DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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3 resultados
Resultados da Pesquisa
Item Study of the reproductive biology of an Amazonian Heterotaxis (Orchidaceae) demonstrates the collection of resin‑like material by stingless bees.(2019) Krahl, Amauri Herbert; Holanda, Ana Sofia Sousa de; Krahl, Dayse Raiane Passos; Martucci, Maria Elvira Poleti; Gobbo Neto, Leonardo; Webber, Antonio Carlos; Pansarin, Emerson RicardoTropical and subtropical plants provide to pollinators a range of nutritive and non-nutritive materials as alternative to pollen and nectar, including resins, which are gathered by females of several groups of social and solitary bees. Although resinlike material has previously been recorded in Maxillariinae, these investigations generally did not present data relating to pollinators. In fact, the collection of resins has never been recorded elsewhere in orchids. The aim of this paper was to provide a detailed study of the reproductive biology of an Amazonian Heterotaxis, H. superfua, based on records of fowering phenology, foral morphology, pollinator behavior and breeding system. Heterotaxis superfua ofers resin-like material to pollinators and is pollinated by a single species of stingless bee. The resin is a heterogeneous material rich in mucilage, starch and sugars, while lipoidal substances occur as small droplets. Chemical analyses confrm the presence of sugar, which explain the presence of reducing sugars and mucilage detected in the histochemical investigations. Our data also showed the Heterotaxis is self-compatible and pollinator dependent. This study demonstrates for the frst time the collection of resin-like material in orchids. The gathering of resin is frequently associated with the nest construction, since this material is considered to be a water-repellent and has anti-pathogen chemical properties. Despite ofering of a foral reward, fruit set under natural conditions is lower than for experimental pollinations, suggesting limited pollen fow within the population.Item Comprehensive untargeted metabolomics of Lychnnophorinae subtribe (Asteraceae: Vernonieae) in a phylogenetic context.(2018) Martucci, Maria Elvira Poleti; Loeuille, Benoît Francis Patrice; Pirani, Jose Rubens; Gobbo Neto, LeonardoMembers of the subtribe Lychnophorinae occur mostly within the Cerrado domain of the Brazilian Central Plateau. The relationships between its 11 genera, as well as between Lychnophorinae and other subtribes belonging to the tribe Vernonieae, have recently been investigated upon a phylogeny based on molecular and morphological data. We report the use of a comprehensive untargeted metabolomics approach, combining HPLC-MS and GC-MS data, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. We analyzed 78 species by UHPLC-MS and GC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in MetAlign and in MSClust and the matrices generated were used in SIMCA for hierarchical cluster analyses, principal component analyses and orthogonal partial least square discriminant analysis. The results showed that metabolomic analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels (Lychnophora or Eremanthus). Our results confirm that data generated using metabolomics provide evidence for chemotaxonomical studies, especially for phylogenetic inference of the Lychnophorinae subtribe and insight into the evolution of the secondary metabolites of this group.Item Chemical composition and secretion biology of the floral bouquet in legume trees (Fabaceae).(2018) Marinho, Cristina Ribeiro; Martucci, Maria Elvira Poleti; Gobbo Neto, Leonardo; Teixeira, Simone de PáduaIn the present investigation, we studied the floral bouquet and its associate osmophores in three legume trees using a combination of chemical and ultrastructural analyses, a poorly investigated approach to plant glands. The purpose was to understand the secretory process of osmophores and to identify which of the substances produced are responsible for the attraction of pollinators. Petals from buds and flowers of Bauhinia rufa, Caesalpinia pulcherrima and Hymenaea courbaril were fixed and processed for analysis by transmission electron microscopy. Fresh petals of H. courbaril and C. pulcherrima were also collected, submitted to a headspace solid-phase micro-extraction method and analysed using GC-MS. Typical subcellular features of terpene-secreting osmophores were detected: abundance of mitochondria with conspicuous cristae, plastids with plastoglobuli, rough endoplasmic reticulum and the presence of vesicles and oil droplets in the cytoplasm. Novel subcellular characters of osmophores were detected, such as cellular vacuolation in stages far preceding anthesis and a wealth of dictyosomes. The ultrastructure confirmed that the osmophores produce terpenes and phenolic compounds as previously reported. However, the GC-MS analyses showed that only the terpenes are released and could act on pollinator attraction. The phenolics accumulated are mobilized from these structures and metabolized/reabsorbed by the other plant tissues.