In vitro antibacterial activity of a 7-O-beta-D-glucopyranosyl-nutanocoumarin from Chaptalia nutans (Asteraceae)

Ethanolic crude extracts from the roots of Chaptalia nutans, traditionally used in Brazilian folk medicine, were screened against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by using the disk diffusion test technique. S. aureus with 14 mm inhibition zone was considered susceptible. E. coli and P. aeruginosa without such a zone were considered resistant. As a result of this finding, the ethanolic crude extract was fractionated on silica gel column chromatography into five fractions. The ethyl acetate fraction was active against S. aureus and Bacillus subtilis. Further column chromatography separation of the ethyl acetate fraction afforded 30 fractions, which were assayed against S. aureus. Fractions 16 and 17 showed inhibition zones with S. aureus, indicating the presence of active compounds, and were subjected to purification by repeated preparative thin layer chromatography. The pure compound 7-O-beta-D-glucopyranosyl-nutanocoumarin inhibited B. subtilis and S. aureus at concentrations of 62.5 g/ml and 125 g/ml, respectively. The antibacterial property of C. nutans appears to have justified its use for the treatment of wounds, which are contaminated through bacterial infections.     

Taxonomy and distribution of Chaptalia dentata and C. Albicans (Asteraceae: Mutisieae)

Chaptalia dentata (L.) Cass. andC. albicans (Sw.) Vent. ex Steudel incorrectly have been recognized as conspecific in recent treatments. Although they are vegetatively similar, they differ in features of the flowers and fruits—especially the mature achenes. Both species occur in the Bahamas and the Greater Antilles of the West Indies:Chaptalia dentata is endemic to that area, absent only from Jamaica;C. albicans is more widespread, as it occurs in Jamaica as well as in scattered localities on the American mainland—southern Florida, various localities in Belize, Honduras, and Guatemala, and the Mexican states of Veracruz, San Luis Potosí, Chiapas, and Yucatán.     

Coumarins from Cedrelopsis grevei (Ptaeroxylaceae)

The stem bark of Cedrelopsis grevei Baill. has yielded the first reported examples of 5-prenylated coumarins, cedrecoumarin A and B as well as the known coumarins, cedrelopsin, scoparone, O-methylcedrelopsin and norbraylin, and the known chromones ptaeroglycol and ptaeroxylinol.     

Flavonoids from Ochna integerrima

Two biflavonoids namely, 2",3"-dihydroochnaflavone and 2",3"-dihydroochnaflavone 7"-O-methyl ether, and a flavonoid glycoside, 6-gamma,gamma-dimethylallyltaxifolin 7-O-beta-D-glucoside were isolated from the leaves of Ochna integerrima.     

A new species of Centaurea (Asteraceae) from Sicily

A new species of Centaurea, Centaurea sicana , endemic to Sicily, is described. This new taxon is close to Centaurea parlatoris and Centaurea giardinae (Sect. Dissectae), the former occurring at Palermo and in the Madonie Mountains, while the latter occurs on the Etna volcano. The new species has so far been found only on the Sicani Mountains, a limestone mountain range in western Sicily, while the related species occur in the surrounding mountains. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 785–788.     

A new species of Pleiotaxis (Asteraceae) from Angola

A new species from Angola, Pleiotaxis angolensis (tribe Mutisieae, Asteraceae), is described. We detail the principal differences from the most similar taxon, Pleiotaxis subscaposa .     

A new species of Kleinia (Asteraceae) from Somalia

The new species Kleinia caespitosa, from crevices in limestone rocks at 1850–1900 m in northern Somalia, is described and illustrated. It is compared to the widespread and sympatric K. grantii, as well as to K. saginata in Oman.     

A new Haplopappus (Asteraceae: Astereae) from Nevada

A new species, Haplopappus graniticus, is described and illustrated. Its relationships seemingly lie with section Tonestus but its narrow heads and imbricated phyllaries are anomalous in that section.     

Flavonoids from Serratula komarovii Iljin (the Asteraceae Family)

Russian Journal of Bioorganic Chemistry - The genus Serratula L. (the Asteraceae family) is represented by two species in the Russia’s Far East: Serratula manshurica Kitag. and Serratula...     

Three new species of Senecio (Asteraceae) from Mexico

Senecio moranii, Senecio martirensis, andSenecio semperamatae, all from Mexico, are described as new.     

A new species of Centaurea (Asteraceae) from Calabria (S Italy)

A new species is described here from the Presila in Calabria (S Italy) and named Centaurea calabra. It belongs to Centaurea sect. Phalolepis and is related to the C. deusta group, namely to C. sarfattiana. Taxonomical characteristics, distribution, and ecology of the new Centaurea are also provided.     

