Abstract The flavonoids and xanthones present in the ethanol extracts of leaves and stems of Fridericia samydoides showed that anti-dengue activities in vitro were investigated qualitatively by liquid chromatography-ultraviolet-mass spectrometry in series. Nineteen flavones and fifteen xanthones were detected and characterized on the basis of their fragmentation pattern in the positive and negative ion mode tandem mass spectrometry spectra and ultraviolet bands. Acacetin, chrysin, vitexin, isovitexin, orientin, isoorientin, mangiferin, 2’-O-trans-caffeoylmangiferin, 2’-O-trans-coumaroylmangiferin and 2’-O-trans-cinnamoylmangiferin were identified by comparison with authentic samples. The other compounds detected were tentatively assigned by analysis of the spectral data and by comparison with literature reports. In addition, it performed the fractionation of the leaves extract leading to the isolation of mangiferin, isovitexin and isoorientin. All extracts and isolated compounds inhibited the Dengue virus replication cycle with EC50 less than 25.0 µg/mL for extracts and 272.5, 85.6 and 79.3 µg/mL for mangiferin, isovitexin and isoorientin, respectively.

Abstract A phytochemical study of Tecoma genus (Bignoniaceae) was accomplished by antitumor activity of ethanolic extracts. Species of this genus are composed of small shrubs often used as ornamental plants. The Tecoma stans species is used in folk medicine for different purposes. Recent work shows in vitro anticancer activity against human breast cancer. The ethanolic extracts from leaves and trunks of Tecoma casneifolia, T. garrocha, T. stans var. angustata and T. stans var. stans were tested in vitro. The assays used were against line tumor cells by the MTT method and the most active extracts were further studied. In this way, the ethanolic extract from T. stans var. stans trunks presented the higher cytotoxicity against the tumor cell lines studied (CC50 0.02 to 0.55 µg/ml) when compared to the other extracts tested (CC50 0.08 to 200.0 µg/ml). Accordingly, this extract was selected for chromatographic fractionation from which five known lignans were isolated. Further, paulownin, paulownin acetate, sesamin, olivil and cycloolivil were identified using 13C and 1H NMR, IR, UV and spectroscopy and spectrometric MS techniques. These isolated compounds were tested and exhibited CC50 ranging from 13.01 to100.0 µg/ml which is superior to the ethanolic extract of trunk of T. stans.

Malaria is nowadays one of the most serious health concerns in a global scale and, although there is an evident increase in research studies in this area, pointed by the vast number of hits and leads, it still appears as a recurrent topic every year due to the drug resistance shown by the parasite exposing the urgent need to develop new antimalarial medications. In this work, 38 molecules were synthesized via copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) or “click” chemistry, following different routes to produce 2 different organic azides, obtained from a 4,7 dicholoquinoline, reacted with 19 different commercially available terminal alkynes. All those new compounds were evaluated for their in vitro activity against the chloroquine resistant malaria parasite Plasmodium falciparum (W2). The cytotoxicity evaluation was accomplished using Hep G2 cells and SI index was calculated for every molecule. Some of the quinoline derivatives have shown high antimalarial activity, with IC50 values in the range of 1.72-8.66 µM, low cytotoxicity, with CC50>1000 µM and selectivity index (SI) in the range of 20-100, with some compounds showing SI>800. Therefore, the quinolinotriazole hybrids could be considered a very important step on the development of new antimalarial drugs.

Due to the increase of bacterial resistance, the search for new antibiotics is necessary and the medicinal plants represent its most important source. The aim of this study was to evaluate the antibacterial property of extract and fractions from Protium spruceanum leaves, against pathogenic bacteria. By means of diffusion and microdilution assays, the crude extract was active against the nine bacteria tested being the hydromethanolic fraction the most active. During phytochemical procedures, procyanidin (1) and catechin (2) were identified as the main antibacterial constituents of this fraction. In silico results obtained using PASSonline tool indicated 1 and 2 as having good potential to interact with different targets of currently used antibiotics. These results no indicated potential to none DNA effect and indicated the cell wall as mainly target. Electrophoresis result supported that had no DNA damage. Cell wall damage was confirmed by propidium iodide test that showed increased membrane permeability and by cell surface deformations observed in scanning electronic microscopy. The in vitro assays together with the in silico prediction results establish the potential of P. spruceanum as source of antibacterial compounds that acts on important bacterial targets. These results contribute to the development of natural substances against pathogenic bacteria and to discovery of new antibiotics.

