RESUMO
In this work, two neolignans - dehydrodieugenol (1) and dehydrodieugenol B (2) - were isolated from leaves of Ocotea cymbarum (H. B. K.) Ness. (Lauraceae). When tested against two human breast cancer cell lines (MCF7 and MDA-MB-231), compound 1 was inactive (IC50 > 500 µM) whereas compound 2 displayed IC50 values of 169 and 174 µM, respectively. To evaluate, for the first time in the literature, the synergic cytotoxic effects of compounds 1 and 2 with ion Cu2+, both cell lines were incubated with equimolar solutions of these neolignans and Cu(ClO4)2·6H2O. Obtained results revealed no differences in cytotoxicity upon the co-administration of compound 2 and Cu2+. However, the combination of compound 1 and Cu2+ increases the cytotoxicity against MCF7 and MDA-MB-231 cells, with IC50 values of 165 and 204 µM, respectively. The activity of compound 1 and Cu2+ in MCF7 spheroids regarding the causes/effects considering the tumoral microenvironment were accessed using fluorescence staining and imaging by fluorescence microscopy. This analysis enabled the observation of a higher red filter fluorescence intensity in the quiescence zone and the necrotic core, indicating a greater presence of dead cells, suggesting that the combination permeates the spheroid. Finally, using ICP-MS analysis, the intracellular copper disbalance caused by mixing compound 1 and Cu2+ was determined quantitatively. The findings showcased a 50-fold surge in the concentration of Cu2+ compared with untreated cells (p > 0.0001) - 18.7 ng of Cu2+/mg of proteins and 0.37 ng of Cu2+/mg of protein, respectively. Conversely, the concentration of Cu2+ in cells treated with compound 1 was similar to values of the negative control group (0.29 ng of Cu2+/mg of protein). This alteration allowed us to infer that compound 1 combined with Cu2+ induces cell death through copper homeostasis dysregulation.
Assuntos
Neoplasias da Mama , Cobre , Humanos , Cobre/química , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Morte Celular/efeitos dos fármacos , Eugenol/análogos & derivados , Eugenol/farmacologia , Eugenol/química , Folhas de Planta/química , Células MCF-7 , Lignanas/farmacologia , Lignanas/químicaRESUMO
Chagas disease is a neglected tropical disease that affects more than 8 million people. Although there are therapies against this disease, the search for new drugs is important because the current treatments show limited effectiveness and high toxicity. In this work, eighteen dihydrobenzofuran-type neolignans (DBNs) and two benzofuran-type neolignans (BNs) were synthesized and evaluated against amastigote forms of two Trypanosoma cruzi strains. The in vitro cytotoxicity and hemolytic activity of the most active compounds were also evaluated and their relationships with T. cruzi tubulin DBNs were investigated by an in silico approach. Four DBNs demonstrated activity against the T. cruzi Tulahuen lac-Z strain (IC50 from 7.96 to 21.12 µM), and DBN 1 exhibited the highest activity against the amastigote forms of the T. cruzi Y strain (IC50 3.26 µM). Compounds 1-4 showed CC50 values higher than antitrypanosomal activities, except for DBN 3. All DBNs with antitrypanosomal activity demonstrated CH50 higher than 100 µM. The in silico results indicated that DBNs 1, 2, and 4 are capable of destabilizing the dynamics of the tubulin-microtubule from the vinca site. These compounds displayed promising in vitro activity against T. cruzi, especially compound 1, and can be considered molecular prototypes for the development of new antiparasitic drugs.
RESUMO
In this study, five neolignans were isolated from Saururus cernuus-threo-dihydroguaiaretic acid (1), threo-austrobailignan-6 (2), threo-austrobailignan-5 (3), verrucosin (4), and saucernetin (5)-and have their cytotoxic effects evaluated in prostate cancer cell lines (PC3 and DU145). Initially, using an in silico approach, tested compounds were predicted to be absorbed by the gastrointestinal tract, be able to permeate the blood-brain barrier and did not show any alert in PAINS (pan-assay structures interference). In vitro assays showed that compounds 2, 4, and 5 reduced cell viability of DU145 cell line at 100 µmol/L after 48 h while compounds 1 and 3 showed to be inactive at the same conditions. Furthermore, compounds 4 and 5 reduced cell number as early as in 24 h at 50 µmol/L and compound 2 showed effects at 100 µmol/L in 24 h against both cancer cell lines PC3 and DU145. Studies using flow cytometry were conducted and indicated that compound 4 induced strong necrosis and apoptosis whereas compound 5 induced strong necrosis. Otherwise, less active compound 2 did not show evidence of induction of apoptosis or necrosis, suggesting that its mechanism of action involves inhibition of cell proliferation. In conclusion, compounds 4 and 5 have been shown to be promising cytotoxic agents against prostate cancer cell lines and can be used as a starting point for the development of new drugs for the treatment of prostate cancer.
