Resumo A família Asteraceae figura como um interessante alvo para a busca de alternativas naturais para proteção das safras. Muitas espécies da família Asteraceae crescem como plantas daninhas, e são capazes de influenciar o desenvolvimento de outras espécies através do fenômeno de alelopatia. Sendo assim, o propósito desta revisão é investigar na literatura os principais gêneros e espécies da família Asteraceae envolvidos com potencial alelopático ou fitotóxico, bem como as classes de metabólitos secundários responsáveis por tal atividade. Artemisia, Ambrosia, Bellis, Bidens, Helianthus e Tagetes foram identificados como os principais gêneros com atividade alelopática ou fitotóxica. Dentre os metabólitos secundários da família, terpenos, poliacetilenos, saponinas, lactonas sesquiterpênicas, ácidos fenólicos e flavonoides foram descritos como os responsáveis pela inibição do desenvolvimento de outras espécies vegetais. Além disso, o potencial fitotóxico de Acmella oleracea e Sphagneticola trilobata contra as espécies daninhas Calopogonium mucunoides e Ipomoea purpurea foi descrito pela primeira vez. Na concentração de 0,2 mg/mL, todas as frações de A. oleracea inibiram acima de 60% do crescimento das raízes de C. mucunoides. E o extrato hidroalcóolico e as frações de S. trilobata, com exceção da hexânica, afetaram significativamente o crescimento das raízes de I. purpurea, com variação do efeito de inibição de 38 ± 14% a 59 ± 8%, em diferentes concentrações (0,19 mg/mL a 1,13 mg/mL).

Abstract Asteraceae family is as an interesting target for researching natural alternatives for crop protection. Many species from this family grow as weeds, and some of them can influence the development of other species by the allelopathy phenomenon. This paper aimed to review the literature for the main genera and species of the Asteraceae family with allelopathic or phytotoxic potential, as well as the classes of secondary metabolites present in this family and responsible for such activity. Artemisia, Ambrosia, Bellis, Bidens, Helianthus and Tagetes were identified as the main genera with phytotoxic or allelopathic activity. Among the secondary metabolites from this family, terpenes, polyacetylenes, saponins, sesquiterpene lactones, phenolic acids and flavonoids were described as responsible for inhibiting the development of other species. In addition, the phytotoxic potential of Acmella oleracea and Sphagneticola trilobata against the weeds Calopogonium mucunoides. and Ipomoea purpurea was described for the first time. At 0.2 mg/mL, crude extract and fractions of A. oleracea inhibited above 60% of C. mucunoides root growth. Hydroalcoholic extract and fractions of S. trilobata, except hexane, significantly affected I. purpurea root growth, ranging from 38 ± 14% to 59 ± 8% of inhibitory effect at different concentrations (0.19 mg/mL to 1.13 mg/mL).

Mandevilla guanabarica é uma planta endêmica do Brasil, com potencial farmacológico e ornamental inexplorados. Este estudo estabeleceu um eficiente meio de cultura para manutenção da planta in vitro e eficazes protocolos de regeneração e calogênese a partir de diferentes explantes. O meio para plantas lenhosas suplementado com o dobro da concentração de boro (WPM B) e com 2,27 µM de thidiazuron ou 0,49 µM 2-isopenteniladenina proporcionou taxas de multiplicação maiores que 1:6. Os brotos foram 100% enraizados em WPM B, com 83% de sobrevivência após aclimatização. Na calogênese, o meio MS suplementado com altas concentrações de picloram ou ácido 2,4-diclorofenoxiacético produziu, respectivamente, calos não morfogênicos friáveis ou compactos. Este protocolo de micropropagação permite a produção de mudas de M. guanabarica para uso ornamental, comercial e com finalidades de conservação; os calos podem ser utilizados para o estabelecimento de culturas em suspensão na prospecção de compostos bioativos.

Mandevilla guanabarica is an endemic plant from Brazil, with pharmacological and ornamental potential, both unexplored. This study established the best culture medium for in vitro plant maintenance, efficient protocol for its regeneration, and callogenesis from different explants excised from in vitro-grown plants. Woody plant medium with double boron concentration (WPM B) plus 2.27 µM thidiazuron or 0.49 µM 2-isopentenyladenine provided multiplication rates higher than 1:6. Shoots were 100% rooted on WPM B. After acclimatization, plants showed 83% survival. For callogenesis, the use of MS media supplemented with high concentrations of picloram or 2,4-dichlorophenoxyacetic acid produced, respectively, friable or compact non-morphogenic calluses from different types of explants. This micropropagation protocol allows the production of seedlings of M. guanabarica for ornamental or commercial uses, and for conservation purposes; calluses can be used to establish suspension cultures in prospecting for bioactive compounds.

The present study aimed to investigate the in vitro effects of isoschaftoside isolated from Syngonium podophyllum on pig kidney Na+,K+-ATPase. The Na+, K+-ATPase activity was determined by colorimetric measurement of inorganic phosphate (Pi), resulting from ATP hydrolysis. Isoschaftoside significantly decreased the renal Na+, K+-ATPase activity at the highest concentration as well as at a lower concentration. Our work suggests that isoschaftoside is a promising compound for the treatment of hypertension.

This work describes the phytochemical study of the methanol extract obtained from leaves of Guarea macrophylla, leading to the isolation and identification of three flavonoid glycosides (quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-b-D-galactopyranoside, kaempferol 7-O-β-D-glucopyranoside) and a neolignan glucoside, dehydrodiconiferyl alcohol-4-β-D-glucoside. All compounds were identified by a combination of spectroscopic methods (¹H, 1D, 2D NMR, 13C and UV), ESI-MS and comparison with the literature data. This is the first report of flavonoids in the genus Guarea and of a neolignan glucoside in the Meliaceae family.

O fracionamento do extrato etanólico de Piper nigrum biomonitorado por ensaios em larvas de Aedes aegypti resistentes a piretróides resultou no isolamento das amidas larvicidas piperoleína-A e piperina. Comparando-se os valores de CL50, o extrato etanólico (0. 98ppm) foi o mais tóxico, seguido pela piperoleína-A (1. 46ppm) e piperina (1. 53ppm).

Fractionation of Piper nigrum ethanol extract, biomonitored by assays on pyrethroid-resistant Aedes aegypti larvae yielded isolation of the larvicidal amides piperolein-A and piperine. Comparing LC50 values, the ethanol extract (0. 98 ppm) was the most toxic, followed by piperolein-A (1. 46ppm) and piperine (1. 53ppm).

The bioassay-guided fractionation of the hexane extract obtained from the medicinal plant Myroxylon balsamum (red oil) was conducted in preparative thin layer chromatography on silica gel. The obtained fractions and some terpenoids and phenylpropanoids were assayed as larvicidal on third instar Aedes aegypti larvae, NPPN colony. The results indicate that the sesquiterpene nerolidol was the active constituent in the extract and that the sesquiterpenes were more active than the monoterpenes and phenylpropanoids utilized in this study. Lipophilicity seems to be an important property for the activity since the compounds with hydroxyl, carbonyl and methoxyl groups were less active. The results confirm also that essential oils can be a good tool for the control of dengue.