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1.
Planta Med ; 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32645738

RESUMO

Fungi are a rich source of bioactive compounds. Fungal cocultivation is a method of potentiating chemical interactions and, consequently, increasing bioactive molecule production. In this study, we evaluated the bactericidal, antiprotozoal, and cathepsin V inhibition activities of extracts from axenic cultures of 6 fungi (Fusarium guttiforme, Pestalotiopsis diospyri, Phoma caricae-papayae, Colletotrichum horii, Phytophthora palmivora, and C. gloeosporioides) that infest tropical fruits and 57 extracts obtained by their cocultivation. Our results reveal that fungal cocultivation enhances the biological activity of the samples, since all extracts that were active on Gram-positive bacteria, Gram-negative bacteria, Trypanosoma cruzi, and Leishmania infantum were obtained from cocultivation. Bacterial growth is either totally or partially inhibited by 46% of the extracts. Two extracts containing mainly fusaric and 9,10-dehydrofusaric acids were particularly active. The presence of the fungus F. guttiforme in co-cultures that give rise to extracts with the highest activities against L. infantum. An axenic culture gave rise to the most active extract for the inhibition of cathepsin V; however, other coculture extracts also exhibited activity toward this biological target. Therefore, the results of the biological activities indicate that fungal cocultivation increased the biological potential of samples, likely due to the hostile and competitive environment that pushes microorganisms to produce substances important for defense and allows access to metabolic routes then silenced in milder cultivation conditions.

2.
Braz J Microbiol ; 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32189177

RESUMO

Papain-like cysteine proteases (PLCPs) in plants are essential to prevent phytopathogen invasion. In order to search for cysteine protease inhibitors and to investigate compounds that could be associated to pineapple Fusarium disease, a chemistry investigation was performed on Fusarium proliferatum isolated from Ananas comosus (pineapple) and cultivated in Czapek medium. From F. proliferatum extracts, nine secondary metabolites were isolated and characterized by nuclear magnetic resonance spectroscopy and mass spectrometry experiments: beauvericin (1), fusaric acid (2), N-ethyl-3-phenylacetamide (3), N-acetyltryptamine (4), cyclo(L-Val-L-Pro) cyclodipeptide (5), cyclo(L-Leu-L-Pro) cyclodipeptide (6), cyclo(L-Leu-L-Pro) diketopiperazine (7), 2,4-dihydroxypyrimidine (8), and 1H-indole-3-carbaldehyde (9). Compounds 1, 3, and 6 showed significant inhibition of papain, with IC50 values of 25.3 ± 1.9, 39.4 ± 2.5, and 7.4 ± 0.5 µM, respectively. Compound 1 also showed significant inhibition against human cathepsins V and B with IC50 of 46.0 ± 3.0 and 6.8 ± 0.7 µM, respectively. The inhibition of papain by mycotoxins (fusaric acid and beauvericin) may indicate a mechanism of Fusarium in the roles of infection process.

3.
J Pharm Biomed Anal ; 179: 112960, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31791839

RESUMO

New antifungals are increasingly needed due to the emergence of resistant fungal strains. Traditional antifungal assays are laborious and require significant amounts of samples. The present work presents a new proposal to evaluate antifungal activity and antagonism among fungal species, based on experiments of fungal culture and co-culture, 1H NMR profile of fungal culture extracts and chemometrics. In order to develop the work, six axenic cultures of fungi that infested fruits (Fusarium guttiforme, Pestalotiopsis diospyri, Phoma caricae-papayae, Colletotrichum horii, Phytophthora palmivora, and C. gloeosporioides), and co-cultures of all possible combination among them were performed (totalizing 63 experiments). All fungal extracts were evaluated by 1H NMR followed by Principal Component Analyses (PCA) in order to determine spectral dissimilarity among the extracts. Results showed that 1H NMR data evaluated by PCA were capable to predict both antagonism and antifungal activity. Traditional antifungal in vitro assays of active and inactive extracts were also performed in order to prove the prediction made by PCA. The obtained data showed that the approach is an outstanding tool to simultaneously obtain and evaluate bioactive compounds because: it was able to predict the activity of five different extracts in a collection of sixty-three, which would be much more difficult and time consuming if applied randomly; most important antifungal extracts are indicated by PCA; hundreds of traditional in vitro assays are avoid; and, the method is very time and money saving.

