the identification of the compounds myricetin, quercetin, and kaempferol from the ethyl acetate fraction. The negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry mass spectrum also revealed the presence in this fraction of a polyhydroxytriterpene acid (pomolic acid), and some flavonoids, such as quercitrin, and myricitrin. In all 34 volatile compounds were identified by gas chromatography-mass spectrometry, including monoterpenes, sesquiterpenes, and long chain hydrocarbons. Conclusion: This study describes the first reports concerning the phytochemical information about leaves from M. subsericea. SUMMARY Manilkara subsericea fruits proved to be a rich source of triterpenes. However, no phytochemical studies were carried out with leaves. Thus, we described identification of volatile substances from its essential oils, in addition to non-reported triterpene and flavonoids from this species.