RESUMO
Plant extracts are complex mixtures that are difficult to characterize, and mass spectrometry is one of the main techniques currently used in dereplication processes. Fridericia chica is a species with medicinal uses in Latin American countries, used in the treatment of inflammatory and infectious diseases. Extracts of this plant species are characterized by the presence of anthocyanidins. In this study, using high-resolution mass spectrometry coupled with liquid chromatography, it was possible to determine the molecular formula of thirty-nine flavonoids. Fragmentation analysis, ultraviolet spectrum and nuclear magnetic resonance data allowed the partial characterization of the structures of these compounds. The spectral dataset allowed the identification of a series of flavones in addition to the desoxyanthocyanidins common in extracts of the species. The occurrence of some of the proposed structures is uncommon in extracts of species of the Bignoniaceae family, and they are reported for the first time in the extract of this species. Quantitative analyses of total flavonoids confirmed the high content of these constituents in the species, with 4.09 ± 0.34 mg/g of dry plant material. The extract under study showed low in vitro cytotoxicity with CC50 ≥ 296.7 ± 1.4 µg/mL for Vero, LLC-MK2 and MRC-5 cell lines. In antiviral activity assays, inhibition of the cytopathic effects of Dengue, Zika and Mayaro viruses was observed, with EC50 values ranging between 30.1 and 40.9 µg/mL. The best result was observed against the Mayaro virus, with an EC50 of 30.1 µg/mL.
Assuntos
Bignoniaceae , Flavonas , Infecção por Zika virus , Zika virus , Antocianinas/análise , Antivirais/análise , Antivirais/farmacologia , Bignoniaceae/química , Flavonas/análise , Flavonas/farmacologia , Flavonoides/análise , Flavonoides/farmacologia , Espectrometria de Massas , Extratos Vegetais/química , Folhas de Planta/químicaRESUMO
INTRODUCTION: The methanol (MeOH) leaf extracts of the species Faramea bahiensis, F. hyacinthina and F. truncata (Rubiaceae) have previously shown in vitro non-cytotoxic and anti-dengue virus serotype 2 (DENV2) activities in human hepatocarcinoma cell lineage (HepG2). Chemical studies have led to the isolation of major flavonoids, but quite complex fractions of phenolic compounds still remain. OBJECTIVE: To complete the study of phenolic compounds in the leaves and to access the presence of these compounds in the stems of these Faramea spp. by online high-performance liquid chromatography-diode array detector-electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI-MS/MS), as well as to evaluate the in vitro cytotoxic and anti-DENV2 activities of their MeOH stem extracts. METHODOLOGY: The identification was performed by comparing retention times, UV and mass spectra with those of available standards and by using the mechanisms and fragmentation patterns established in previous studies. The effects of the extracts in DENV2 infected HepG2 cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The virus titer was quantified by plaque assay. RESULTS: The study led to the characterisation of 31 phenolic compounds including flavonoid O- and C-glycosides, phenolic acids and one coumarin. The stem extracts from F. hyacinthina and F. bahiensis presented a similar bioactivity to those of their leaves but a loss of cytoprotective activity of F. bahiensis and a higher cytotoxicity of F. truncata were observed. CONCLUSIONS: This research allowed a detailed phenolic composition of three bioactive Faramea species to be achieved, thus contributing to the study of this genus and providing valuable information for further phytotherapeutic applications.
Assuntos
Antivirais/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Vírus da Dengue/efeitos dos fármacos , Folhas de Planta/química , Caules de Planta/química , Polifenóis/análise , Polifenóis/farmacologia , Rubiaceae/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Brasil , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Flavonoides/análise , Flavonoides/farmacologia , Células Hep G2 , Humanos , Sais de Tetrazólio/química , Tiazóis/químicaRESUMO
The defatted fractions of the Faramea hyacinthina and F. truncata (Rubiaceae) leaf MeOH extracts showed in vitro non-cytotoxic and anti-dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). Submitting these fractions to the developed RP-SPE method allowed isolating the antiviral flavanone (2S)-isosakuranetin-7-O-ß-d-apiofuranosyl-(1â6)-ß-d-glucopyranoside (1) from both species and yielded less active sub-fractions. The new diastereoisomeric epimer pair (2S) + (2R) of 5,3',5'-trihydroxyflavanone-7-O-ß-d-apiofuranosyl-(1â6)-ß-d-glucopyranoside (2a/2b) from F. hyacinthina; the known narigenin-7-O-ß-d-apiofuranosyl-(1â6)-ß-d-glucopyranoside (3) from both species; rutin (4) and quercetin-4'-ß-d-O-glucopyranosyl-3-O-rutinoside (5) from F. hyacinthina, and kaempferol-3-O-rutinoside (6), erythroxyloside A (7) and asperuloside (8) from F. truncata have been isolated from these sub-fractions. Compounds 4 - 8 are reported for the first time in Faramea spp.