Cianogênese em esporófitos de pteridófitas avaliada pelo teste do ácido pícrico

Abstract

Palavras-chave: metabólitos secundários, plantas tóxicas, ecologia química, monilophyta, licophytaABSTRACT -(Cyanogenesis in sporophytes of pteridophytes evidenced by the picric acid test). Cyanogenic glycosides are defense substances found in some plants that are able to produce cyanhydric acid on hydrolysis. The present work aimed to study the occurrence of cyanogenesis in pteridophytes of rocky areas of Pedra de Itacoatiara, State Park of Serra da Tiririca, Rio de Janeiro State. Nineteen species, distributed in 13 genera and nine families have been analyzed monthly, during one year. In each species, the analysis was carried out on fertile leaves, sterile ones, young leaves (croziers) and stems. Cyanogenesis was evidenced using filter paper embedded with picric acid. Among studied species, 14 were analysed here for the first time, and 14 gave a positive picric test. Our results showed variation along time in the production of cyanhydric acid in the vegetal species and parts. The species, Microgramma vacciniifolia (Langsd. & Fisch.) Copel. (Polypodiaceae) and Pteridium aquilinum (L.) Kuhn var. arachnoideum (Kaulf.) Brade (Dennstaedtiaceae) were cyanogenic all along the studied period.

Aspectos florísticos e econômicos das pteridófitas de um afloramento rochoso do estado do Rio de Janeiro, Brasil

“…Faz parte da composição química de um xarope comercializado em farmácias, indicado para o tratamento de doenças do aparelho respiratório (Santos & Sylvestre 2000). Santos et al (2005) indicam que esta espécie possui atividade cianogênica.…”

Assessment of a subtropical riparian forest focusing on botanical, meteorological, ecological characterization and chemical analysis of rainwater

“…For example, species of the genus Microgramma present a long-crawling rhizome that allows the occupation of extensive areas in the forophytes (Waechter 1998;Kersten and Silva, 2001). Specifically, M. vaccinifolia could have taken the highest IVs due to its aleopathic potential (Peres et al 2009) and this species is cyanogenic, what can be reducing the predation (Santos et al, 2005) and increase its population. Microgramma squamulosa has a high sclerophylly index (Rocha et al, 2013), stomatal density and higher thickness of hypoderm in more polluted environments , and these adaptations are important under water stress (Fahn and Cutler, 1992).…”

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“…For example, species of the genus Microgramma present a long-crawling rhizome that allows the occupation of extensive areas in the forophytes (Waechter 1998;Kersten and Silva, 2001). Specifically, M. vaccinifolia could have taken the highest IVs due to its aleopathic potential (Peres et al 2009) and this species is cyanogenic, what can be reducing the predation (Santos et al, 2005) and increase its population. Microgramma squamulosa has a high sclerophylly index (Rocha et al, 2013), stomatal density and higher thickness of hypoderm in more polluted environments (Rocha et al, 2014), and these adaptations are important under water stress (Fahn and Cutler, 1992).…”