4.
Chem Biol Interact ; 316: 108920, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31857088

RESUMO

Cedrelone is a limonoid isolated from the plant Trichilia catigua (Meliaceae). Previous studies have demonstrated that cedrelone (1) has several damaging effects on triple negative breast tumor (TNBC) cell line MDA-MB-231. In this work we investigated two new derivatives of cedrelone, the acetate (1a) and the mesylate (1b), to examine whether their effects are improved in comparison to the lead molecule. Cedrelone acetate (1a) was the most cytotoxic compound on TNBC cells and was chosen for additional analyses in traditional two-dimensional (2D) monolayer cultures and three-dimensional (3D) assays. In 2D, 1a induced cell cycle arrest, apoptosis and inhibited essential steps of the metastasis process of the MDA-MB-231 cells, in vitro. Moreover, 1a was able to revert the malignant phenotype of the T4-2 cells in 3D. These effects were concomitant with the downregulation of EGFR, ß1-integrin and phospho-Akt, which could have resulted in a decrease of NFκB levels and MMP9 activity. These results suggest that 1a could be used as an important model for the design of a new drug to be applied in cancer treatment and be further studied in vivo for its antitumor and antimetastatic effects.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Limoninas/química , Acetilação , Antineoplásicos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Técnicas de Cultura de Células , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Humanos , Integrina beta1/genética , Integrina beta1/metabolismo , Limoninas/farmacologia , Meliaceae/química , Meliaceae/metabolismo , Fenótipo
5.
Phytochemistry ; 163: 38-45, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31003042

RESUMO

Two highly oxygenated nortriterpenes, picraviane A and B, were isolated from the ethanolic extract of Picramnia glazioviana Engl. The structures were determined by analysis of HRMS and 2D NMR spectroscopic data. Single-crystal X-ray diffraction data was also obtained for picraviane B. The absolute configuration of both compounds were assigned by comparison of experimental and calculated vibrational and electronic circular dichroism spectroscopy, respectively. Picraviane A showed a moderate cytotoxic activity against the triple negative MDA-MB-231 breast cancer cell line. These compounds represent an undescribed class of natural products with limonoid-like skeletons containing a heptanolide as the E-ring.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Produtos Biológicos/farmacologia , Simaroubaceae/química , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Conformação Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Triterpenos/química , Triterpenos/isolamento & purificação
6.
Chem Biol Drug Des ; 93(2): 139-146, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30216691

RESUMO

This study describes the activity of five natural hydroxycinnamic acids and derived compound: caffeic (1), rosmarinic (2), chlorogenic (3), and cryptochlorogenic (4), acids and isoverbascoside (5). All compounds inhibited Leishmania amazonensis arginase with IC50 -in range of 1.5-11 µM. Compounds 2 and 5 also showed activity against promastigotes of L. amazonensis with IC50  = 61 (28-133) µM and IC50  = 14 (9-24) µM, respectively. Further computational studies applying molecular docking simulations were performed on the competitive inhibitors to gain insight into the molecular basis for arginase inhibition and could be exploited to the development of new antileishmanials drug targeting parasite arginase.


Assuntos
Antiprotozoários/química , Arginase/metabolismo , Cinamatos/química , Leishmania/enzimologia , Proteínas de Protozoários/metabolismo , Antiprotozoários/metabolismo , Antiprotozoários/farmacologia , Arginase/antagonistas & inibidores , Sítios de Ligação , Cinamatos/metabolismo , Concentração Inibidora 50 , Cinética , Leishmania/efeitos dos fármacos , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Proteínas de Protozoários/antagonistas & inibidores
7.
Molecules ; 23(11)2018 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-30413007

RESUMO

A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests.


