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Bryobrittonia pellucida was described by Williams in 1901 from a sterile specimen. He suggested a relationship with some members of the Pottiaceae. In 1953, Steere described the sporophyte ofB. pellucida and placed it in the Encalyptaceae. The type ofEncalypta longipes Mitten (1865), a fruiting specimen collected by Drummond in western Canada, is what is presently known asB. pellucida; therefore, the new combination,B. longipes, is made. The distinctive morphological and ecological features of the genusBryobrittonia are described in relation to those of the genusEncalypta. On the basis of both sporophytic and gametophytic characteristics,E. streptocarpa andE. procera are the species most closely related toB. longipes.  相似文献   

3.
Simaba guianensis subsp.huberi (Simaroubaceae), restricted to the savannas of the Venezuelan State of Amazonas, is described and illustrated. The new subspecies is distinguished from the other two subspecies ofS. guianensis by its smaller size, characteristics of the leaflets (size, texture, apex shape, and margin curvature), and fruit color.  相似文献   

4.
Simaba ferruginea (Simaroubaceae) is a Brazilian medicinal plant used in traditional medicine to treat several ailments, including gastric ulcers, fever, diarrhea, and dolorous and inflammatory processes. This study examines the chemical composition and antiulcerogenic effects of rhizomes from this plant. Bioassay-guided fractionation led to the isolation of two bioactive indole alkaloids called canthin-6-one (1) and 4-methoxycanthin-6-one (2). The alkaloid fraction and both alkaloids demonstrated potent antiulcerogenic effects when evaluated in gastric lesion-induced animals, as well as significant antinociceptive activity in mice. These results confirm and justify the popular use of S. ferruginea against gastric ulcers and dolorous processes.  相似文献   

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Quassia amara L. (Simaroubaceae) is a species widely used as tonic and is claimed to be an efficient antimalarial all over the Northern part of the Amazon basin. Quassinoid compound Simalikalactone D (SkD) has been shown to be one of the molecules responsible for the antiplasmodial activity of a watery preparation made out of juvenile fresh leaves of this plant. Because of its strong antimalarial activity, we decided to have a further insight of SkD pharmacological properties, alone or in association with classical antimalarials. At concentrations of up to 200μM, we showed herein that SkD did not exert any apoptotic or necrotic activities in vitro on lymphoblastic cells. However, an antiproliferative effect was evident at concentrations higher than 45nM. SkD was inefficient at inhibiting heme biomineralization and the new permeability pathways induced by the parasite in the host erythrocyte membrane. With respect to Plasmodium falciparum erythrocytic stages, SkD was almost inactive on earlier and later parasite stages, but potently active at the 30th h of parasite cycle when DNA replicates in mature trophozoites. In vitro combination studies with conventional antimalarial drugs showed that SkD synergizes with atovaquone (ATO). The activity of ATO on the Plasmodium mitochondrial membrane potential was enhanced by SkD, which on its own had a poor effect on this cellular parameter.  相似文献   

7.
A new quassinoid Picrasin K 1 was isolated from a decoction made of Quassia amara leaves, traditionally used in French Guyana to treat malaria. The structure and relative stereochemistry of 1 was determined through extensive NMR analysis. Picrasin K showed a low activity against Plasmodium falciparum in vitro (IC50 = 8 μM), and a similar low activity on human cancerous cells line (IC50 = 7 μM on MCF-7 cells line).  相似文献   

8.
Ali MS  Saleem M  Ali Z  Ahmad VU 《Phytochemistry》2000,55(8):933-936
The hexane soluble part of Zataria multiflora afforded three new aromatic constituents which include two p-cymene derivatives: multiflotriol (1), multiflorol (2) and an aromatic ester of p-hydroxy benzoic acid (3). In addition to these three new compounds, three known compounds, dihydroxyaromadendrane, luteolin and alpha-tocopherolquinone, have also been isolated for the first time from the same source. The structures of all the isolated constituents were elucidated by means of spectroscopic methods including 2D-NMR techniques.  相似文献   

9.
Michael J. Wynne 《Brittonia》2013,65(1):113-117
The red alga Chrysymenia divaricata Durant, described from New York Harbor, is shown to belong to Lomentaria. The binomial Lomentaria divaricata (Durant) M.J. Wynne comb. nov. is proposed. This name includes the taxonomic synonyms L. baileyana (Harvey) Farlow and Chondrothamnion divaricatum Bailey ex Kützing.  相似文献   

10.
Wm. Wayt Thomas 《Brittonia》1988,40(1):89-105
A complete checklist with synonymy and notes is provided for the Mexican and Central American species ofPicramnia. A key to all taxa of the region is included. Four new taxa (Picramnia guerrerensis, P. hirsuta, P. deflexa, andP. antidesma subsp.nicaraguensis) are described and illustrated, and a new combination (Picramnia antidesma subsp.fessonia) is made.  相似文献   

