Tamizaje de alcaloides y saponinas de plantas que crecen en Cuba: I: Moa 1 / Screening of alkaloids and saponins in Cuban plants: I: Moa I

Se estudiaron 99 muestras de 98 especie pertenecientes a 40 familias de la flora cubana, a las que se les realizó pruebas químicas de detección de alcaloides y saponinas. El número de pruebas positivas fue del 46,8 y 72,4 por ciento , respectivamente

Los pólenes de gramíneas y su relación con manifestaciones alérgicas en Costa Rica / Pollen of gramineae and its relation with allergic effects in Costa Rica

La alergia al polen es un problema sanitario importante en Costa Rica. Este volumen presenta una revisión junto con nuevos datos sobre el tema, para el cual no parece haber estudios igualmente detallados en otros países latinoamericanos, Junto a la descripción de los métodos de muestreo se presenta además una introducción a los otros trabajos agrupados en este suplemento. Se comparó cien sujetos sanos, no alérgicos, con 480 pacientes de rinitis, conjuntivitis, asma bronquial y/o dermatitis atópica. El polen de la familia Poaceae es el principal en cuanto a sensibilización alérgica Tipo I, porque (1) porduce gran cantidad de polen, (2) se encuentra en variedad de climas y hábitats y (3) sus proteínas son particularmente alergénicas. En 1986, un 0.33 por ciento de la población del país se convirtió en nuevos pacientes de alergia, y la tendencia es al aumento. Los métodos normales resultaron satisfactorios al ser aplicados a polen congelado con una vida activa media de tres años. Las pruebas epicutáneas se realizaron por dos años consecutivos usando únicamente mezclas de extractos la primera etapa y luego extractos de cada especie para una segunda etapa. Todos 1/10 p/v, glicerinados.

Avaliacao de metodologias para a determinacao de pro-vitaminas A / Evaluation of methodologies for the determination of provitamins A

Varios metodos analiticos foram desenvolvidos com a finalidade de obter procedimentos simples, rapidos e economicos para a determinacao de pro-vitamina A em alimentos. Neste trabalho tres desses metodos foram avaliados: os de COST91,IVACG e RODRIGUEZ-AMAYA et alii simplificado. Os alimentos escolhidos foram couve, cenoura, mamao e tomate, devido as suas caracteristicas distintas quanto a composicao de pro-vitamina A. As principais deficiencias apresentadas pelo metodo recomendado por COST91 foram a extracao incompleta e a saponificacao drastica. Outra grande falha do metodo foi a nao separacao entre alfa e beta-caroteno, e a nao consideracao da alfa e beta-criptoxantina e do beta-caroteno. Para o metodo apresentado pelo IVACG, a extracao foi insuficiente apenas para couve. Esse metodo demonstrou ser mais versatil que COST92, pois permitiu a separacao das diferentes pro-vitaminas. Dos procedimentos de saponificacao sugeridos, a saponificacao a frio confirmou ser a tecnica mais aconselhavel. O metodo de RODRIGUEZ-AMAYA et alii simplificado mostrou ser o mais indicado, principalmente pela sua simplicidade e exatidao

Contenido de niquel en algunos vegetales cultivados en una zona niquelifera / Nickel content in certain vegetables cultured in a nickel producing zone

Se determinó el contenido de níquel por espectrofotometría atómica en 8 vegetales procedentes de Mayarí, zona niquelífera de la provincia de Holguín, y en 3 vegetales de Quivicán, provincia La Habana. Los contenidos de níquel en los vegetales de Mayarí fueron significativamente mayores (p<005) que en los de Quivicán. En los productores de Mayarí las concentraciones medias oscilaron entre 0,404 mg/kg para el pepino y 0,964 mg/kg para la col. Seis de los 8 vegetales de Mayarí tuvieron concentraciones medias de níquel por encima del límite máximo de residuos establecidos por el Consejo de Ayda Mutua Económica

Carotenoids and provitamin A value of some Brazilian sweet potato cultivars (Ipomoea batatas Lam.) / Carotenoides e valor pro-vitaminico A de alguns cultivares de batata-doce (Ipomoea batatas Lam.)