Assuntos
Antineoplásicos , Lignanas , Neoplasias da Próstata , Saururaceae , Masculino , Humanos , Saururaceae/química , Lignanas/farmacologia , Lignanas/uso terapêutico , Antineoplásicos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Apoptose , Linhagem Celular Tumoral , Necrose/tratamento farmacológicoRESUMO
In the present work, dehydrodieugenol B (1) and its methyl ether (2), isolated from Nectandra leucantha twigs, were used as starting material for the preparation of two new derivatives (1a and 2a) containing an additional methoxycarbonyl unit on allyl side chains. Compounds 1a and 2a demonstrated activity against trypomastigotes (EC50 values of 13.5 and 23.0 µM, respectively) and against intracellular amastigotes (EC50 values of 10.2 and 6.1 µM, respectively). Additionally, compound 2a demonstrated no mammalian cytotoxicity up to 200 µM whereas compound 1a exhibited a CC50 value of 139.8 µM. The mechanism of action studies of compounds 1a and 2a demonstrated a significant depolarization of the plasma membrane potential in trypomastigotes, followed by a mitochondrial membrane potential collapse. Neither calcium level nor reactive oxygen species alterations were observed after a short-time incubation. Considering the potential of compound 2a against T. cruzi and its simple preparation from the natural product 2, isolated from N. leucantha, this compound could be considered a new hit for future drug design studies in Chagas disease.
Assuntos
Produtos Biológicos , Doença de Chagas , Trypanosoma cruzi , Anisóis/metabolismo , Produtos Biológicos/metabolismo , Cálcio/metabolismo , Membrana Celular/metabolismo , Humanos , Potencial da Membrana Mitocondrial , Espécies Reativas de Oxigênio/metabolismo , Trypanosoma cruzi/metabolismoRESUMO
Schistosomiasis is a parasitic disease that is part of the neglected tropical diseases (NTDs), which cause significant levels of morbidity and mortality in millions of people throughout the world. The enzyme purine nucleoside phosphorylase from Schistosoma mansoni (SmPNP) represents a potential target for discovering new agents, and neolignans stand out as an important class of compounds. In this work, molecular modeling studies and biological assays of a set of neolignans were conducted against the PNP enzymes of the parasite and the human homologue (HssPNP). The results of the molecular docking described that the neolignans showed good complementarity by the active site of SmPNP. Molecular dynamics (MD) studies revealed that both complexes (Sm/HssPNP - neolignan compounds) were stable by analyzing the root mean square deviation (RMSD) values, and the binding free energy values suggest that the selected structures can interact and inhibit the catalytic activity of the SmPNP. Finally, the biological assay indicated that the selected neolignans presented a better molecular profile of inhibition compared to the human enzyme, as these ligands did not have the capacity to inhibit enzymatic activity, indicating that these compounds are promising candidates and that they can be used in future research in chemotherapy for schistosomiasis.Communicated by Ramaswamy H. Sarma.
Assuntos
Lignanas , Esquistossomose , Animais , Inibidores Enzimáticos/química , Humanos , Simulação de Acoplamento Molecular , Purina-Núcleosídeo Fosforilase/química , Purina-Núcleosídeo Fosforilase/metabolismo , Schistosoma mansoni/metabolismoRESUMO
In the present study, the phytochemical study of the n-hexane extract from flowers of Nectandra leucantha (Lauraceae) afforded six known neolignans (1-6) as well as one new metabolite (7), which were characterized by analysis of NMR, IR, UV, and ESI-HRMS data. The new compound 7 exhibited potent activity against the clinically relevant intracellular forms of T. cruzi (amastigotes), with an IC50 value of 4.3 µM and no observed mammalian cytotoxicity in fibroblasts (CC50 > 200 µM). Based on the results obtained and our previous antitrypanosomal data of 50 natural and semi-synthetic related neolignans, 2D and 3D molecular modeling techniques were employed to help the design of new neolignan-based compounds with higher activity. The results obtained from the models were important to understand the main structural features related to the biological response of the neolignans and to aid in the design of new neolignan-based compounds with better biological activity. Therefore, the results acquired from phytochemical, biological, and in silico studies showed that the integration of experimental and computational techniques consists of a powerful tool for the discovery of new prototypes for development of new drugs to treat CD.
