Caracterização estrutural, fitoquímica e atividade biológica de extratos foliares de espécies de Palicourea Aubl. (Rubiaceae) da Mata Atlântica

• Autor(a) principal: Alexandrino, Camilla Ribeiro
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7906
• topic: Leaf anatomy; Ultrastructure; Palicoureeae; Chemical composition; Anatomia foliar; Ultraestrutura; Palicoureeae; Composição química; Rubiacea - Rio de Janeiro (RJ); Palicourea; Plantas medicinais; Mata Atlântica; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

Palicourea is a Neotropical genus of predominantly shrubs and subshrubs and is most diverse in South and Central America. In Brazil, the genus is represented by 56 species and 6 subspecies, which occur mainly in the Amazon Forest, Atlantic Forest and the Cerrado. The objective of the present study was to compare the anatomy and micromorphology of the leaves of six species of Palicourea from the Atlantic Forest, and discuss the importance of these parameters to the taxonomy and ecology of the genus. The toxic effects of the leaf extracts of P. marcgravii; P. rudgeoides and P. tetraphylla against the epimastigote form of T. cruzi, and antifungal activity against C. albicans, C. tropicalis and F. solani, were tested. Additionally, the study aimed to identify micromolecules of the extracts in order to corroborate the phytochemical and chemotaxonomical profile of the genus. The plant material was collected from sites in Atlantic Forest in southeastern Brazil. Preparation of the samples followed standard techniques for light, scanning electron and transmission electron microscopy and histochemical tests. Leaf extracts were obtained by rotary evaporation followed by fractioning and used in tests antifungal, antiparasitic activity and chemical prospecting. The general anatomical characteristics observed were: the presence of unicellular, tector trichomes; hypostomatic leaf blades; paracytic and parallelocytic stomata; uniseriate epidermis; papillae and idioblasts containing bundles of raphides. Histochemical tests revealed the presence of lipid, starch, lignin and a pectin compound. Statistical analyses segregated the species according to leaf structure and inferred an affinity among the analyzed species. These analyses also documented the phenotypic plasticity of the leaves. The biological tests revealed a considerable effect of the extract on the epimastigote of T. cruzi, but none of the tested extracts were able to inhibit the growth of the yeasts C. albicans and C. tropicalis or the filamentous fungus F. solani. The resonance spectra revealed the presence of coumarins in the ethyl acetate extract of P. rudgeoides, and the chematographic plates indicated their possible presence in P. marcgravii and P. tetraphylla as well. The chemotaxonomic profile revealed a tendency toward the production of iridoid alkaloid in Palicourea. These results show the potential of the anatomical and chemical characterization of leaves for the circumscription of Palicoureeae, and corroborate the systematic of Rubiaceae indicating anatomical and chemical trends for the tribe