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1.
Toxicol Lett ; 351: 1-9, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34407455

RESUMO

Tebuconazole (TEB) is a chiral triazole fungicide worldwide employed to control plant pathogens and preserve wood. People can be exposed to TEB either through diet and occupational contamination. This work investigates the in vitro inhibitory potential of rac-TEB, S-(+)-TEB, and R-(-)-TEB over the main cytochrome P450 enzymes (CYP450) using human liver microsomes to predict TEB in vivo inhibition potential. The IC50 values showed that in vitro inhibition was enantioselective for CYP2C9, CYP2C19, and CYP2D6, but not for CYP3A4/5. Despite enantioselectivity, rac-TEB and its single enantiomers were always classified in the same category. The inhibition mechanisms and constants were determined for rac-TEB and it has shown to be a mixed inhibitor of CYP3A4/5 (Ki = 1.3 ± 0.3 µM, αKi = 3.2 ± 0.5 µM; Ki = 0.6 ± 0.3 µM, αKi = 1.3 ± 0.3 µM) and CYP2C9 (Ki = 0.7 ± 0.1 µM, αKi = 2.7 ± 0.5 µM), and a competitive inhibitor of CYP2D6 (Ki = 11.9 ± 0.7 µM) and CYP2C19 (Ki = 0.23 ± 0.02 µM), respectively, suggesting that in some cases, rac-TEB has a higher or comparable inhibitory potential than well-known strong inhibitors of CYP450 enzymes, especially for CYP2C9 and CYP2C19. In vitro-in vivo extrapolations (IVIVE) were conducted based on the results and data available in the literature about TEB absorption and metabolism. R1 values were estimated based on the Food and Drug Administration guideline and suggested that in a chronic oral exposure scenario considering the acceptable daily intake dose proposed by the European Food and Safety Authority, the hypothesis of rac-TEB to inhibit the activities of CYP3A4/5, CYP2C9, and CYP2C19 in vivo and cause pesticide-drug interactions cannot be disregarded.


Assuntos
Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Praguicidas/farmacologia , Triazóis/química , Triazóis/farmacologia , Inibidores das Enzimas do Citocromo P-450/química , Humanos , Estrutura Molecular , Praguicidas/química , Relação Estrutura-Atividade
2.
Chem Biol Interact ; 345: 109552, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34147487

RESUMO

Ethofumesate is a chiral herbicide that may display enantioselective behavior in humans. For this reason, the enantioselective potential of ethofumesate and its main metabolite ethofumesate-2-hydroxy to cause pesticide-drug interactions on cytochrome P450 forms (CYPs) has been evaluated by using human liver microsomes. Among the evaluated CYPs, CYP2C19 had its activity decreased by the ethofumesate racemic mixture (rac-ETO), (+)-ethofumesate ((+)-ETO), and (-)-ethofumesate ((-)-ETO). CYP2C19 inhibition was not time-dependent, but a strong inhibition potential was observed for rac-ETO (IC50 = 5 ± 1 µmol L-1), (+)-ETO (IC50 = 1.6 ± 0.4 µmol L-1), and (-)-ETO (IC50 = 1.8 ± 0.4 µmol L-1). The reversible inhibition mechanism was competitive, and the inhibition constant (Ki) values for rac-ETO (2.6 ± 0.4 µmol L-1), (+)-ETO (1.5 ± 0.2 µmol L-1), and (-)-ETO (0.7 ± 0.1 µmol L-1) were comparable to the Ki values of strong CYP2C19 inhibitors. Inhibition of CYP2C19 by ethofumesate was enantioselective, being almost twice higher for (-)-ETO than for (+)-ETO, which indicates that this enantiomer may be a more potent inhibitor of this CYP form. For an in vitro-in vivo correlation, the Food and Drug Administration's (FDA) guideline on the assessment of drug-drug interactions used in the early stages of drug development was used. The FDA's R1 values were estimated on the basis of the obtained ethofumesate Ki and distribution volume, metabolism, unbound plasma fraction, gastrointestinal and dermal absorption data available in the literature. The correlation revealed that ethofumesate probably inhibits CYP2C19 in vivo for both chronic (oral) and occupational (dermal) exposure scenarios.


Assuntos
Benzofuranos/química , Benzofuranos/farmacologia , Inibidores do Citocromo P-450 CYP2C19/química , Inibidores do Citocromo P-450 CYP2C19/farmacologia , Citocromo P-450 CYP2C19/metabolismo , Mesilatos/química , Mesilatos/farmacologia , Praguicidas/química , Praguicidas/farmacologia , Citocromo P-450 CYP2C19/química , Inibidores do Citocromo P-450 CYP2C19/metabolismo , Relação Dose-Resposta a Droga , Descoberta de Drogas , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Estereoisomerismo
3.
J Chromatogr Sci ; 59(7): 597-605, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-33942054