Assuntos
Produtos Biológicos/farmacologia , Doença de Chagas/tratamento farmacológico , Simulação por Computador , Descoberta de Drogas , Lauraceae/química , Lignanas/farmacologia , Tripanossomicidas/farmacologia , Animais , Fibroblastos/efeitos dos fármacos , Rim/efeitos dos fármacos , Macaca mulatta , Camundongos , Camundongos Endogâmicos BALB C , Compostos Fitoquímicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Dehydrodieugenol B and five related natural neolignans were isolated from the Brazilian plant species Nectandra leucantha. Three of these compounds were shown to be active against murine (B16F10) and human (A2058) melanoma cells but non-toxic to human fibroblasts (T75). These results stimulated the preparation of a series of 23 semi-synthetic derivatives in order to explore structure-activity relationships and study the biological potential of these derivatives against B16F10 and A2058 cell lines. These structurally-related neolignan derivatives were analyzed by multivariate statistics and machine learning, which indicated that the most important characteristics were related to their three-dimensional structure and, mainly, to the substituents on the neolignan skeleton. The results suggested that the presence of hydroxyl or alkoxyl groups at positions 3, 4 and 5 (with appropriate sidechains) promoted an increase in electropological and charge density, which seem to be important for biological activity against murine (B16F10) and human (A2058) melanoma cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Desenho de Fármacos , Lignanas/farmacologia , Animais , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Lignanas/síntese química , Lignanas/química , Aprendizado de Máquina , Camundongos , Estrutura Molecular , Análise Multivariada , Relação Estrutura-AtividadeRESUMO
Several species of rapidly growing mycobacteria (RGM) have been associated with biofilms in areas such as biomedical devices, water distribution systems, cosmetic surgery, and catheter-related blood infections. Biofilms which exhibit antimicrobial resistance such as those formed by the genus Mycobacterium pose a significant risk to health and are of particular interest to researchers. Licarin A (a neolignan found in numerous plant species e.g. nutmeg) has been reported to show a wide range of biological actions including anti-inflammatory, antioxidant, and antibacterial properties. The aim of this study was to prepare a set of Licarin A derivatives and investigate the impact of specific structural changes on its antimycobacterial ability, and its effect on the biofilm formation of RGM species. Initially, the phenolic sub-unit and alkenyl side chain of Licarin A were modified to create derivatives with a higher partition coefficient; as the activity of a compound against mycobacteria seems to be strongly influenced by its hydrophobicity. Further, polar groups were inserted into the side chain to change the hydrophilic-lipophilic profile of the molecules. Results showed variability in the susceptibility profile of mycobacteria against the Licarin A derivatives under analysis. A number of the derivatives showed significant inhibitory activity of planktonic growth of the three strains of mycobacteria used, with even lower MIC values than those observed with reference drugs and Licarin A itself. Cytotoxicity assays showed they also have low toxicity, confirming that structural modifications to the Licarin A have made improvements to its antimycobacterial properties.
Assuntos
Biofilmes/efeitos dos fármacos , Lignanas/química , Lignanas/farmacologia , Mycobacterium/efeitos dos fármacos , Micobactérias não Tuberculosas/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Claritromicina/farmacologia , Testes de Sensibilidade Microbiana , Myristica/química , Micobactérias não Tuberculosas/fisiologia , Sulfametoxazol/farmacologiaRESUMO
BACKGROUND: Tuberculosis is a disease with high incidence and high mortality rate, especially in Brazil. Although there are several medications available for treatment, in cases of resistance, there is a need to use more than one medication. OBJECTIVE: Therefore, cases of toxicity increase and reports of resistance have been worrying the population. In addition, some medications have a short period of effectiveness. To achieve the goal, ligand-based and structure-based approaches were used. METHODS: Thus, in an attempt to discover potent inhibitors against Mycobacterium tuberculosis enzymes, we sought to identify natural products with high therapeutic potential for the treatment of Tuberculosis through QSAR, Molecular Modeling and ADMET studies. RESULTS: The results showed that the models generated from two sets of molecules with known activity against M. tuberculosis enzymes InhA and PS were able to select 11 and 8 compounds, respectively, between Lignans and Neolignans with 50 to 60% activity probability. In addition, molecular docking contributed to confirm the mechanism of action of compounds and increase the accuracy of methodologies. All molecules showed higher binding energy values for the drug Isoniazid. We conclude that compounds 33, 34, 110, 114 and 133 are promising for InhA target and compounds 07, 08, 19, 21, 42, 48, 75 and 141 for target PS. In addition, most molecules did not show any toxicity according to the evaluated parameters. CONCLUSION: Therefore, Lignans and Neolignans may be an alternative for the treatment of Tuberculosis.