Assuntos
Eugenol/análogos & derivados , Pimenta/química , Cromatografia Líquida de Alta Pressão , Eugenol/isolamento & purificação , Óleos Voláteis/química , Folhas de Planta/química , Óleos Vegetais/química
9.
J Pharm Biomed Anal ; 151: 252-259, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29367161

RESUMO

The treatment of diseases using enzymes as targets has called for the development of new and reliable methods for screening. The protease cathepsin D is one such target involved in several diseases such as tumors, degenerative processes, and vital processes of parasites causing schistosomiasis. Herein, we describe the preparation of a fused silica capillary, cathepsin D (CatD)-immobilized enzyme reactor (IMER) using in a multidimensional High Performance Liquid Chromatography-based method (2D-HPLC) and zonal affinity chromatography as an alternative in the search for new ligands. The activity and kinetic parameters of CatD-IMER were evaluated by monitoring the product MOCAc-Gly-Lys-Pro-Ile-Leu-Phe (P-MOCAc) (KM = 81.9 ±â€¯7.49 µmol/L) generated by cleavage of the fluorogenic substrate MOCAc-Gly-Lys-Pro-Ile-Leu-Phe-Phe-Arg-Leu-Lys(DNP)-d-Arg-NH2 (S-MOCAc). Stability studies have indicated that CatD-IMER retained 20% of activity after 5 months, a relevant result, because proteases are susceptible to autoproteolysis in solution assays with free enzyme. In the search for inhibitors, 12 crude natural product extracts were analyzed using CatD-IMER as the target, resulting in the isolation of different classes of natural products. In addition, 26 compounds obtained from different species of plants were also screened, demonstrating the efficiency and reproducibility of the herein reported assay even in the case of complex matrices such as plant crude extracts.


Assuntos
Catepsina D/antagonistas & inibidores , Inibidores Enzimáticos/análise , Enzimas Imobilizadas/antagonistas & inibidores , Extratos Vegetais/análise , Catepsina D/química , Catepsina D/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Avaliação Pré-Clínica de Medicamentos/instrumentação , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Ligantes , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Reprodutibilidade dos Testes , Dióxido de Silício/química , Especificidade por Substrato
10.
Oncotarget ; 8(42): 72260-72271, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29069785

RESUMO

There is increasing interest in the use of non-toxic natural products for the treatment of various pathologies, including cancer. In particular, biologically active constituents of the ginger oleoresin (Zingiber officinale Roscoe) have been shown to mediate anti-tumour activity and to contribute to the anti-inflammatory, antioxidant, antimicrobial, and antiemetic properties of ginger. Here we report on the inhibitory properties of [10]-gingerol against metastatic triple negative breast cancer (TNBC) in vitro and in vivo. We show that [10]-gingerol concentration-dependently induces apoptotic death in mouse and human TNBC cell lines in vitro. In addition, [10]-gingerol is well tolerated in vivo, induces a marked increase in caspase-3 activation and inhibits orthotopic tumour growth in a syngeneic mouse model of spontaneous breast cancer metastasis. Importantly, using both spontaneous and experimental metastasis assays, we show for the first time that [10]-gingerol significantly inhibits metastasis to multiple organs including lung, bone and brain. Remarkably, inhibition of brain metastasis was observed even when treatment was initiated after surgical removal of the primary tumour. Taken together, these results indicate that [10]-gingerol may be a safe and useful complementary therapy for the treatment of metastatic breast cancer and warrant further investigation of its efficacy, either alone or in combination with standard systemic therapies, in pre-clinical models of metastatic breast cancer and in patients.

