Sueli Maria Gomes

Anatomia foliar de espécies de Myrtaceae: contribuições à taxonomia e filogenia

Taxonomical and phylogenetical studies have used anatomical information. In order to contribute to these studies, paradermal and cross sections of the median leaf blade portion of Campomanesia adamantium (Camb.) O. Berg, Myrcia cordiifolia DC., M. decrescens O. Berg and M. torta D.C. were examined. The anatomical characters were compared to the other species described in the literature. Some characteristics were irrespective of the four examined species: unistratified epidermis, unicellular trichomes, hypostomatic leaves, paracytic stomata, oil glands on both sides, dorsiventral mesophyll and bicollateral bundles on the midrib. The following characters appear to be taxonomically useful in the family: epidermal common cell format, presence of dibrachiate trichomes, presence of colorless subepidermal cell layers and midrib shape. The morphology and number of overlying cells associated with the glands have taxonomic utility. The 144 exsicates examination showed that the glabrescence is a widespread phenomenon in the Myrtaceae. The trichome fall can be due to its narrow base and to the foot cell absence. The characters were analyzed in the light of recent phylogenetic studies, highlighting the hypothesis related to the presence of epidermal cells with possible transfer cell function. The anatomical features provided data for wider comparative analysis amongst Myrtaceae taxa and ensured the construction of a cladogram, where Leptospermum and Eucalyptus species occupied the basal position, in line with reported phylogenies.

Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.

Morfo-anatomia de frutos secos em espécies de Apocynaceae: significado ecológico e evolutivo

Dry fruits predominate in Apocynaceae species, especially the follicle type reported for Aspidosperma parvifolium A.DC., Mesechites mansoana (A.DC.) Woodson and Prestonia coalita (Vell.) Woodson. Anatomical analysis of intact and open fruits was carried out to compare characteristics with those of other species of this family. We found that the fruit of P. coalita is a bicarpellary septicidal capsule, showing that this genus has two types of fruits instead of one as previously thought. Capsules may be found in other Prestonia species and in other Apocynaceae genera reported as having follicles. For Apocynaceae, some taxonomic characters should be considered such as thickness and number of pericarp layers and sublayers; presence of aerenchyma, sclereids, non-lignified fibres, secretory idioblasts in the mesocarp; vascular-bundle position in the mesocarp; endocarp thickness and fibre orientation; presence of internal ribs in the pericarp. Furthermore, the role of the internal ribs of the pericarp, as well as the non-lignified mesocarp fibres for the xerocastic mechanism are discussed. A total dehydration test was developed to determine maximum pericarp curvature and its implications for the dehiscence process.

Arquitectura foliar de las Lauraceae del Distrito Federal, Brasil, y nuevos patrones de venación propuestos

Fueron estudiadas las hojas de 18 especies de Lauraceae que crecen en el Distrito Federal (Brasil), con el objetivo de caracterizar sus patrones de venacion e identificar caracteristicas utiles en su diferenciacion taxonomica, para que junto a su morfologia se puedan obtener criterios utiles que ayuden en su identificacion vegetativa. Las hojas fueron diafanizadas, coloreadas y fotografiadas. Los patrones de venacion del segundo, tercero, cuarto y quinto orden fueron descritos e ilustrados para las especies estudiadas, que presentaron una venacion secundaria de tipo broquidodroma o eucamptodromo-broquidodroma, excepto en Crytocarya aschersoniana y Ocotea aciphylla con venacion broquidodroma prominula reticulada. La densidad de areolas se mostro como un buen caracter taxonomico, lo que no ocurrio con el numero de lados que estas poseen. Fueron propuestos los conceptos de nudos y ramas de las venulas y criterios para la clasificacion de sus ramificaciones. La mayoria de las especies poseen venulas ramificadas. Los caracteres analizados, unidos con los morfologicos tales como tipo de indumento, formas de borde, y presencia y/o ausencia de domacios, posibilitaron la diferenciacion de las 18 especies estudiadas, evidenciando la clara importancia de la arquitectura foliar en el reconocimiento taxonomico de especimenes en estado vegetativo.

Potential radical-scavenging activity of Pouteria caimito leaves extracts -

1 Faculdade de Ciências da Saúde, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, Brazil. 2 Instituto de Química. Universidade de Brasilia, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, Brazil. 3 Departamento de Botânica, Instituto de Ciências Biológicas, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, Brazil. 4 Departamento de Ensino de Graduação, Instituto Federal de Educação, Ciência e Tecnologia Goiano, Campus Rio Verde, Rod. Sul Goiana, Km 01, Setor Universitário Rio Verde, GO, Brazil.

Paspalum minutispiculatum (Poaceae, Panicoideae): A New Annual Species from Central Brazil

Abstract Paspalum (Poaceae, Panicoideae) is a large genus comprising approximately 330 species, of which 210 are cited for Brazil. Paspalum minutispiculatum is similar to other related species of the informal “Humboldtiana” group, but this new species is annual and lacks rhizomes. This work establishes the distinction between this new species and related ones from this group, and contributes to a better characterization of the little known P. bicilium. Micromorphological characters of the upper anthecium and anatomical characters of the root, culm, and leaf of both species were analyzed. The new species appears to be endemic to the Federal District. It grows along trails in gallery forest, which is a rare habitat for this genus. The present work includes a key for species of the “Humboldtiana” group.