Assuntos
Antituberculosos/farmacologia , Lignanas/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Tuberculose/tratamento farmacológico , Antituberculosos/química , Antituberculosos/isolamento & purificação , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Humanos , Lauraceae/química , Lignanas/química , Lignanas/isolamento & purificação , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Mycobacterium tuberculosis/metabolismo , Tuberculose/metabolismoRESUMO
Nectandra leucantha (Lauraceae) is a tree indigenous to the tropical Atlantic forests of Brazil, one of the most biodiverse flora hotspots worldwide. This plant species contains high concentrations of neolignan and dehydrodieugenol derivatives that express significant in-vitro activities against various parasite strains. These activities are however responsible for severe tropical human infections, such as Leishmaniasis (Leishmania spp.) and Chagas disease (Trypanosoma cruzi), which have been classified by the World Health Organization (WHO) as Neglected Tropical Diseases (NTDs). In order to optimize the isolation process for these target metabolites, n-hexane extract of the leaves was separated by means of semi-preparative high performance countercurrent chromatography (HPCCC) and scale-up spiral-coil countercurrent chromatography (sp-CCC) systems. Several biphasic solvent mixtures were evaluated for their partitioning effects on neolignans, resulting in the selection of an optimized system n-hexane - ethylacetate - methanol - water (7:3:7:3, v/v/v/v). The chromatographic experiments on the HPCCC and sp-CCC were run in the head-to-tail mode with 500â¯mg and 16â¯g injections, respectively. For specific and multiple metabolite detection, the recovered CCC-fractions were off-line injected, in the sequence of recovery, to an electrospray mass-spectrometry (ESI-MS/MS) device. A projection of the single ion traces of the target compounds, in the positive ionization mode at a scan range of m/z 100-1500, located chromatographic areas where the co-elution effects occurred and pure target metabolites were present. Five major target neolignans were specifically detected, which enabled the accurate pooling of CCC-fractions for an optimum recovery of the metabolites. The direct comparison of the performance characteristics of the two CCC-devices, with very different mechanical designs was achieved by the conversion of the time axis into a partition ratio (KD) separation scale. As a result, the compound specific KD-elution values of the target neolignan were determined in high precision, while the comparison of the calculated separation factor (α) and resolution factor (RS) values revealed a superior separation performance for the HPCCC system. Also, the reproducibility of detected metabolites in the two CCC experiments was confirmed by small variations (ΔKD⯱0.1). Neolignan target compounds with anti-parasite activities were successfully isolated in the 100â¯mg to 4â¯g range in a single lab-scale countercurrent chromatographic process step.
Assuntos
Distribuição Contracorrente/métodos , Lauraceae/química , Lignanas/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas em Tandem/métodos , Brasil , Cromatografia Líquida de Alta Pressão/métodos , Eugenol/análogos & derivados , Eugenol/análise , Eugenol/isolamento & purificação , Lignanas/análise , Extratos Vegetais/análise , Folhas de Planta/químicaRESUMO
Isoxazole analogues derived from the neolignans veraguensin, grandisin, and machilin G were previously synthesized with different substitution patterns through the bioisosterism strategy. These compounds were tested on intracellular amastigotes of Leishmania (Leishmania) amazonensis; the derivatives proved to be active against intracellular amastigotes, with IC50 values ranging from 0.4 to 25 µM. The most active analogues were 4', 14', 15', and 18', with IC50 values of 0.9, 0.4, 0.7, and 1.4 µM, respectively, showing high selectivity indexes (SI = 277.0; 625.0; 178.5 and 357.1). Overall, the isoxazole analogues did not induce nitric oxide (NO) production by infected cells; there was no evidence that NO influences the antileishmanial mechanism of action, except for compound 4'. Trimethoxy groups as substituents seemed to be critical for antileishmanial activity. The SAR study demonstrated that the isoxazole compounds were more active than 1,2,3-triazole compounds with the same substitution pattterns, demonstrating the importance of the bioisosterism strategy in drug design.