11.
Molecules ; 22(6)2017 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-28608830

RESUMO

Diketopiperazines can be generated by non-enzymatic cyclization of linear dipeptides at extreme temperature or pH, and the complex medium used to culture bacteria and fungi including phytone peptone and trypticase peptone, can also produce cyclic peptides by heat sterilization. As a result, it is not always clear if many diketopiperazines reported in the literature are artifacts formed by the different complex media used in microorganism growth. An ideal method for analysis of these compounds should identify whether they are either synthesized de novo from the products of primary metabolism and deliver true diketopiperazines. A simple defined medium (X. fastidiosa medium or XFM) containing a single carbon source and no preformed amino acids has emerged as a method with a particularly high potential for the grown of X. fastidiosa and to produce genuine natural products. In this work, we identified a range of diketopiperazines from X. fastidiosa 9a5c growth in XFM, using Ultra-Fast Liquid Chromatography coupled with mass spectrometry. Diketopiperazines are reported for the first time from X. fastidiosa, which is responsible for citrus variegated chlorosis. We also report here fatty acids from X. fastidiosa, which were not biologically active as diffusible signals, and the role of diketopiperazines in signal transduction still remains unknown.


Assuntos
Dicetopiperazinas/farmacologia , Peptonas/química , Xylella/efeitos dos fármacos , Carbono/química , Caseínas/química , Cromatografia Líquida , Dicetopiperazinas/síntese química , Dicetopiperazinas/química , Peptonas/síntese química , Peptonas/farmacologia , Hidrolisados de Proteína/química , Espectrometria de Massas por Ionização por Electrospray , Xylella/crescimento & desenvolvimento
12.
Antonie Van Leeuwenhoek ; 110(4): 593-605, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28040855

RESUMO

Leaf-cutter ants cultivate and feed on the mutualistic fungus, Leucoagaricus gongylophorus, which is threatened by parasitic fungi of the genus Escovopsis. The mechanism of Escovopsis parasitism is poorly understood. Here, we assessed the nature of the antagonism of different Escovopsis species against its host. We also evaluated the potential antagonism of Escovopsioides, a recently described fungal genus from the attine ant environment whose role in the colonies of these insects is unknown. We performed dual-culture assays to assess the interactions between L. gongylophorus and both fungi. We also evaluated the antifungal activity of compounds secreted by the latter on L. gongylophorus growth using crude extracts of Escovopsis spp. and Escovopsioides nivea obtained either in (1) absence or (2) presence of the mutualistic fungus. The physical interaction between these fungi and the mutualistic fungus was examined under scanning electron microscopy (SEM). Escovopsis spp. and E. nivea negatively affected the growth of L. gongylophorus, which was also significantly inhibited by both types of crude extract. These results indicate that Escovopsis spp. and E. nivea produce antifungal metabolites against the mutualistic fungus. SEM showed that Escovopsis spp. and E. nivea maintained physical contact with the mutualistic fungus, though no specialised structures related to mycoparasitism were observed. These results showed that Escovopsis is a destructive mycoparasite that needs physical contact for the death of the mutualistic fungus to occur. Also, our findings suggest that E. nivea is an antagonist of the ant fungal cultivar.


Assuntos
Agaricales/metabolismo , Antibiose/fisiologia , Antifúngicos/metabolismo , Formigas/microbiologia , Extratos Celulares/farmacologia , Hypocreales/patogenicidade , Animais , Técnicas de Cocultura , Microscopia Eletrônica de Varredura , Simbiose/fisiologia
13.
ACS Omega ; 2(12): 8794-8795, 2017 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31457408
14.
Biochem Pharmacol ; 127: 28-33, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28017773

RESUMO

Verbascoside is the main component of the traditional medicinal plants that were used against protozoa parasites that cause malaria and leishmaniasis. Previously, we have described verbascoside inhibition of Leishmania amazonensis arginase as well as its antileishmanial action against extracellular promastigotes. In this study, we have assessed arginase parasite inhibition in intracellular amastigotes. In addition, we verified whether verbascoside can influence the host defense against the parasite by measuring gene expression of cytokines IL-1b, IL-10, IL-18, TNF-α and murine macrophage arginase as well as nitric oxide synthase enzymes. Our results show that verbascoside acts on intracellular amastigotes of L. amazonensis (EC50=32µM) by selectively inhibiting the parasite arginase. Verbascoside did not affect the expression of cytokines or enzymes by murine macrophages. However, verbascoside was active against L. (L.) amazonensis amastigotes that were resistant to treatment with LPS and IFN-γ. Verbascoside action on L. amazonensis can be associated with reduction of the protective oxidative mechanism of the parasite leading to impaired trypanothione synthesis that is induced by the parasite arginase inhibition.