In order to determine the carotenoid content and provitamin A value of raw and cooked sweet potatoes, ten cultivars from "Instituto Agronomico de Campinas" and "Centro Nacional de Pesquisa de Hortalicas da Empresa Brasileira de Pesquisa Agropecuaria - EMBRAPA" were analysed. The techniques used included open column chromatography and spectrophotometry. Seven carotenoids were identified: Beta-carotene-5,6,5'6'-diepoxide; Beta-carotene-5,6-epoxide; luteochrome; alfa-zeacarotene; Beta-zeacarotene and aurochrome. Beta-carotene was the main carotenoid of the following cultivars: Centennial, Heart Gold, Anapolis, Acadian, Morada Inta, Vineland Bush and clone CNPH. Luteochrome was the principal carotenoid of Monalisa, IAC-2-71 and SRT-252 cultivars. For raw roots the vitamin A value varied from 1 retinol equivalents/100g for IAC-2-71 cultivar to 3,703 retinol equivalents/100g for Acadian. For cooked roots, Acadian cultivar presented the highest provitamin A activity, with 4,021 retinol equivalents/100g. The loss of Beta-carotene due to cooking varied from 4.5% to 17.8% in accordance with the kind of cultivar

Estudo da ocorrência de enteroparasitas em hortaliças comercializadas na regiäo metropolitana de Säo Paulo - SP, Brasil: II. Pesquisa de protozoários intestinais / Study of the occurrence of intestinal parasites os vegetables comercially traded in the metropolitan area of S. Paulo, SP - Brazil: II. Research into protozoan cysts

Foram analisadas hortaliças "in natura", comercializadas na Regiäo Metropolitana de Säo Paulo, SP-Brasil, visando à pesquisa e à identificaçäo de cistos de protozoários de interesse médico. As hortaliças constituídas de 50 amostras de cada variedade, consistiram em: alface (Lactuca sativa), variedades lisa e crespa, escarola (Chichorium sp) e agriäo (Nasturtium officinale). Os resultados evidenciaram elevados percentuais de contaminaçäo, em todas as variedades de hortaliças analisadas porém as freqüências de protozoários foram maiores no agriäo. As amostras de alfaces apresentaram os menores percentuais de contaminaçäo, enquanto que a escarola apresentou valores geralmente situados entre o agriäo e as alfaces. Observou-se uma grande variedade de protozoários, cujas freqüências de ocorrência na populaçäo residente na Regiäo Metropolitana de Säo Paulo säo igualmente elevadas. Os mais freqüêntes foram Entamoeba sp (com 4 e 8 núcleos) e Giardia sp. Foram também isolados cistos de Iodamoeba sp, Endolimax sp e Chilomastix sp. Os elevados níveis de contaminaçäo fecal encontrados nas amostras analisadas apontam para a importância dos alimentos na transmissäo de protozoários intestinais

Evaluation of the molluscicidal properties of Euphorbia splendens var. hislopii (n. e. b.) (Euphorbiaceae) - 1: experimental test in a lentic habitat

The latex of Euphorbia splendens var. hislopii, at concentrations between 5 to 12 mg/l, kills 100% of the population of Biomphalaria glabrata in a lentic habitat, after 24 h. The lyophilized latex, stocked for 18 months, killed only 34.2% of the snails, at the concentration of 5 mg/l, and 96.0% at 12 mg/l. No lethal effect was observed among Pomacea haustrum exposed to the same concentrations of the molluscicide

Chloroplast biogenesis. Detection of monovinyl protochlorophyll(ide) b in plants.

