Dihydroisocoumarin from Xyris pterygoblephara active against dermatophyte fungi

The ethanol extract from Xyris pteygoblephara aerial parts was evaluated against five microorganism strains, by the microdilution and agar diffusion methods. Extract fractionation led to the isolation of three compounds, whose structures were assigned by spectrometric data (113 and 2D NMR, IR, MS and UV) as (3R,4R)-(-)-6-methoxy-3,4-dihydro-3-n-pentil-4-acethoxy-1H-2-benzopyran-1-one (1), moronic acid and quercetin. The absolute configuration of I was defined by circular dichroism spectroscopy and comparison with data reported for other dihydroisocoumarins. Assay of 1 (100 mu g/disc) by the agar diffusion method against clinical isolates of the dermatophytes Epidermophyton floccosum (inhibition zone, mm +/- s.d.: 4.5 +/- 0.8), Trichophyton mentagrophytes (4.8 +/- 0.4) and Trichophyton rubrum (10.2 +/- 0.8) revealed similar inhibition zones to the positive control amphotericin B (32 mu g/disc; 5.0 +/- 0.2; 5.0 +/- 0.6 and 8.8 +/- 1.2, respectively). The result corroborates the ethnomedical use of Xyris species to treat dermatitis. (C) 2007 Elsevier Ltd. All rights reserved.

Caracterização anatômica foliar para 14 espécies de Xyris L. (Xyridaceae) da Serra do Cipó, MG, Brasil

As folhas de X. anamariae, X. archeri, X. hymenachne, X. melanopoda, X. minarum, X. obcordata, X. paraensis, X. pilosa, X. platystachia, X. pterygoblephara, X. savanensis, X. spinulosa, X. tortilis e X. tortula, foram preparadas segundo técnicas usuais para estudos anatômicos. A análise comparativa, da região basal desses órgãos, mostrou diferenças na estrutura da epiderme, na organização do mesofilo e no número e grau de agrupamento dos feixes vasculares, dependendo da espécie considerada. Esses aspectos foram utilizados na caracterização de cada representante estudado e, analisados em conjunto para indicar formas diferentes de especialização foliar, relacionadas à deficiência hídrica.

Intercellular pectic protuberances in leaves of some Xyris species (Xyridaceae)

Mature leaves of eight species of Xyris were prepared by standard methods for electron transmission microscopy. Wartlike intercellular pectic protuberances were observed on the surface of inner periclinal walls of epidermal cells in Xyris obcordata, Xyris hymenachne, and Xyris pterygoblephara. In the latter, the protuberances also occur on the surface of parenchymatic mesophyll cells; they frequently project into intercellular spaces and may connect opposing cells. For the genus Xyris, the intercellular pectic protuberances may be considered taxonomically significant at the species level.

Occurrence of form PIIcf sieve-element plastids in Xyris species (Xyridaceae)

Mature leaf fragments from eight species of Xyris from the Serra do Cipo, State of Minas Gerais, Brazil, were prepared by the usual methods for electron microscopy. Ultrastructural analysis of phloem shows the occurrence of nacreous walls with a polylamellate structure in the sieve-elements of X. tortilis and plastids similar to P-plastids, form PIIcf in the sieve-elements of all investigated species.

Systematic position of Xyris: Flower and seed anatomy

Flower anatomy, embryology, and seed anatomy are described for some Brazilian species of Xyris section Nematopus and reviewed with respect to the systematic position of Xyris and allied taxa in Commelinanae. Apart from tenuinucellate ovules (shared with Poales, Mayaca, and Eriocaulaceae), Xyris lacks some of the synapomorphies of other genera that are sometimes included in Xyridaceae (Aratitiyopea, Achlyphila, Abolboda, and Orectanthe), such as inaperturate spinulate pollen; Xyris has monosulcate reticulate pollen. There is an unusual degree of variation among different genera of Xyridaceae for characters such as tapetum type, indicating that the monophyly of the family requires testing. However, while several characters indicate two generic groups, there is much missing critical information for embryological and seed coat characters in other Xyridaceae.

Systematic vegetative anatomy and ensiform leaf development in Xyris (Xyridaceae)

Ensiform leaf development in monocotyledons follows a broadly similar sequence in a wide range of relatively unrelated taxa, indicating a plastic developmental pattern, possibly associated with stressed environmental conditions, since Xyris species tend to grow in relatively damp but nutrient-poor environments. The bifacial leaf sheath surrounds the apex and the subadjacent primordium. A conical unifacial leaf tip 'Vorlauferspitze' is established at an early stage, followed by extension growth in the region behind it, generating a unifacial ensiform blade. Root and rhizome structure are also described in a systematic context, particularly in comparison with related taxa in Xyridaceae and other commelinoid monocotyledons, although information on these structure is relatively sparse.

Submicroscopical features of leaves of xyris species

The leaf infrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a nehvork ofpectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous peg cells in the mesophyll and drops of phenolic compounds inside the epidermal cells.

Desenvolvimento de óvulo, fruto e semente de Xyris (Xyridaceae, Poales)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Development of ovule, fruit and seed of Xyris (Xyridaceae, Poales) and taxonomic considerations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

On the taxonomic value of the anatomical structure of vegetative organs and inflorescence axis of Abolboda species (Xyridaceae - Poales)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

FLORAL ANATOMY of XYRIDS (POALES): CONTRIBUTIONS TO THEIR REPRODUCTIVE BIOLOGY, TAXONOMY, and PHYLOGENY

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biogeografia de formações vegetais: classificação de um encrave vegetacional : Parque Estadual do Rio Turvo, Barra do Turvo, SP

Pós-graduação em Geografia - IGCE

Ovule, fruit and seed development in Abolboda (Xyridaceae, Poales): implications for taxonomy and phylogeny

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morfoanatomia de folha e escapo de Abolboda (Xyridaceae - Poales)

Os representantes de Xyridaceae estão agrupados em duas subfamílias: Xyridoideae, que compreende o gênero Xyris e Abolbodoideae, que compreende os gêneros Abolboda, Achlyphila, Aratitiyopea e Orectanthe. Como as relações entre as espécies de Xyridaceae e delas com outras Poales não estão bem estabelecidas, o trabalho teve como objetivo a caracterização morfológica e anatômica de folhas e escapos de táxons brasileiros de Abolboda buscando levantar estruturas que os diferenciassem e que servissem de comparação com os demais gêneros. Foram estudadas: Abolboda poarchon var. poarchon, A. poarchon var. intermedia, A. pulchella e A. macrostachya. As características morfológicas como comprimento e largura de folhas, comprimento de escapos e de bainhas dos nós dos escapos e número de feixes vasculares no mesofilo são importantes para diferenciar os táxons entre si. Folhas e escapos com epiderme unisseriada, estômatos localizados pouco acima do nível das demais células epidérmicas, presença de hipoderme, parênquima paliçádico e lacunoso e feixes vasculares colaterais; folhas com estômatos paracíticos somente na face abaxial e margem com colênquima logo abaixo da epiderme, caracterizam anatomicamente os táxons de Abolboda estudados. As espécies de Abolboda apresentam algumas características anatômicas contrastantes com Xyris e outras similares com os demais gêneros, corroborando a divisão da família em duas subfamílias. A presença de nó nos escapos de Abolboda é um caráter diagnóstico do gênero. Abolboda macrostachya apresenta características anatômicas exclusivas da espécie. A. poarchon e A. pulchella apresentam muitas características anatômicas semelhantes e ocorrem simpatricamente.

Anther wall development, microsporogenesis, and microgametogenesis in abolboda and orectanthe: contributions to the embryology of xyridaceae (poales)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)