Coumarins from the Malagasy Cedrelopsis rakotozafyi Cheek and Lescot (Rutaceae)

A phytochemical analysis of the bark of the Malagasy Cedrelopsis rakotozafyi Cheek and Lescot (Rutaceae) yielded the novel 8-hydroxy-7-methoxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, and 7-hydroxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, 5,6,7-trimethoxy-2H-1-benzopyran-2-one, scoparone, scopoletin, lupeol and β-amyrin. The placement of Cedrelopsis within the Rutaceae is supported phytochemically by the typically Rutaceous coumarins isolated.     

Biology of afroalpineDendrosenecio (Asteraceae)

The genusDendrosenecio (giant groundsels), encompassing three species and 12 subspecies, is endemic to the high mountains of East and Central Africa where it constitutes the most conspicuous components of the afroalpine vegetation. Two lifeforms, the arborescent and the prostrate rhizomatous, are regarded as the results of evolution from forest-living woody or herbaceous ancestors. Due to the uninterrupted growth period in the tropics, there are no anatomical or morphological features which allow conventional age determination. However, stem elongation rates have been determined (3–5.5 cm per year) and indicate an age of about 250 years for the tallest arborescent Dendrosenecios which may reach a height of 10 m. 30 to 120 large leaves are clustered in an enormous terminal rosette, justifying the term giant rosette plants. A leaf bud, consisting of about as many developing leaves as the rosette contains, is found in the center. During the nocturnal frost period the adult rosette leaves form a so-called night-bud by nyctinastic upwards bending and thus protect the leaf bud from freezing by insulation. The stem is surrounded by a mantle of persistent dead leaves; this ameliorates the microclimate of the pith-cells which greatly contribute to water transport into the leaves. Below the leaf rosette a zone of putrefaction is found, from where the decay of the dead leaves apparently provides nutrients directly to the growing stem. The population dynamics of the arborescentD. keniodendron is characterized by a simultaneous inflorescence development at irregular intervals of up to more than twenty years. Due to sporadic flowering and a seedling survival rate of less than 1%, oscillations of the population size are to be expected.     

The Subfamily Mutisioideae (Asteraceae)

The subfamily Mutisioideae (74 genera, ca. 865 species), which comprises three tribes, Mutisieae (43 genera, ca. 500 species), Nassauvieae (25 genera, ca. 315 species), and Stifftieae (six genera, 48 species), is analyzed at the generic level. A total of 87 genera traditionally related to Mutisioideae were studied. The genera of Mutisioideae are described and illustrated, and keys to tribes and genera are given. Corollas, anthers, styles, and pollen, are analyzed and discussed. The styles (smooth, rugulose to papillose, papillae short and rounded) constitute the main characters for delimiting the subfamily. The presence and distribution of the style papillae support the recognition of three tribes, although other characters as corolla shape contribute to their definition. The pollen of Nassauvieae can be clearly differentiated from the pollen of Mutisieae and Stifftieae. The morphology supports the exclusion of Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, and Warionia but not the exclusion of other taxa, for example, Hecastocleis, the Gochnatia complex, or the Ainsliaea group members.

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Resumen  La subfamilia Mutisioideae (74 géneros, ca. 865 especies), que comprende tres tribus, Mutisieae (43 géneros, ca. 500 especies), Nassauvieae (25 géneros, ca. 315 especies), y Stifftieae (6 géneros, 48 especies), es analizada a nivel genérico. Se estudió un total de 87 géneros que tradicionalmente fueron relacionados a Mutisioideae. Se describen e ilustran los géneros de Mutisioideae, y se proveen claves para las tribus y los géneros. Se analizan y discuten las corolas, anteras y estilos. Los caracteres del estilo (glabro, ruguloso a papiloso, las papilas cortas y redondeadas) son los más importantes para delimitar la subfamilia. La presencia y distribución de las papilas del estilo ayudan al reconocimiento de las tres tribus, aunque otros caracteres como la forma de la corola contribuyen a su definición. El polen de Nassauvieae se puede diferenciar claramente del polen de Mutisieae y Stifftieae. La morfología apoya la exclusión de Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, y Warionia, pero no la exclusión de otros taxa, por ejemplo, Hecastocleis, los miembros del complejo Gochnatia o del grupo Ainsliaea.

     

New species of llerasia (Asteraceae: Astereae) from Peru

Two new species from Peru,Llerasia pascoensis Sagást. & Dillon andLl. sanmartinensis Sagást. & Dillon are described and illustrated, and their relationships discussed. A key to the Peruvian species ofLlerasia is presented. Also, a notable range extension into northern Peru is reported forLl. lindenii Triana, a species previously known only from Colombia and Ecuador.