Assuntos
Antiprotozoários/farmacologia , Furanos/química , Isoxazóis/química , Leishmania/efeitos dos fármacos , Lignanas/química , Triazóis/química , Animais , Antiprotozoários/química , Desenho de Fármacos , Feminino , Concentração Inibidora 50 , Isoxazóis/farmacologia , Leishmania/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Relação Estrutura-AtividadeRESUMO
The MeOH extract from leaves of Saururus cernuus L. (Saururaceae) displayed in vitro activity against trypomastigote forms of T. cruzi (100% of parasite death at 200⯵g/mL), suggesting the presence of bioactive compounds. Thus, the bioactivity-guided fractionation was carried out, leading to the isolation of three related neolignan derivatives, identified as threo-austrobailignan-5 (1), threo-austrobailignan-6 (2), and threo-dihydroguaiaretic acid (3). Anti-T. cruzi activity of compounds 1-3 was performed against cell-derived trypomastigotes and intracellular amastigotes. Additionally, the mammalian cytotoxicity was investigated using NCTC cells. Compound 2 was the most effective against extracellular trypomastigotes with IC50 of 3.7⯵M, while compound 3 showed activity in both clinically relevant forms of the parasite, trypomastigotes and amastigotes, with IC50 values of 7.0 and 16.2⯵M, respectively. However, the structurally related compound 1 was inactive. Based on these results, compounds 2 and 3 were selected to evaluate the mechanism of cellular death. Compound 2 induced alteration in the plasma membrane permeability and consequently in the ROS levels after 120â¯min of incubation. By using flow cytometry and fluorescence microscopy, compound 3 showed alterations in the mitochondrial membrane potential (ΔΨm) of trypomastigotes. Considering the promising chemical and biological properties of neolignans 2 and 3, these compounds could be used as starting points to develop new lead compounds for Chagas disease.
Assuntos
Lignanas/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Saururaceae/química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Brasil , Células Cultivadas , Guaiacol/análogos & derivados , Lignanas/isolamento & purificação , Macrófagos Peritoneais/parasitologia , Camundongos Endogâmicos BALB C , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Espécies Reativas de Oxigênio/metabolismo , Tripanossomicidas/isolamento & purificaçãoRESUMO
Chagas disease is a neglected protozoan disease that affects more than eight million people in developing countries. Due to the limited number and toxicity profiles of therapies in current use, new drugs are urgently needed. In previous studies, we reported the isolation of two related antitrypanosomal neolignans from Nectandra leucantha (Lauraceae). In this work, a semi-synthetic library of twenty-three neolignan derivatives was prepared to explore synthetically accessible structure activity relationships (SAR) against Trypanosoma cruzi. Five compounds demonstrated activity against trypomastigotes (IC50 values from 8 to 64⯵M) and eight showed activity against intracellular amastigotes (IC50 values from 7 to 16⯵M). Eighteen derivatives demonstrated no mammalian cytotoxicity up to 200⯵M. The phenolic acetate derivative of natural dehydrodieugenol B was effective against both parasite forms and eliminated 100% of amastigotes inside macrophages. This compound caused rapid and intense depolarization of the mitochondrial membrane potential, with decreased levels of intracellular reactive oxygen species being observed. Fluorescence assays demonstrated that this derivative affected neither the permeability nor the electric potential of the parasitic plasma membrane, an effect also corroborated by scanning electron microscopy studies. Structure-activity relationship studies (SARs) demonstrated that the presence of at least one allyl side chain on the biaryl ether core was important for antitrypanosomal activity, and that the free phenol is not essential. This set of neolignan derivatives represents a promising starting point for future Chagas disease drug discovery studies.
