Paulo R. Ribeiro

A new biphenyl and antimicrobial activity of extracts and compounds from Clusia burlemarxii

Phytochemical investigation on Clusia burlemarxii (Clusiaceae) led to isolation and identification of nine compounds. Were isolated from leaves 3-O-α-L- rhamnopyranosylquercetin, 3-O-α-L-rhamnopyranosylkaempferol, 4-hydroxy-5,5-dimethyldihydrofuran-2-one, 2Z-δ-tocotrienoloic acid and friedelin and were isolated from trunk betulinic acid, protocatechuic acid, lyoniresinol, and a new biphenyl 2,2-dimethyl-3,5-dihydroxy-7-(4-hydroxyphenyl)chromane. The structures were determined by ¹H, ¹³C-NMR, DEPT, HMBC, HMQC, HRESIMS. The Minimal Inhibitory Concentration against Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Escherichia coli, Salmonella choleraesuis, Pseudomonas aeruginosa, Aspergillus niger and Cladosporium cladosporioides was also determined. Extracts and compounds showed significant activity against tested Gram-positive bacteria, none activity against tested Gram-negative bacteria and fungi.

Chapter 10 – Bioactive Natural Products as Potential Candidates to Control Aedes aegypti, the Vector of Dengue

This review deals with the description of bioactive secondary metabolites produced by the living organisms, including plants, fungi, bacteria (actinomycetes and cyanobacteria) and lichens which have activity against the mosquito Aedes aegypti, the vector responsible for dengue and yellow fever. The insecticidal activities of these compounds are discussed herein, and their mode of action and structure–activity relationships are presented when appropriate. Control agents (fungi, bacteria, and other organisms) are briefly commented since they can also be a rich source of bioactive compounds. It describes 319 compounds from plants, 25 from fungi, 27 from bacteria (including actinomycetes and cyanobacteria), and 7 from lichen and cites 264 references. Covering: up to February 2011.

Furfural - da biomassa ao laboratório de química orgânica

The goal of this manuscript is provide to students of Chemistry and related areas an alternative experiment in which they can obtain a compound and learn to observe and interpret properties and predict organic structure by obtaining furfural from biomass. Furfural is an organic compound, obtained through acid hydrolysis of pentosans, commonly used in the chemical and pharmaceutical industries. Students are guided to get furfural through extractive procedures and chemical reactions adapted to semi-micro laboratory scale. Characterization of furfural was done by chemical tests and physical properties. Identification was accomplished by a series of spectroscopic and spectrometric techniques.

Th17 immune responses in Brazilian dyslipidemic patients with atherosclerosis

&NA; Lymphocytes, macrophages, and immunological mediators are critical in atherogenesis, but Th17 cells are still little studied. We investigated blood lymphocyte profiles, cytometric changes in blood Th17 cells, and production of Th17‐associated cytokines by peripheral blood mononuclear cells (PBMCs) stimulated with phytohemagglutinin (PHA) in dyslipidemic patients. Forty‐nine Brazilian dyslipidemic patients, including 14 with negative coronary angiograms (CAs) and 35 with positive CAs (atherosclerosis), were classified into groups G1 and G2, respectively, and 27 healthy individuals without dyslipidemia were included in the control group (HI). In all participants, lipid profiles, CVD risk factors, atherogenic risk indexes, cytometry of blood T lymphocytes (CD4+ T, CD8+ T, and Th17 cells), and Th17 cytokine production were determined. Production of interleukin (IL)‐17A, IL‐17F, IL‐21, and IL‐22 was measured in culture supernatants of PHA‐stimulated PBMCs. Patients with atherosclerosis exhibited low levels of high‐density lipoprotein cholesterol and apolipoprotein A and showed increased atherogenic risk indexes and a higher frequency of prior acute myocardial infarction (AMI). CD8+ T‐cell counts were lower in patients with previous AMI and higher in dyslipidemic obese individuals. Th17 cell frequency was increased in dyslipidemic women with atherosclerosis. PBMCs from patients with atherosclerosis produced less IL‐17A and IL‐21, but more IL‐22. IL‐17F production was unaltered. In summary, cytometric changes in CD8+ T and Th17 lymphocytes and altered production of Th17‐associated cytokines were observed in these individuals and were related to endocrine factors, obesity, and AMI. The practical implications of these findings need to be investigated in future studies.

Amburana cearensis seed extract protects brain mitochondria from oxidative stress and cerebellar cells from excitotoxicity induced by glutamate

ETHNOPHARMACOLOGICAL RELEVANCE Amburana cearensis (Allemao) A.C.Sm. is a medicinal plant of the Brazilian Caatinga reported to present antioxidant and anti-inflammatory activity. This study aimed to evaluate the neuroprotective effect of the extracts obtained from the seeds of A. cearensis in primary cultures of cerebellar cells subjected to excitotoxicity induced by glutamate and brain mitochondria submitted to oxidative stress. MATERIALS and methods: Primary cultures of cerebellar cells were treated with the ethanol (ETAC), hexane (EHAC), dichloromethane (EDAC) and ethyl acetate (EAAC) extracts of the seeds of A.cearensis and subjected to excitotoxicity induced by glutamate (10µM). Mitochondria isolated from rat brains were submitted to oxidative stress and treated with ETAC. RESULTS Only the EHAC extract reduced cell viability by 30% after 72h of treatment. Morphological analyses by Immunofluorescence showed positive staining for glutamine synthetase, β-III tubulin, GFAP and IBA1 similar to control cultures, indicating a better preservation of astrocytes, neurons and microglia, after excitotoxic damage induced by glutamate in cerebellar cultures treated with the extracts. The ETAC extract also protected mitochondria isolated from rat brains from oxidative stress, reducing the swelling, dissipation of the membrane potential, ROS production and calcium influx. CONCLUSION Thus, this study suggests that the seed extracts from A. Cearensis exhibit neuroprotective potential against oxidative stress and excitotoxicity induced by glutamate and can be considered a potential therapeutic agent in the treatment of neurodegenerative diseases.

Evaluation of the hepatotoxicity of Abarema cochliacarpos extracts in mice Mus musculus

Abarema cochliacarpos (Gomes) Barneby & J.W. Grimes, Fabaceae, is a native species of Brazil popularly known as “barbatimao”, frequently found along the north coast of the state of Bahia. Local communities make an infusion from its stem bark, which is used to treat several diseases. This study aimed to evaluate the hepatotoxicity of A. cochliacarpos extracts in mice Mus musculus. The bark infusion and hydroalcoholic extract were administered nasogastrically into two groups of eight animals (four male and four female each). After 45 days all mice were killed and the livers were collected for further histological analysis. Hepatic steatosis, congestion of the hepatic vessels and presence of macrophages and lymphocytes infi ltrates in the liver, were observed in both group of animals, additionally animals that received the stem bark infusion presented an accumulation of pigments. None of the animals belonging to the negative control group showed any of the symptoms described above. In conclusion, the hydroalcoholic extract and infusion of A. cochliacarpos stem bark were proven to cause intoxication in mice. The hepatotoxicity of the infusion was more aggressive in females. Further studies are necessary to isolate compounds responsible for the toxic characteristics of A. cochliacarpos.