Characterization of principal nutritional components of Brazilian oil palm (Eliaes guineensis) fruits.

In spite of the fact that most of the members of Palmaceae contain high concentrations of oil, its potential as a source of oil and protein for human consumption has not been exploited. The pulp and kernels of the Eliaes guineensis palm fruits grown in the Northeast region of Brazil were analyzed only for their proximate composition. The lipid content of the dried pulp and kernels was 73.2% and 32.6%, respectively. Hexane extracted oils from the pulp and kernels yielded similar refractive indices, specific gravity but different peroxide, acid, iodine and saponification values. Gas chromatographic analysis revealed the presence of 24 and 18 fatty acids in pulp and kernel oils, respectively. The principal saturated acid of the pulp oil was palmitic acid (36.9% of the total), and lauric acid (53.3%) for kernel oil. Oleic acid was the predominant monounsaturated fatty acid in both the oils though its concentration in the pulp and kernel oils was 45.29% and 5.5%, respectively. In relation to the essential amino acids, pulp proteins presented a better profile than the kernel proteins. In comparison to the FAO reference protein, the pulp proteins were deficient in methionine, lysine and threonine (16.8%, 51.6% and 93.5% of FAO reference protein) but contained leucine, valine, isoleucine and phenylalanine in optimal concentrations. With exception to phenylalanine and valine (102.2% and 111.4% of reference protein, respectively), the kernel proteins were deficient in all other essential amino acids. The oils from this palm can be used as culinary oil and in margarine manufacture, while pulp could be a supplement for essential amino acids leucine, isoleucine, phenylalanine and valine with other protein sources that are deficient in these amino acids.

Interesse dos estudantes de Farmácia e Biologia por plantas medicinais e fitoterapia

Este trabalho descreve os resultados obtidos em um levantamento realizado com 262 estudantes dos cursos de Farmácia e Biologia, de várias partes do Brasil, sobre o tema Plantas Medicinais e Fitoterapia. Foram aplicados questionários com questões relativas aos dados pessoais de cada estudante e questões relacionadas a temas, como por exemplo: a) por que o estudante se interessava por Plantas Medicinais e Fitoterapia? e b) estudante deveria citar cinco plantas que mais conhecia e/ou utilizava. Os resultados da pesquisa demonstraram que os estudantes de Farmácia e Biologia reconhecem a importância das Plantas Medicinais e da Fitoterapia para o seu futuro desempenho como profissionais e têm interesse em se aprimorar nessa área de conhecimento. A alta freqüência de estudantes que consideraram a fitoterapia mais eficaz do que os medicamentos convencionais e a baixa freqüência daqueles que associaram plantas medicinais à riqueza da biodiversidade brasileira foram resultados preocupantes. Um ponto positivo foi o grande número de citações de plantas medicinais que contam com algum estudo de validação, como sendo as mais conhecidas e utilizadas. Consideramos interessante que as disciplinas dos Cursos de Farmácia e Biologia, envolvidas com o tema, concentrem‑se no estudo de plantas medicinais já conhecidas e utilizadas pelos estudantes, capacitando‑os nos aspectos técnico‑científicos de cada espécie e seus produtos.

Purification, physicochemical characterization and biological properties of a lectin from Erythrina velutina forma aurantiaca seeds.

