Alcaloides de Selaginella convoluta: investigação química e do potencial antifúngico

Abstract

Selaginella convoluta is native from Brazil semi-arid and has shown interesting use in folk medicine, therefore there is a potentiality of obtaining bioactive molecules from this species. The aim of this study is the phytochemistry of S. convoluta by structural identification of its alkaloids, as well as an investigation of the metabolism in the dry and irrigated conditions. Also, biological potential of the enriched fraction of alkaloids against yeast was evaluated. The NMR technique was used for structure elucidation and analysis of the metabolic fingerprint. NMR spectra of the metabolic fingerprint analysis were analyzed according to Pearson correlation. The metabolites identified in metabolic fingerprint analysis that demonstrated to be interesting under the point of view of the biosynthesis are inositol and glutamate. Inositol appears to be more present in irrigated condition and has zero correlation coefficient, which indicates a significant difference between the analyzed conditions, according to the Pearson correlation. Inositol can be combined with auxin, allowing the long-distance transport within the plant. Whereas glutamate appear to be more present in the dry condition, having a coefficient 0.5 ≤ or <0.8, indicating a moderate correlation. The glutamate has an important role in communications over long distances, being a precursor of substances such as proline, GABA and polyamines, substances involved in drought tolerance and which has an important role in the stress response in plants. On this way, inositol and glutamate demonstrated importance from the point of view of the biosynthesis, once may to be involved in the communication between the roots and the aerial parts of S. convoluta. Furthermore, anabasine, a pyridine alkaloid was identified for the first time in Selaginellaceae, and also in pteridophytes. The anabasine presented potential antifungal properties against Candida krusei and Cryptococcus neoformans.