Efeito do Potato virus X no conteúdo de fenóis totais e alcalóides em folhas de Datura stramonium

The present paper reports results of the effect of Potato virus X (PVX) on the contents of total phenols and alkaloids in leaves of Datura stramonium. A significant decrease in the contents of phenols and alkaloids was observed in leaves inoculated with PVX (X-I). However, there was an increase in the percentage of phenols in leaves rubbed with phosphate buffer (C1-I) and in leaves from the nodes immediately above, possibly induced by mechanical injury. Gas chromatography/mass spectroscopy revealed amounts of scopolamine in samples submitted to all treatments, except X-I, in which the amount of this alkaloid was low. High amounts of an unidentified compound (molecular ion m/z 302 and a prominent peak at m/z 129) were noted in extracts from leaves X-I, C1-I and leaves from the nodes immediately above the leaves inoculated with PVX. It is suggested that the synthesis and accumulation of the unidentified compound is a result of stress from mechanical injury and virus inoculation.O presente trabalho relata resultados sobre a ação do Potato virus X (PVX) no conteúdo de fenóis totais e alcalóides em folhas de Datura stramonium. Uma diminuição significativa no conteúdo dessas substâncias foi observada nas folhas inoculadas com o PVX (X-I). Entretanto, houve um aumento na porcentagem de fenóis nas folhas friccionadas com tampão fosfato (C1-I) e nas acima das friccionadas, possivelmente induzido por injúria mecânica. Cromatografia gasosa/espectroscopia de massas revelou quantidades de escopolamina nas amostras submetidas a todos os tratamentos, exceto em X-I, no qual a quantidade deste alcalóide foi baixa. Altas quantidades de uma substância não identificada (íon molecular m/z 302 e um proeminente pico a m/z 129) foram notadas em extratos a partir de folhas dos tratamentos X-I, C1-I e nas acima das inoculadas com o PVX. Sugere-se que a síntese e acúmulo da substância não identificada é um resultado do estresse causado pela injúria mecânica e pelo vírus

Does Propolis Contain Tannins?

Although polyphenols have been reported as common constituents of propolis, tannins have \ud rarely been mentioned as its constituents. Propolis samples from seven localities in Brazil \ud were analyzed for detection of proanthocyanidins (condensed tannins) and determination of \ud the tannin content. Positive reaction for proanthocyanidins was observed for all samples \ud tested. The contents of tannins varied in the range 0.6% - 4.1%. A high degree of correlation \ud was noted between total phenols and tannin content. Red and green propolis contained high \ud contents of tannins, while in brown propolis the content was lower. It is suggested that the \ud contents of tannins should be a parameter to be considered in propolis characterization

How diverse is the chemistry and plant origin of Brazilian propolis?

International audiencePropolis is a honey bee product containing chiefly beeswax and resins originated from plant buds or exudates. Propolis resin exerts a diversity of biological activities, such as antitumoral, anti-inflammatory, antimicrobial, and defense of the hive against pathogens. Chemical standardization and identification of botanical sources is crucial for characterization of propolis. Types of Brazilian propolis are characteristic of geographical regions and respective biomes, such as savannas (Cerrado), mangroves, dry forest (Caatinga), rain forests (Amazon, Atlantic, and Interior forests), altitudinal fields (“Campos Rupestres”), Pantanal, and Araucaria forests. Despite the wide diversity of Brazilian biomes and flora, relatively few types of Brazilian propolis and corresponding resin plant sources have been reported. Factors accounting for the restricted number of known types of Brazilian propolis and plant sources are tentatively pointed out. Among them, the paper discusses constraints that honey bees must overcome to collect plant exudates, including the characteristics of the lapping-chewing mouthpart of honey bee, which limit their possibilities to cut and chew plant tissues, as well as chemical requirements that plant resins must fulfil, involving antimicrobial activity of its constituents and innocuity to the insects. Although much still needs to be done toward a more comprehensive picture of Brazilian propolis types and corresponding plant origins, the prospects indicate that the actual diversity of plant sources of honey bee propolis will remain relatively low

Hydrocarbons and monoesters of propolis waxes from Brazil

Waxes of 23 samples of propolis of Apis mellifera mostly from Brazil yielded monoesters as main constituents, followed by hydrocarbons. The methyl and acetyl esters of the carboxylic acids and alcohols, respectively, derived from the monoesters, and the hydrocarbons were analysed by gas chromatography/electron impact-mass spectrometry. The hydrocarbons comprise n-alkanes and alkenes, the main homologues being C 27H56, C29H60, C31H 64 and C33H68. iso-Alkanes in low amounts were found in some samples. The main carboxylic acids are C16:0, C18:0, C18:1. The primary alcohols range from C24 to C34, C30 being generally the main constituent. A wide variation in the distribution of hydrocarbons, acids and alcohols was found comparing one sample with another. The composition of propolis wax is similar to that of comb wax, which suggests that propolis waxes are probably secreted by the bees, rather than originating from plants. © Inra/DIB/AGIB/Elsevier, Pari

Assessment of different seedling production techniques of Euterpe edulis

Euterpe edulis is an endangered species with high importance ecologically and economically. Seedling production seems to be one of the most important alternatives to population recovery. Besides that, the knowledge of seedling production methods' influence over germination is very restricted. Thus, this study aimed to evaluate the effects of parent populations, germination conditions, and the substrate to commercial seedling production of E. edulis. Nine thousand seven hundred and thirteen seeds were distributed between the heated water and control, greenhouse and open-field treatments. The parent population presented high differences between most of the germination indexes. Influencing the germination rate, mean germination time and germination speed, but not affecting synchrony and uncertainty indexes. Heated water treatment did not affect any of the studied indexes, presenting a close pattern of germination over time, indicating it is an appropriate method for seedling production. Greenhouse and open-field treatment presented variations at the same indexes affected in the parent population analysis. The most profitable method for E. edulis seed germination was the greenhouse production method, which provided the best indexes results