A lectin was purified from seeds of Erythrina velutina forma aurantiaca by affinity chromatography on cross-linked guar gum. The lectin is a potent agglutinin for human (minimal concentration of protein able to cause visible agglutination of a 2% erythrocyte suspension varying from 1 to 4 micrograms/ml), rabbit (4 micrograms/ml) and chicken erythrocytes (8 micrograms/ml) but presented low activity against cow (250 micrograms/ml) or sheep (333 micrograms/ml) blood cells. Hemagglutination of human O+ erythrocytes was inhibited by D-lactose (0.2 mM) > D-galactose (0.8 mM) > D-raffinose (2.1 mM). At pH 7.5, chromatography on a Superose 12 HR 10/30 column showed that the lectin was primarily a dimer (56.0 kDa) composed of two identical subunits (31.6 kDa each). A small amount of a tetrameric form was also apparently present. The lectin is a glycoprotein (7.3% carbohydrate), has a pI of 4.5, contains high levels of acidic (Asp and Glu, 64.2 and 51.6 residues/mol, respectively) and hydroxy amino acids (Ser and Thr, 42.9 and 38.5 residues/mol, respectively) but relatively low amounts of sulfur amino acids (Cys and Met, 1.0 and 5.0 residues/mol, respectively) and has an N-terminal sequence of Val-Glu-Thr-Ile/Leu-Pro-Phe-Ser. Its hemagglutinating activity was abolished by heating at 70 degrees C for 10 min. The activation energy (delta G') required for denaturation measured by loss of hemagglutination activity was 24.87 kcal/mol. In rats, the purified lectin (100 micrograms) induced neutrophil migration into the peritoneal cavity (3.7 +/- 0.6 x 10(6) neutrophils/ml) or into the air pouch (2.75 +/- 0.25 x 10(6) neutrophils/ml), 8 and 10 times greater than the negative control, respectively.

Histamine release induced by glucose (mannose)-specific lectins isolated from Brazilian beans. Comparison with concanavalin A.

The histamine releasing properties of glucose (mannose)-specific lectins isolated from Brazilian beans was examined. The Canavalia brasiliensis, Dioclea rostrata, and Dioclea virgata lectins induced histamine release in rat peritoneal mast cells similar to concanavalin A. Less potency and efficacy was observed for Canavalia maritima, Dioclea guianensis, and Dioclea violacea while very low activities were seen for the lectins from Dioclea grandiflora, Canavalia bonariensis, and Cratylia floribunda. The histamine releasing effect was quenched by higher doses of D. virgata lectin similar to what was reported for concanavalin A. This effect was abrogated by increasing the concentration of calcium in the incubating medium. As these above proteins have sites that bind calcium, higher doses of the lectins might withdraw the calcium which is essential for the mast cell secretion.

Human lymphocyte stimulation by legume lectins from the Diocleae tribe.

Lectins from eight leguminous seeds from the Diocleae tribe were compared to Concanavalin A (Con A), a well known T cell mitogen, on the stimulation of lymphocyte proliferation and Interferon gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) from normal volunteers. Lectins from Canavalia brasiliensis and Dioclea virgata induced the highest lymphocyte proliferation, both much higher than levels obtained with Con A, whereas lectins from Dioclea guianensis var. lasiophylla and from Canavalia bonariensis induced the lowest stimulation. Lectins from Dioclea rostrata, D. grandiflora, D. violacea and Cratylia floribunda induced intermediate levels of proliferation. The highest stimulation for IFN-gamma production was obtained with the lectin from D. rostrata, followed by those of C. floribunda and C. brasiliensis; only the lectins from D. virgata and C. bonariensis induced an IFN-gamma production lower than the one obtained by Con A-stimulation. Since all these legumes belong to the same tribe of C. ensiformis (Con A), and all are supposed to exhibit very similar lectins, it is interesting the high variation in the stimulation of lymphocyte proliferation. It is also noteworthy the dissociation between this parameter and IFN-gamma production in the case of D. virgata. A detailed analysis on the structure of such lectins, and their ligand sugars on lymphocyte surface is necessary to further explore such differences.

The complete amino acid sequence of the major alpha subunit of the lectin from the seeds of Dioclea grandiflora (Mart).

The complete amino acid sequence of the major alpha subunit of the lectin from seeds of Dioclea grandiflora was determined. The sequence was deduced from analysis of peptides derived from the native alpha subunit by digestion with trypsin, chymotrypsin, the Staphylococcus aureus V8 protease, and pepsin; and from larger peptides produced by digestion of the citraconylated protein with trypsin. The alpha subunit consists of a single polypeptide chain of 237 amino acids which differs from the sequence of concanavalin in 53 positions. Significant levels of heterogeneity were observed in five positions in the sequence.