Resumo A espécie Cissus erosa (Vitaceae) conhecida popularmente, no Brasil, como Cipó fogo é uma planta medicinal empregada no tratamento de verrugas e úlceras externas. O presente estudo objetivou a avaliação da atividade antiviral frente a Dengue e Zika virus dos extratos etanólicos de caules e de folhas desta espécie pelo método colorimétrico do MTT e determinar a caracterização fitoquímica por cromatografia líquida de ultra eficiência acoplada a espectrometria de massa destes extratos (CLUE-EM). Os extratos apresentaram atividade antiviral e baixa citotoxicidade. O extrato de folhas apresentou CC50 > 500 µg/ml para células LLCMK2 e CE50 = 18,2 µg/mL, IS > 27,5 contra o Dengue virus 2 (DENV 2). Ambos os extratos (caules e folhas) apresentaram atividade anti-Zika virus com CE50 de 45,8 µg/ml e 82,8 µg/ml, respectivamente. Os extratos apresentaram CC50 de 309,2 µg/ml (folhas) e 387,6 µg/ml (caules) para células Vero. Nas análises por CCD e CLAE-DAD detectou-se a presença de triterpenos, esteroides, flavonoides e taninos. Análises por CLUE-EM dos extratos permitiram a identificação parcial dos flavonoides majoritárias destes extratos como sendo, vitexina, isovitexina, orientina, isoorientina, luteolina-7,4’-di-O-glicosilflavona, metoxiluteolia-6(8)-C-hexosil. Os resultados dos estudos fitoquímicos até o momento sugerem que flavonoides e terpenoides são os constituintes majoritários dos extratos etanólicos destas espécies e devem contribuírem para a atividade antiviral observada in vitro.

Abstract Cissus erosa (Vitaceae), popularly known in Brazil as Cipó-fogo, is a medicinal plant used in the treatment of warts and external ulcers. The present study aimed to evaluate the activity of stems and leaves ethanol extracts of C. erosa against the Dengue and Zika virus by the MTT colorimetric method and to carry on the phytochemical characterization of active extracts by high performance liquid chromatography coupled to mass spectrometry (UPLC-MS). Only the leaves ethanol extract showed anti-Dengue virus activity EC50 18.2 µg/ml (SI > 27.5) and low cytotoxicity for LLCMK2 cells (CC50 > 500 mg/ml). Both extracts (stems and leaves) showed anti-Zika virus activity with EC50 of 45.8 mg/ml and 82.8 mg/ml, respectively. These extracts presented CC50 of 309.2 µg/ml (leaves) and 387.6 µg/ml (stems) to Vero cells. Analysis by CCD and HPLC-DAD detected the presence of triterpenes, steroids, flavonoids and tannins. UPLC-MS analyses of these extracts, allowed the identification of the majority of flavonoids present known as vitexin, isovitexin, orientin, isoorientin and two flavones derivatives, methoxyluteolin-6(8)-C-hexosyl and luteolin-7,4’-di-O-glycosylflavone. The results of the phytochemical studies here described suggest that flavonoids and terpenoids are the substances that contribute to the antiviral activity of the ethanol extracts within this species.

Extratos etanólicos de dezoito espécies vegetais pertencentes à família Bignoniaceae, das quais sete são descritas como de uso medicinal, foram avaliados, pelo ensaio colorimétrico do MTT, para atividades citotóxica, em células Vero, e antiviral, frente aos vírus herpes simplex-tipo 1, vaccinia e encefalomiocardite murina. A maior parte dos extratos não apresentou citotoxicidade até a concentração de 500 μg/mL. Dos 28 extratos testados quatorze (50%) apresentaram atividade antiviral com valores de CE50 na faixa de 4,6+03 a 377,2+17,7 μg/mL. Somente duas espécies, Arrabidaea samydoides e Callichlamys latifolia, foram ativas frente aos três vírus. Os extratos foram caracterizados pelos seus perfís cromatográficos em CCD e CLAE-FR. Análises por CLAE-FR mostraram que a mangiferina é o constituinte majoritário em A. samydoides mas a substância isolada foi menos ativa do que o extrato bruto. Esta é a primeira vez que se relata a atividade antiviral de extratos das dezoito espécies avaliadas.

Ethanol extracts of eighteen Bignoniaceae species have been evaluated by the MTT assay for cytotoxicity in Vero cells and for antiviral activity against Human herpes virus type 1, Vaccinia virus and murine Encephalomyocarditis virus. Among such species, seven are reported to be of traditional medicinal use No cytotoxicity was observed for most of the extracts up to the concentration of 500 μg/mL. Fourteen (50%) of the 28 extracts assayed have disclosed antiviral activity with EC50 values in the range of 4.6+0.3 to 377.2+17.7 μg/mL. Only two species, Arrabidaea samydoides and Callichlamys latifolia, have shown activity against all the three viruses. The extracts were chemically characterized by their TLC and HPLC-DAD profiles. Mangiferin is the major constituent of A. samydoides but the isolated compound has been less active than the crude extract. This is the first report on the antiviral evaluation of the eighteen Bignoniaceae species assayed.