The occurrence of protochlorophyllide b and protochlorophyllide b phytyl ester in green plants is described. The chemical structure of protochlorophyllide b phytyl ester was established by proton nuclear magnetic resonance, fast atom bombardment mass spectroscopic analysis, and chemical derivatization coupled to electronic spectroscopic analysis. The macrocycles of protochlorophyll(ide) b are identical to those of conventional protochlorophyll(ide) except for the presence of a formyl group instead of a methyl group at position 3 of the macrocycles. They differ from chlorophyll(ide) b by the presence of an oxidized double bond at positions 7 and 8 of the macrocycles. The trivial name protochlorophyll(ide) b is proposed to differentiate these two tetrapyrroles from conventional protochlorophyll(ide), which in turn will be referred to as protochlorophyll(ide) a. Protochlorophyll(ide) b appears to be widely distributed in green plants. Its molar extinction coefficients in 80% acetone and diethyl ether are reported. The impact of this discovery on the heterogeneity of the chlorophyll a and b biosynthetic pathways is discussed.

Purification and amino acid sequence of a bitter gourd inhibitor against an acidic amino acid-specific endopeptidase of Streptomyces griseus.

An inhibitor (BGIA) against an acidic amino acid-specific endopeptidase of Streptomyces griseus (Glu S. griseus protease) was isolated from seeds of the bitter gourd Momordica charantia L., and its amino acid sequence was determined. The molecular weight of BGIA based on the amino acid sequence was calculated to be 7419. BGIA competitively inhibited Glu S. griseus protease with an inhibition constant (Ki) of 70 nM, and gel filtration analyses suggested that BGIA forms a 1:1 complex with this protease. However, two other acidic amino acid-specific endopeptidases, protease V8 from Staphylococcus aureus and Bacillus subtilis proteinase (Glu B. subtilis protease), were not inhibited by BGIA. BGIA had no inhibitory activity against chymotrypsin, trypsin, porcine pancreatic elastase, and papain, although subtilisin Carlsberg was strongly inhibited. The amino acid sequence of BGIA shows similarity to potato chymotrypsin inhibitor, barley subtilisin-chymotrypsin inhibitor CI-1 and CI-2, and leech eglin C, especially around the reactive site. Although the residue at the putative reactive site of these inhibitors is leucine or methionine, the corresponding amino acid in BGIA is alanine.

Comparison of the antimicrobial and cytotoxic activities of twenty unsaturated sesquiterpene dialdehydes from plants and mushrooms.

Twenty unsaturated sesquiterpene dialdehydes were tested for antimicrobial, algaecidal, cytotoxic, and mutagenic activity. In addition to the known antifungal activity, polygodial (1) also exhibited antibacterial and cytotoxic activity; epipolygodial (2) was slightly less active. The most active compounds were: isovelleral (7), isoisovelleral (8), velleral (20), and methylmarasmate (6). With the exception of velleral (20), they also exhibited mutagenic activity in the Salmonella/microsome assay. Derivatization to less polar compounds usually increased the antimicrobial and cytotoxic effects and reduced mutagenicity, while the introduction of hydroxyl groups had the reverse effect.

Chemical, physiological, and toxicological aspects of the essential oil of some species of the genus Bystropogon.

The composition of the essential oils of Bystropogon plumosus, B. origanifolius var. palmensis, B. wildpretii, B. maderensis, and B. canariensis var. smithianus were studied by GLC and GLC/MS. The first four species provide relatively similar oils characterized by monoterpene ketones as the main constituents while the last species is quite different with main constituents consisting of mono- and sesquiterpene hydrocarbons. In B. plumosus the ontogenetic variation of the monoterpene ketones was studied for a period of four years. During this time the behaviour of pulegone was inversely correlated with that of menthone and isomenthone. Pulegone was the most active compound of the monoterpene ketones in antimicrobial tests using three species of bacteria and fungi, respectively.

Atrial natriuretic peptide hormonal system in plants.