Assuntos
Anisóis/farmacologia , Lignanas/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Anisóis/síntese química , Anisóis/química , Anisóis/toxicidade , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Humanos , Lignanas/síntese química , Lignanas/química , Lignanas/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Testes de Sensibilidade Parasitária , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Tripanossomicidas/síntese química , Tripanossomicidas/química , Tripanossomicidas/toxicidade , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismoRESUMO
Using bioisosterism as a medicinal chemistry tool, 16 3,5-diaryl-isoxazole analogues of the tetrahydrofuran neolignans veraguensin, grandisin and machilin G were synthesized via 1,3-dipolar cycloaddition reactions, with yields from 43% to 90%. Antitrypanosomatid activities were evaluated against Trypanosoma cruzi, Leishmania (L.) amazonensis and Leishmania (V.) braziliensis. All compounds were selective for the Leishmania genus and inactive against T. cruzi. Isoxazole analogues showed a standard activity on both promastigotes of L. amazonensis and L. braziliensis. The most active compounds were 15, 16 and 19 with IC50 values of 2.0, 3.3 and 9.5 µM against L. amazonensis and IC50 values of 1.2, 2.1 and 6.4 µM on L. braziliensis, respectively. All compounds were noncytotoxic, showing lower cytotoxicity (>250 µM) than pentamidine (78.9 µM). Regarding the structure-activity relationship (SAR), the methylenedioxy group was essential to antileishmanial activity against promastigotes. Replacement of the tetrahydrofuran nucleus by an isoxazole core improved the antileishmanial activity.
Assuntos
Antiprotozoários/química , Desenho de Fármacos , Furanos/química , Isoxazóis/química , Lignanas/química , Animais , Antiprotozoários/síntese química , Antiprotozoários/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Concentração Inibidora 50 , Isoxazóis/síntese química , Isoxazóis/farmacologia , Leishmania/efeitos dos fármacos , Camundongos , Células NIH 3T3 , Relação Estrutura-Atividade , Trypanosoma cruzi/efeitos dos fármacosRESUMO
In this work was evaluated the cytotoxic activity of dehydrodieugenol B (1) and methyldehydrodieugenol B (2) isolated from Nectandra leucantha (Lauraceae) through cytokinesis-block micronucleus (CBMN) and Comet assay. Compounds 1 and 2 displayed in vitro toxicity against human melanoma cells (SKMEL-147) with IC50 values of 4.4 and 43.6⯵g/mL, respectively. The interaction of these compounds with resistant human melanoma cell line SKMEL-29 was also investigated. Obtained results showed a concentration-response relationship for DNA damage (DI and D%) in SKMEL-29 cells for compounds 1 and 2 causing an increase in DNA damage on their lower concentrations. Concerning the cytokinesis-block micronucleus cytome (CBMNCyt) assay, all treatments demonstrated an increase in cytostatic and cytotoxic indexes. In micronucleus quantification, compound 1 displayed higher index in comparison to control. Regarding necrotic and apoptotic cells, treatments with SKMEL-29 cells demonstrated 100% of cell death induced by compounds 1 and 2 at 25 and 88⯵g/mL, respectively. Additionally, it was observed that apoptosis is prevalent in SKMEL-147 cells treated with compound 1, while necrotic cells were observed in SKMEL-29 cells treated with both compounds. In conclusion, compounds 1 and 2 are suggested as promising cytotoxic agents against human melanoma resistant cells, emphasizing the potential use of these neolignans for the treatment of melanoma.
Assuntos
Citotoxinas/farmacologia , Lauraceae , Lignanas/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA , Humanos , Melanoma/tratamento farmacológico , Testes para Micronúcleos , Caules de PlantaRESUMO
We have investigated gas-phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate-mass electrospray ionization tandem and multiple-stage (MSn ) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ([M + H-MeOH]+ ), C ([B-MeOH]+ ), D ([C-CO]+ ), and E ([D-CO]+ ) upon collision-induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features. In the case of compounds displaying an acetoxy group at C-4, product ion C produces diagnostic ions K ([C-C2 H2 O]+ ), L ([K-CO]+ ), and P ([L-CO]+ ). Formation of product ions H ([D-H2 O]+ ) and M ([H-CO]+ ) is associated with the hydroxyl group at C-3 and C-3', whereas product ions N ([D-MeOH]+ ) and O ([N-MeOH]+ ) indicate a methoxyl group at the same positions. Finally, product ions F ([A-C2 H2 O]+ ), Q ([A-C3 H6 O2 ]+ ), I ([A-C6 H6 O]+ ), and J ([I-MeOH]+ ) for DBNs and product ion G ([B-C2 H2 O]+ ) for BNs diagnose a saturated bond between C-7' and C-8'. We used these structure-fragmentation relationships in combination with deuterium exchange experiments, MSn data, and Computational Chemistry to elucidate the gas-phase fragmentation pathways of these compounds. These results could help to elucidate DBN and BN metabolites in in vivo and in vitro studies on the basis of electrospray ionization ESI-CID-MS/MS data only.