Distribution and evolution of secondary metabolites in Eriocaulaceae, Lythraceae and Velloziaceae from "campos rupestres"

Hypotheses are presented on the evolution of structural patterns of secondary metabolites (flavonoids and foliar wax alkanes) and fatty acids of families of "campos rupestres". The distribution of fatty acids is given for genera of Lythraceae, with emphasis on Cuphea (supposedly more advanced) and Diplusodon. Compounds with saturated short chains represent a derived condition in Lythraceae although they are probably restricted to Cuphea. It is suggested that evolution selected for more complex flavonoid patterns in Cuphea, with the inclusion of C-glycoflavones and methoxylated flavonols (rhamnetin and isorhamnetin), which are not found in members of Diplusodon and Lafoensia. The supposedly primitive groups of Eriocaulaceae (e.g., Paepalanthus) presented more complex flavonoid patterns characterized by flavones and flavonols, the latter frequently being 6-hydroxylated or methoxylated. More advanced groups of Eriocaulaceae (e.g., Leiothrix and Syngonanthus) apparently possess only flavones, C-glycoflavones are a salient feature of species with smaller habits. In Velloziaceae, members of the primitive subfamily Vellozioideae show distribution of alkanes of foliar epicuticular wax in which C27, C29 or C31 predominate; members of the derived subfamily Barbacenioideae usually show distributions with a predominance of C33 or C35, while species of Pleurostima (Barbacenioideae) have C31 as the main homologue, thus being intermediate between the two subfamilies. It is suggested that the evolution of alkanes in Velloziaceae follows a trend toward elongation of carbon chains. The condition of advanced or primitive chemical patterns is inferred from the results of cladistic analyses based on morphological characters (Eriocaulaceae and Lythraceae), and morphological and molecular characters (Velloziaceae)

Phylogenetic relationships and infrageneric classification of Epidendrum subgenus Amphiglottium (Laeliinae, Orchidaceae)

Epidendrum L. is the largest genus of Orchidaceae in the Neotropical region; it has an impressive morphological diversification, which imposes difficulties in delimitation of both infrageneric and interspecific boundaries. In this study, we review infrageneric boundaries within the subgenus Amphiglottium and try to contribute to the understanding of morphological diversification and taxa delimitation within this group. We tested the monophyly of the subgenus Amphiglottium sect. Amphiglottium, expanding previous phylogenetic investigations and reevaluated previous infrageneric classifications proposed. Sequence data from the trnL-trnF region were analyzed with both parsimony and maximum likelihood criteria. AFLP markers were also obtained and analyzed with phylogenetic and principal coordinate analyses. Additionally, we obtained chromosome numbers for representative species within the group. The results strengthen the monophyly of the subgenus Amphiglottium but do not support the current classification system proposed by previous authors. Only section Tuberculata comprises a well-supported monophyletic group, with sections Carinata and Integra not supported. Instead of morphology, biogeographical and ecological patterns are reflected in the phylogenetic signal in this group. This study also confirms the large variability of chromosome numbers for the subgenus Amphiglottium (numbers ranging from 2n = 24 to 2n = 240), suggesting that polyploidy and hybridization are probably important mechanisms of speciation within the group.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, FAPESP[03/03063-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, FAPESP[06/55121-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, FAPESP[03/03062-5]Conselho Nacional do Desenvolvimento Cientifico e Tecnologico, CNPq[303962/2004-6]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Year season on epicuticular waxes in leaves of Echinodorus grandiflorus (Cham. & Schltdl.) Micheli (Alismataceae)

The paper aimed to study the influence of different seasons of the year on epicuticular waxes in Echinodorus grandiflorus plants and to analyze the profile of nalkanes in epicuticular waxes. The experiment used adventitious plantlets from the flower stem and approximately 10-cm-tall adventitious plantlets with an average of 4 to 5 leaves, planted in 10-liter pots containing a 40% soil, 40% rice hulls, and 20% vermicompost mixture. E. grandiflorus presented an intermediary profile between terrestrial and aquatic plants, with a main homologue C27 (heptacosane), followed by C25 (pentacosane) and C29 (nonacosane). The studies presented here provide information about ecological aspects and chemical and mechanical defenses of Echinodorus grandiflorus.Este trabalho objetivou estudar a influência das estações do ano sobre o conteúdo de ceras epicuticulares e a análise dos perfis dos n-alcanos da cera em folhas de Echinodorus grandiflorus. No experimento foram utilizadas mudas adventícias com aproximadamente 10 cm de altura e 4 a 5 folhas, que foram plantadas em vasos de 10 L, tendo como substrato a mistura de 40% de terra, 40% de palha de arroz e 20% de húmus de minhoca. Echinodorus grandiflorus apresentou perfil intermediário entre plantas terrestres e aquáticas, apresentando como principal homólogo C27 (heptacosano), seguido de C25 (pentacosano) e C29 (nonacosano). Os estudos realizados fornecem informações sobre os aspectos ecológicos e as defesas químicas e mecânicas de Echinodorus grandiflorus