To determine if atrial natriuretic peptides are present in plants as well as animals, where they are important for water and sodium metabolism, the leaves and stems of the Florida Beauty (Dracena godseffiana) were examined. The N-terminus consisting of amino acids (a.a.) 1-98 (i.e., pro ANF 1-98), the mid portion of the N-terminus (a.a. 31-67; pro ANF 31-67), and C-terminus (a.a. 99-126; ANF) of the 126 a.a. atrial natriuretic factor (ANF) prohormone were all present in the leaves and stems of this plant. The concentrations of pro ANF 1-98, pro ANF 31-67 and ANF-like peptides of 120 +/- 20, 123 +/- 21, and 129 +/- 20 ng/g of plant tissue in leaves and 109 +/- 20, 96 +/- 21, and 124 +/- 18 ng/g of tissue, respectively, in the stems were lower (P less than 0.05) than their concentrations in rat (Rattus norvegicus) heart atria of 196 +/- 40, 192 +/- 28, and 189 +/- 15 ng/g of tissue respectively, but higher (P less than 0.001) than their respective concentrations of 4.3 +/- 1.4, 4.1 +/- 1.2, and 3.9 +/- 1 ng/g of rat heart ventricular tissue. We conclude that the atrial natriuretic peptide-like hormonal system is present in the plant kingdom as well as in the animal kingdom.

Extreme variations in the ratios of non-synonymous to synonymous nucleotide substitution rates in signal peptide evolution.

Nucleotide sequences encoding signal peptides from the precursors of alpha-amylase/trypsin inhibitors from cereals are homologous to those corresponding to the precursors of thaumatin II and of plastocyanins. Non-synonymous (KA) and synonymous (KS) rates of nucleotide substitutions have been calculated for all possible binary combinations. Extreme variation in KA/KS ratios has been observed; from the 0.167 average found within the plastocyanin family to an average of 1.90 calculated for the inhibitors/thaumatin II transition. A similar calculation has been carried out for the signal peptide sequences of thionins, which are unrelated to those of the alpha-amylase/trypsin inhibitor family, and an average KA/KS of 0.12 has been obtained. This variation can be largely explained in terms of an empirical index of stability related to amino acid composition and seems to be independent of functional constraints.

R-phycoerythrin as a fluorescent label for immunolocalization of bound atrazine residues.

We established a highly sensitive immunofluorescence procedure for localizing bound atrazine in the aquatic macrophytes Elodea canadensis and E. densa. The technique included biotin-labeled anti-rabbit IgG as a first enhancement step and R-phycoerythrin (R-PE) coupled to streptavidin for fluorescent labeling as a second improvement on the procedure. A comparison with the conventional indirect immunofluorescence method confirmed the superior results of the R-PE approach. The use of atrazine-free plants (grown in charcoal-filtered water) and a variety of other controls excluded both contaminating atrazine and nonspecific incubation constituents as sources of tissue staining. Pre-incubations to block nonspecific binding sites proved to be unnecessary in this system. The highly sensitive procedure described here might be a useful tool for the localization of tissue-bound pesticides in general and possibly of other haptens as well.

Characterization of glucosylceramide from plasma membranes of plant root cells.

Plasma membranes of oat root cells were isolated from intracellular membranes by subfractionation of the microsomal fraction using an aqueous polymer two-phase system. The plasma membranes originated from oat plants which were acclimated to dehydration by exposure to a repeated water-deficit stress program. Glucosylceramides was a major component of the plasma membrane lipids and amounted to 9% of the lipid of control plants and 5% of the lipid of acclimated plants. Structural analysis using FAB-MS showed only one type of glucosylceramides. The constituent monosaccharide was exclusively glucose and the sphingosine base was 4,8-sphingadienine. The fatty acid composition was determined to 24:1-OH, with only trace levels of non-hydroxy acids. The decrease in the level of glucosylceramides during acclimation to dehydration was accompanied by a corresponding decrease in phospholipids and increase in free sterols.

Bioactive neolignans from Endlicheria dysodantha.

From bioactivity-directed fractionation of the EtOH extract of Endlicheria dysodantha, dysodanthin A and dysodanthin B, which are new hexahydrobenzofuranoid neolignans, have been isolated. In addition, the known neolignans, compound 4, which is a burchellin analogue, and megaphone acetate [1] were isolated. All four neolignans showed activities in the brine shrimp lethality test; compounds 1-3 also inhibited the growth of crown gall tumors on potato discs and were cytotoxic to human tumor cells in culture. This is the first report of these neolignans isolated from the genus Endlicheria and of their completely assigned 1H-and 13C-nmr data.

Determination of saccharides in biological materials by high-performance anion-exchange chromatography with pulsed amperometric detection.