Assuntos
Antiprotozoários/farmacologia , Arginase/antagonistas & inibidores , Glucosídeos/farmacologia , Interferon gama/farmacologia , Leishmania/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Fenóis/farmacologia , Proteínas de Protozoários/antagonistas & inibidores , Animais , Linhagem Celular , Citocinas/metabolismo , Resistência a Medicamentos , Leishmania/enzimologia , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Camundongos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo
15.
J Ethnopharmacol ; 192: 108-113, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27432217

RESUMO

ETHNOPHARMACOLOGY RELEVANCE: Stachytarpheta cayennensis is a plant that is traditionally used to treat tegumentary leishmaniasis and as an anti-inflammatory agent. AIM OF THE STUDY: This study aimed to evaluate the action of S. cayennensis extracts on the Leishmania (Leishmania) amazonensis arginase enzyme. MATERIALS AND METHODS: S. cayennensis was collected from the Brazilian Amazon region. Aqueous extracts were fractionated with n-butanol. The leishmanicidal effects of the n-butanolic fraction (BUF) were evaluated in L. (L.) amazonensis promastigotes and amastigotes. BUF was tested against recombinant arginase from both L. (L.) amazonensis and macrophage arginase. Promastigote cultures and infected macrophage cultures were supplemented with L-ornithine to verify arginase inhibition. NMR analysis was used to identify the major components of BUF. RESULTS: BUF showed an EC50 of 51 and 32µg/mL against promastigotes and amastigotes of L. (L.) amazonensis, respectively. BUF contains a mixture of verbascoside and isoverbascoside (7:3 ratio) and is a potent L. (L.) amazonensis arginase inhibitor (IC50=1.2µg/mL), while macrophage arginase was weakly inhibited (IC50>1000µg/mL). The inhibition of arginase by BUF in promastigotes and amastigotes could be demonstrated by culture media supplementation with L-ornithine, a product of the hydrolysis of L-arginine by arginase. CONCLUSIONS: Leishmanicidal effects of the S. cayennensis BUF fraction on L. (L.) amazonensis are associated with selective parasite arginase inhibition.


Assuntos
Arginase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Leishmania/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proteínas de Protozoários/antagonistas & inibidores , Tripanossomicidas/farmacologia , Verbenaceae/química , 1-Butanol/química , Animais , Arginase/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/isolamento & purificação , Leishmania/enzimologia , Leishmania/crescimento & desenvolvimento , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Macrófagos/parasitologia , Camundongos , Ornitina/farmacologia , Testes de Sensibilidade Parasitária , Fitoterapia , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Proteínas de Protozoários/metabolismo , Células RAW 264.7 , Solventes/química , Tripanossomicidas/isolamento & purificação
16.
Molecules ; 21(6)2016 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-27338332

RESUMO

The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-ß-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-ß-ocimene, and ß-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.


Assuntos
Citrus/efeitos dos fármacos , Hemípteros/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Animais , Brasil , Citrus/genética , Citrus/parasitologia , Genótipo , Hemípteros/patogenicidade , Repelentes de Insetos/química , Repelentes de Insetos/farmacologia , Óleos Voláteis/química , Fitol/química , Fitol/farmacologia , Óleos Vegetais/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia
17.
Chem Biodivers ; 13(3): 284-292, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26916413

RESUMO

A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.