11.
Wm. Wayt Thomas 《Brittonia》1990,42(3):171-174
A new and rare species,Picramnia bullata, is described, illustrated, and compared to its closest relatives It is unique in its hirsute pubescence, numerous, elongate, bullate leaflets, and long, pendent, unbranched inflorescences.  相似文献   

12.
The new generic name Stirtonanthus is proposed to replace the illegitimate Stirtonia Van Wyk & Schutte (1994), which proves to be a later homonym of Stirtonia A. L . Smith (1926) and Stirtonia R. Brown (1900).  相似文献   

13.
Phylogenetic analyses of rbcL sequence data of representatives of all subfamilies indicate that Simaroubaceae sensu lato is polyphyletic. It represents at least five separate lineages, only three of which (Simarouboideae, Harrisonia, and Kirkioideae) cluster within a robust sapindalean clade. The family is monophyletic only when comprised of members of the subfamily Simarouboideae plus Leitneriaceae, but excluding Harrisonia. Harrisonia is most closely related to Cneorum and Rutaceae. Kirkioideae is distant from Simaroubaceae sensu stricto, although its affinities remain within Sapindales. The other two lineages show an affinity to taxa at some distance from Sapindales: lrvingia with a group of poorly sampled rosid I taxa comprising in part members of Linales and Malphigiales; Picramnia and Alvaradoa cluster together in an isolated position between the broadly comprised groups of rosid I and rosid II. Support for the affinities suggested here is also evident in nonmolecular data sources: wood anatomy, pericarp structure, pollen, and phytochemistry. The elevation of the picramnioid clade, comprising Picramnia and Alvaradoa, to family rank is signaled, and the recognition of Kirkiaceae and Irvingiaceae is substantiated.  相似文献   

14.
Aqueous extracts of Ailanthus altissima bark and foliage were previously shown to be toxic to other plants. Using bioassay-directed fractionation, I isolated the phytotoxic compound from A. altissima root bark and identified it to be ailanthone, a quassinoid compound having molecular mass of 376. Ailanthone was highly phytotoxic, with concentrations of 0.7 ml/L causing 50% inhibition of radicle elongation in a standardized bioassay with garden cress (Lepidium sativum) seeds. Ailanthone exhibited potent pre- and postemergence herbicidal activity in greenhouse trials. Postcmergence activity was especially striking; even the lowest application rate (0.5 kg/ha) caused complete mortality of five of the seven plant species tested within 5 d of treatment. In contrast, the highest application rate (8 kg/ha) did not cause any detectable injury to A. altissima seedlings, indicating the presence of a protective mechanism in the producer species to prevent autotoxicity. Ailanthone was rapidly detoxified in field soil as a result of microbial activity. Applications of ailanthone equivalent to 0.5 and 4.0 kg/ha completely lost their phytotoxicity within ≤5 d when incubated in the presence of nonsterile soil. When incubated with sterile soil under identical conditions, however, ailanthone remained highly phytotoxic throughout the 21-d duration of the investigation. The high level of postemergence herbicidal activity in conjunction with its rapid biodegradation in soil suggest ailanthone may have potential for development as a natural-product herbicide.  相似文献   

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Abstract

A replacement name, Hintoniella is proposed for the generic name Helonastes Hinton, 1968 in the family Elmidae (Coleoptera: Byrrhoidea).  相似文献   

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Casabitoa perfae Alain (Euphorbiaceae) was rediscovered in Alto de Casabito, Cordillera Central, Dominican Republic and was found to be identical withPicramnia dictyoneura (Urban) Urban (Simaroubaceae).  相似文献   

19.
Tom Wendt  Emily J. Lott 《Brittonia》1985,37(2):219-225
Recchia simplicifolia, a new species from southern Veracruz, southern Tabasco and northern Chiapas, represents the first non-microphyllous simple-leaved New World species of Simaroubaceae. It differs from the other two species of Recchia in its simple leaves, cauliflory, and rain forest habitat. Its discovery may necessitate a reevaluation of the relationships of Surianaceae and Simaroubaceae. Although its distribution corresponds to a high-precipitation area which demonstrates strong affinities to the wet Central American flora and may have served as a refuge area for rain forest species during parts of the Pleistocene, its relationships are strictly with Mexican species of the dry Pacific slope, supporting the hypothesis of exchange between the wet and dry Mexican floras during the climatic cycles of the Pleistocene.  相似文献   

20.
Pertya multiflora Cai F. Zhang & T. G. Gao (Asteraceae, Pertyeae) sp. nov. from Zhejiang Province of China is described and illustrated. It is similar to P. pubescens and P. pungens which all have leaves with small spherical glassy tawny glands, but differ by narrowly ovate to nearly elliptic leaves, capitula solitary or in pairs on terminal branches, capitula with 20–30 florets and 9–12‐seriate involucres. Information on phenology, distribution and ecology of P. multiflora is presented, along with a conservation assessment as Critically Endangered (CR) using the IUCN red list criteria. A key to the known species of Pertya in southeast China is provided.  相似文献   

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