Anatomia, histoquímica e prospecção fitoquímica do caule de Tynanthus fasciculatus Miers (Bignoniaceae)

• Autor(a) principal: Nascimento, Leonor Monteiro do
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2497
• topic: Planta medicinal; Anatomia; Fitoquímica; Medicinal Plant; Anatomy; Phytochemistry; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

Tynanthus fasciculatus Miers (Bignoniaceae), commonly known as cipó-cravo, is a vine with a characteristic smell of clove, used in the traditional medicine and presents pharmacological action proved by its antimalaric, anti- inflammatory and its bactericide properties. The goals of this work were to characterize anatomically the development of the stem of T. fasciculatus and to associate the structure of the bark with the presence of chemical groups of pharmacological interest. Concerning the structural analyses, portions of the stem from different stages of development were processed according to the usual techniques under light and scanning electron microscopies. With regard to histochemical analysis, transversal sections from the bark were submitted to several stains and reagents. For the phytochemical prospection, the hexanic and methanolic extracts from the bark were submitted to the study through thin layer chromatography (TLC). The stem cambial activity begins precociously, forming a mass of usual secondary xylem around the medulla. The phellogen begins from a subepidermal collenchyma layer, persisting during the stem development. Until this stage, the secondary growth may be considered usual. Posteriorly, four portions of the cambial zone, opposed to each other, by pairs, decrease drastically the production of secondary xylem to the inside and begin the production of great quantity of secondary phloem to the outside. From this stage, the secondary growth was considered unusual, and both the secondary xylem and secondary phloem present conductive cells of high calibre. Subsequently, there come new portions of the cambial zone with unusual activity, adjacent to those already established, giving to the xylem mass a aspect of Maltese cross. The xylem presents vessels arranged in tangential strips. There is predominance of wide and short vessel elements, with bordered pits and simple perforation plates, frequently obliterated by tyloses. The axial parenchyma is a banded parenchyma type, delimited by fibres. The rays are homocellular and multiseriate. The secondary phloem inserted in the xylem mass presents the predominance of sieve elements with compound sieve plates, associated to a little amount of axial parenchyma, arranged in strips alternated with fibers and uniseriate rays. In the bark, the secondary phloem presents inconspicuous sieve elements associated with a great amount of axial parenchyma, forming strips alternated with fibre-sclereids. The ray also are homocellular and multiseriate. The cortex is kept next to the periderm, and the phellogen activity is persistent, constituting a periderm with multistratified phelloderm, suber and lenticels. The main compound groups identified by both techniques are phenolic compounds, alkaloids and terpenes, all situated in the parenchymatous cells of the bark and the unusual secondary phloem inserted in the xylem mass. The tannins and saponis were identified only through TLC. The structural characterization of the stem and the histolocalization and the chemical identification of the compounds of the secondary metabolism in the T. fasciculatus stem give us a subsidy to use the bark as vegetal drug and contribute with more data to the already existent monograph in the Brazilian Pharmacopoeia.