Anatomia de folha e caule e quantificação espectrofotométrica de fenóis totais e taninos da erva-de-bicho (Polygonum acre Kunth var. aquatile Meisn.)

Abstract

-(Leaf and stem anatomy and spectrophotometric quantification of total phenolics and tannins of erva-de-bichoPolygonum acre Kunth var. aquatile Meisn.). Polygonum acre Kunth var. aquatile Meisn., a medicinal plant, was studied with the purpose of selecting useful characteristics for fragmented plant identification as well as to contribute to the botanical study of the species. Usual anatomical analysis was used and total phenolics, condensed and galic tannins were quantified. The comparison with bibliographic data allowed to select some characteristics to help the identification of P. acre: 1) absence of well defined endodermis with Casparian strips on the stem in accordance with others species of the Polygonum genus; 2) numerous multicellular trichomes on the ocrea and secretory cavities only in abaxial epidermis; 3) fibers on the interior of the xylem from the stem; 4) inverted bundle in midrib and 5) lignified protuberances in the edge of the leaf. The quantification of total phenolics and tannins from P. acre shows remarkable amounts of condensed tannins, but no hydrolysable tannins were detected.Key words -condensed tannins, erva-de-bicho, medicinal plant, pharmacognosy, Polygonaceae RESUMO -(Anatomia de folha e caule e quantificação espectrofotométrica de fenóis totais e taninos da erva-de-bichoPolygonum acre Kunth var. aquatile Meisn.). Com o objetivo de selecionar caracteres úteis na identificação de Polygonum acre Kunth var. aquatile Meisn., erva medicinal geralmente comercializada sob a forma de planta fragmentada, e para contribuir para o conhecimento botânico da espécie, descreveu-se sua anatomia e quantificaram-se os fenóis totais, taninos gálicos e condensados. O material foi processado segundo técnicas usuais de anatomia vegetal. Na análise anatômica, a comparação dos resultados com a bibliografia permitiu selecionar os seguintes caracteres como auxiliares à determinação de P. acre: 1) ausência de endoderme bem definida com estrias de Caspary conforme descrito para outras espécies do gênero Polygonum; 2) ócrea com numerosos tricomas pluricelulares e cavidades secretoras localizadas apenas na face abaxial da epiderme; 3) fibras presentes internamente ao xilema do caule; 4) feixe invertido na nervura principal; e 5) presença de pêlos lignificados no bordo da folha. As dosagens de fenóis totais e taninos demonstraram que a planta apresenta quantidade significativa de taninos condensados e que a princípio, os taninos gálicos não estão presentes na espécie.

Seasonal Variation in the Content of Condensed Tannins in Leaves of Xylopia emarginata Mart. (Annonaceae) in Response to Phenology and Climate

“…Plant species are dynamic organisms, whose accumulation of phenolic compounds varies with seasonality (Lima et al, 2009), depending on intrinsic (genetic) and extrinsic (environmental) factors (Frantianni et al, 2007) and varies with different seasons (Bussotti et al, 1998;Ma et al, 2003;Brooks & Feeny, 2004). Thus, studies on the seasonal variation of phenolic compounds indicate that the climatic changes that occur during an annual cycle, notably those related to precipitation and temperature, influence the phenotypic changes in plants that alter their production pattern of phenolic compounds to suit situations of water stress (Ma et al, 2003;Brooks & Feeny, 2004).…”

A first approach for the micropropagation of the medicinal halophyte Polygonum maritimum L. and phenolic profile of acclimatized plants

“…aquatile (Mart.) Mesisn, and among the different growth regulators tested, the combination of 0.06 mg/L BA + 0.24 mg/L NAA promoted the highest development of shoots and elongation (2.82 per explant), and no treatment was necessary for rooting (De Lima et al, 2010). Also, Hasan and Sikdar (2010) obtained the highest shoot development of P. hydropiper L. (9.0 per explant) when they were cultivated in MS medium supplemented with 2.0 mg/L KIN (Hasan and Sikdar, 2010).…”

“…Shoots generated from disinfected explants were divided into four groups for subcultivation: (1) MS basal medium free of PGRs, (2) MS medium supplemented with 0.06 mg/L of BA and 0.24 mg/L of NAA (De Lima et al, 2010), (3) MS medium supplemented with 3 mg/L of BA and 0.1 mg/L of IAA (Das and Handique, 2002), and (4) MS medium supplemented with 2 mg/L of KIN (Hasan and Sikdar, 2010). Cultures were maintained for 60 days or until enough shoots were available to establish the experiments.…”

“…The amount and quality of the produced bioactive natural compounds are dependent on several factors, including genotype, and thus, plant tissue culture techniques, such as in vitro micropropagation, may contribute to obtaining genetically similar plants with standardized contents of bioactive metabolites of selected plants (Espinosa-Leal et al, 2018;Akin, 2020). Such tools allow producing high-yielding clones for industrial applications, running as a nursery for producing stock plants for ensuring the supply of high-scale greenhouse cultivation of selected medicinal plants producing high-quality bioactive ingredients for harmonized commercial products (De Lima et al, 2010;Moraes et al, 2021).…”

“…aquatile (Mart.) Meisn (De Lima et al, 2010), Polygonum hydropiper L. (Hasan and Sikdar, 2010), Polygonum microcephallum D.Don. (Das and Handique, 2002), Polygonum multiflorum Thunb.…”