High-performance anion-exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD) under alkaline conditions (pH 9-13) separates aminosaccharides, neutral saccharides and glycuronic acids based upon their molecular size, saccharide composition and glycosidic linkages. Carbohydrates were extracted by utilizing 0.5 M H2SO4 (neutral monosaccharides), 0.25 M H2SO4 coupled with enzyme catalysis (glycuronic acids) and 3 M H2SO4 (aminosaccharides). Solid-phase extraction with strong cation and strong anion resins was used to partition the cationic aminosaccharides and anionic glycuronic acids and to deionize acid extracts for neutral saccharides. Separation was conducted on a medium-capacity anion-exchange column (36 mequiv.) utilizing sodium hydroxide (5-200 mM and sodium acetate (0-250 mM) as the mobile phase. The saccharides were detected by oxidation at a gold working electrode with triple-pulsed amperometry. HPAEC-PAD was found superior to high-performance liquid chromatography with refractive index (RI) detection for neutral monosaccharides and aminosaccharides and to low-wavelength UV detection for glycuronic acids in terms of resolution and sensitivity. HPAEC-PAD was not subject to interferences as was the case for low UV detection (210 nm) or RI analyses and was highly selective for mono- and aminosaccharides and glycuronic acids. The use of HPAEC-PAD was applied for the determination of the saccharide composition of organic materials (plant residues, animal wastes and sewage sludge), microbial polymers and soil.

Inhibitory property characterization and reactive site exploration of the arrowhead proteinase inhibitor.

Affinity chromatography was used to separate two components A and B of the crystalline arrowhead proteinase inhibitor. Both A and B are double-headed and multifunctional proteinase inhibitors. Inhibitor A is capable of inhibiting equimolarly trypsin and chymotrypsin simultaneously, and has a weak inhibitory activity toward kallikrein; whereas inhibitor B can inhibit two molecules of trypsin simultaneously, and shows rather higher inhibitory activity toward kallikrein than inhibitor A, but its inhibitory activity toward chymotrypsin is much weaker than that of inhibitor A. The results of chemical modification and the competitive binding of trypsin and chymotrypsin with inhibitor A showed that the two reactive sites of both inhibitors A and B are Lys and Arg residues. Among them the Lys reactive site is specific for inhibiting mainly trypsin, whereas the active domain composed of the Arg reactive site appears to be multifunctional and capable of inhibiting many different Ser proteinases. Based on the structural characteristics of inhibitors A and B, it was predicated that the two reactive sites should be located in the positions Lys-Ser (44-45) and Arg-Tyr-Lys (76-78), respectively. In inhibitor A, there exists another hydrophobic residue involved in inhibiting chymotrypsin. This residue might be situated in the reactive region composed of the Arg reactive site.

Inhibition of HIV-reverse transcriptase activity by some phloroglucinol derivatives.

Four phloroglucinol derivatives, named mallotophenone (5-methylene-bis-2,6-dihydroxy-3-methyl-4-methoxyacetophenone), mallotochromene (8-acetyl-5,7-dihydroxy-6-(3-acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-2,2-dimethylchromene), mallotojaponin (3-(3,3(dimethylallyl)5-(3(acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-phloracetophenone) and mallotolerin (3-(3-methyl-2-hydroxybut-3-enyl)-5(3-acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-phloracetophenone), have been tested for their ability to inhibit the activity of human immunodeficiency virus (HIV)-reverse transcriptase. Under the reaction conditions with (rA)n.(dT)12-18 as the template.primer, the enzyme activity was inhibited by approximately 70% in the presence of 10 micrograms/ml mallotochromene or mallotojaponin, whereas mallotophenone and mallotolerin were much less inhibitory to the enzyme. The enzyme activity was also inhibited, though to lesser extent, by these compounds under similar conditions with initiated MS-2 phage RNA as the template.primer. The mode of inhibition was, as analyzed with mallotojaponin, competivite with respect to the template.primer, (rA)n.(dT)12-18, and non-competitive with respect to the triphosphate substrate, dTTP. The Ki value of mallotojaponin for HIV-reverse transcriptase was determined to be 6.1 microM.