Assuntos
Malvaceae/química , Ácido Oleanólico/análogos & derivados , Fotossíntese/efeitos dos fármacos , Complexo de Proteínas do Centro de Reação Fotossintética/antagonistas & inibidores , Técnicas In Vitro , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo
18.
Rev. bras. farmacogn ; 25(5): 451-454, Sept.-Oct. 2015. tab, graf
Artigo em Inglês | LILACS-Express | ID: lil-765071

RESUMO

ABSTRACTThe antimicrobial activity of the myrsinoic acid A isolated from Myrsine coriacea (Sw.) R.Br. ex Roem. & Schult., Primulaceae, and a two semi-synthetics derivatives was tested against Bacillus subtilis, Escherichia coli, Salmonella enterica subsp. enterica serovar typhi, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Micrococcus luteus, Candida albicans, Candida krusei and Candida tropicalis. The microdilution method was used for the determination of the minimum inhibitory concentration during evaluation of the antimicrobial activity. The myrsinoic acid A showed no activity against the selected microorganisms but the hydrogenated and acetylated derivatives were active against B. subtilis, E. coli, S. aureus and P. aeruginosa.

19.
Phytochemistry ; 115: 161-70, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25749617

RESUMO

A high performance liquid chromatography-ultraviolet (HPLC-UV) method was developed for quantifying hesperidin and rutin levels in leaves and stems of Citrus limonia, with a good linearity over a range of 1.0-80.0 and 1.0-50.0 µg mL(-1) respectively, with r(2)>0.999 for all curves. The limits of detection (LOD) for both flavonoids were 0.6 and 0.5 µg mL(-1), respectively, with quantification (LOQ) being 2.0 and 1.0 µg mL(-1), respectively. The quantification method was applied to Citrus sinensis grafted onto C. limonia with and without CVC (citrus variegated chlorosis) symptoms after Xylella fastidiosa infection. The total content of rutin was low and practically constant in all analyses in comparison with hesperidin, which showed a significant increase in its amount in symptomatic leaves. Scanning electron microscopy studies on leaves with CVC symptoms showed vessel occlusion by biofilm, and a crystallized material was noted. Considering the difficulty in isolating these crystals for analysis, tissue sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to confirm the presence of hesperidin at the site of infection. The images constructed from MS/MS data with a specific diagnostic fragment ion (m/z 483) also showed higher ion intensities for it in infected plants than in healthy ones, mainly in the vessel regions. These data suggest that hesperidin plays a role in the plant-pathogen interaction, probably as a phytoanticipin. This method was also applied to C. sinensis and C. limonia seedlings, and comparison with the graft results showed that the rootstock had an increased hesperidin content ∼3.6 fold greater in the graft stem than in the stem of C. sinensis seedlings. Increase in hesperidin content by rootstock can be related to induced internal defense mechanisms.


Assuntos
Citrus/química , Hesperidina/análise , Xylella/patogenicidade , Cromatografia Líquida de Alta Pressão , Citrus/genética , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Caules de Planta/química , Rutina/análise , Xylella/efeitos dos fármacos
20.
Bioorg Med Chem ; 23(3): 466-70, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25564380

RESUMO

NS2B-NS3 is a serine protease of the Dengue virus considered a key target in the search for new antiviral drugs. In this study flavonoids were found to be inhibitors of NS2B-NS3 proteases of the Dengue virus serotypes 2 and 3 with IC50 values ranging from 15 to 44 µM. Agathisflavone (1) and myricetin (4) turned out to be noncompetitive inhibitors of dengue virus serotype 2 NS2B-NS3 protease with Ki values of 11 and 4.7 µM, respectively. Docking studies propose a binding mode of the flavonoids in a specific allosteric binding site of the enzyme. Analysis of biomolecular interactions of quercetin (5) with NT647-NHS-labeled Dengue virus serotype 3 NS2B-NS3 protease by microscale thermophoresis experiments, yielded a dissociation constant KD of 20 µM. Our results help to understand the mechanism of inhibition of the Dengue virus serine protease by flavonoids, which is essential for the development of improved inhibitors.


Assuntos
Vírus da Dengue/enzimologia , Flavonoides/farmacologia , Serina Endopeptidases/química , Inibidores de Serino Proteinase/química , Inibidores de Serino Proteinase/farmacologia , Antivirais/química , Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Flavonoides/química , Cinética , Modelos Moleculares , Simulação de Acoplamento Molecular , Serina Endopeptidases/metabolismo , Relação Estrutura-Atividade
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