RESUMO
BACKGROUND: The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (1-6) of bioactive extract from Nectandra leucantha (Lauraceae) twigs. METHODS: Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 1-6. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 1-6 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum. RESULTS: Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 1-6. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 µM, respectively), while compounds 1 and 3 were inactive. As neolignans 2-4 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 = 16.9 µM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity, suggesting that the formation of dimeric compounds by oxidative coupling is crucial for antiparasitic activity of dimeric compounds 2, 4 and 6. CONCLUSION: This study highlights compound 6 against L. (L.) infantum amastigotes as a scaffold for future design of new compounds for drug treatment of visceral leishmaniasis.
RESUMO
Background:The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (16) of bioactive extract from Nectandra leucantha (Lauraceae) twigs.Methods:Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 16. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 16 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum.Results:Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 16. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 μM, respectively), while compounds 1 and 3 were inactive. As neolignans 24 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 =16.9 μM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity...(AU)
Assuntos
Lauraceae , Lignanas/análise , Leishmaniose/tratamento farmacológico , Leishmania infantum , Técnicas In VitroRESUMO
We have evaluated the antischistosomal activity of synthetic dihydrobenzofuran neolignans (DBNs) derived from (±)-trans-dehydrodicoumaric acid dimethyl ester (1) and (±)-trans-dehydrodiferulic acid dimethyl ester (2) against adult Schistosoma mansoni worms in vitro. Compound 4 ((±)-trans-4-O-acetyldehydrodiferulic acid dimethyl ester) displayed the most promising activity; at 200 µm, it kills 100 ± 0% of worms after 24 h, which resembles the result achieved with praziquantel (positive control) at 1.56 µm. The hydrogenation of the double bond between C7' and C8', the introduction of an additional methyl group at C3', and a double bond between C7 and C8 decreased the schistosomicidal activity of DBNs. On the other hand, the presence of the acetoxy group at C4 played an interesting role in this activity. These results demonstrated the interesting schistosomicidal potential of DBNs, which could be further exploited.
Assuntos
Lignanas/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Esquistossomicidas/farmacologia , Animais , Relação Dose-Resposta a Droga , Lignanas/síntese química , Lignanas/química , Estrutura Molecular , Esquistossomicidas/síntese química , Esquistossomicidas/químicaRESUMO
The therapeutic arsenal for the treatment of Leishmaniasis is limited and includes toxic compounds (antimonials, amphotericin B, pentamidine and miltefosine). Given these aspects, the search for new compounds based on floristic biodiversity is crucial. In the present work, we report the isolation, characterization and antileishmanial activity of six related neolignans (16) of bioactive extract from Nectandra leucantha (Lauraceae) twigs. Methods: Dried and powdered twigs of N. leucantha were exhaustively extracted using n-hexane. The crude extract was dereplicated by HPLC/HRESIMS and subjected to column chromatography to yield pure compounds 16. Their chemical structures were identified via NMR and comparison of obtained data with those previously published in the literature. Biological assays of compounds 16 and their respective monomers (eugenol and methyleugenol) were performed using promastigote and amastigote forms of Leishmania (L.) infantum. Results: Dereplication procedures followed by chemical characterization of isolated compounds by NMR enabled the identification of related neolignans 16. Neolignans 2, 4 and 6 showed potential against amastigote forms of L. (L.) infantum (EC50 values of 57.9, 67.7 and 13.7 µM, respectively), while compounds 1 and 3 were inactive. As neolignans 24 are chemically related, it may be suggested that the presence of the methoxyl group at C4 constitutes an important structural aspect to increase antileishmanial potential against amastigote forms. Compound 6, which consists of a methylated derivative of compound 5 (inactive) showed antileishmanial activity similar to that of the standard drug miltefosine (EC50 =16.9 µM) but with reduced toxicity (SI = 14.6 and 7.2, respectively). Finally, two related monomers, eugenol and methyleugenol, were also tested and did not display activity, suggesting that the formation of dimeric compounds by oxidative coupling is crucial for antiparasitic activity of dimeric compounds 2, 4 and 6. Conclusion: This study highlights compound 6 against L. (L.) infantum amastigotes as a scaffold for future design of new compounds for drug treatment of visceral leishmaniasis.(AU)