RESUMO

Rifaximin, an antimicrobial used for the treatment of various diseases, lacks analytical methods in official compendia for evaluation of the final product. This paper presents an eco-friendly protocol for rifaximin tablets by high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The method was completely validated according to the International Conference on Harmonization guidelines and developed following the concept of Quality by Design. The separation was achieved using a C18 column, purified water +0.1% glacial acetic acid and ethyl alcohol, 52:48 (v/v), as mobile phase, 0.9 mL min-1 at 290 nm and ambient room temperature. Mass spectral analyses were performed using electrospray ionization (ESI) ion source and ion trap mass analyzer. The method was linear over the concentration range of 5-50 µg mL-1. The sample was subjected to acidic, basic, neutral, oxidative and photolytic degradation. Degradation products did not interfere in the quantification of the rifaximin, so the method can be considered indicative of stability. Degradation products were also evaluated individually by microbiological method using Escherichia coli. The validated method could be used promisingly as green analytical strategies for detection and quantification of rifaximin in tablets.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Rifaximina/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Estabilidade de Medicamentos , Escherichia coli/efeitos dos fármacos , Limite de Detecção , Nefelometria e Turbidimetria , Reprodutibilidade dos Testes , Rifaximina/química , Rifaximina/farmacologia , Comprimidos
4.
J Ocul Pharmacol Ther ; 37(5): 290-300, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33761287

RESUMO

Purpose: This study investigated the safety and therapeutic efficacy of licarin A (LCA) in the treatment of intraocular inflammation. Methods: In vitro safety of LCA in retinal pigmented epithelial cells (ARPE-19) and human embryonic stem cell derived-retinal pigmented epithelial cells (hES-RPE) was evaluated using CellTiter-Blue® kit. The chorioallantoic membrane (CAM) assay was used to investigate LCA safety and antiangiogenic activity. In vivo safety of intravitreal LCA was accomplished by clinical examination (including assessment of intraocular pressure), electroretinography (ERG), and histopathology. Uveitis was induced in rats by subcutaneous and intravitreal injection of bacillus Calmette-Guérin (BCG) antigen of Mycobacterium bovis. Intraocular inflammation was graded by slit-lamp and fundus examination, ERG, and histopathology. Results: LCA was safe to cells and to the CAM at concentration below 12.0 µM. LCA significantly reduced the percentage of blood vessels in the CAM. Retinal safety and anti-inflammatory efficacy of intravitreal injection of LCA 6.0 µM were confirmed through clinical, functional, and histopathological evaluation. Significant reduction of inflammatory cytokines (tumor necrosis factor-α and interleukin-6) was also found, when compared to untreated animals. Conclusion: The results suggest that LCA is a potential new drug for the treatment of inflammatory eye disease.

5.
Planta Med ; 87(1-02): 49-70, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33142347

RESUMO

"Blue Amazon" is used to designate the Brazilian Economic Exclusive Zone, which covers an area comparable in size to that of its green counterpart. Indeed, Brazil flaunts a coastline spanning 8000 km through tropical and temperate regions and hosting part of the organisms accredited for the country's megadiversity status. Still, biodiversity may be expressed at different scales of organization; besides species inventory, genetic characteristics of living beings and metabolic expression of their genes meet some of these other layers. These metabolites produced by terrestrial creatures traditionally and lately added to by those from marine organisms are recognized for their pharmaceutical value, since over 50% of small molecule-based medicines are related to natural products. Nonetheless, Brazil gives a modest contribution to the field of pharmacology and even less when considering marine pharmacology, which still lacks comprehensive in-depth assessments toward the bioactivity of marine compounds so far. Therefore, this review examined the last 40 years of Brazilian natural products research, focusing on molecules that evidenced anticancer potential-which represents ~ 15% of marine natural products isolated from Brazilian species. This review discusses the most promising compounds isolated from sponges, cnidarians, ascidians, and microbes in terms of their molecular targets and mechanisms of action. Wrapping up, the review delivers an outlook on the challenges that stand against developing groundbreaking natural products research in Brazil and on a means of surpassing these matters.


Assuntos
Biodiversidade , Produtos Biológicos , Organismos Aquáticos , Produtos Biológicos/farmacologia , Brasil
6.
Planta Med ; 87(1-02): 101-112, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33276406

RESUMO

Lychnophora ericoides is a Brazilian folk phytomedicine from Cerrado's "campus rupestris". Its volatile organic compounds includes bisabolene-derivatives as major compounds. Herein we provide the chemical profiling of constitutive volatile sesquiterpenes from L. ericoides leaves, timeframe emissions surveys, and pollinators records. In situ samples of L. ericoides were harvested. A headspace-solid phase micro extraction method of pre-concentration was optimized. Identification was done through GC-MS. Isolation and structural elucidation were performed whenever necessary. Pollinators were registered in pictures and video. Short time-series and harmonic regressions determined rhythms of single compounds, and average chromatographic signal area was used to determine mono and sesquiterpene rhythms. Concluding, optimized headspace-solid phase micro extraction method of terpenes level analysis was reached. α-Pinene, ß-pinene, α-terpinene, para-cymene, limonene, γ-terpinene, terpinen-4-ol, dehydro-sesquicineole, and ß-guaiene were identified using GC-MS data. 11-dehydro cadinol and ortho-acetoxy bisabolol were elucidated. Sesquiterpenes concentrations were higher due to temperature rise, lower leaf age, and flowering seasons. Harmonic regressions determined that daylight might control levels of terpenes. Hummingbird, hemiptera insects, and wasps were recorded visiting Compositae capitulum for the first time. We studied nondomestic plants from in situ conditions and concluded that bisabolene-derivative levels were more abundant than monoterpenes during flowering throughout the summer.


Assuntos
Arnica , Asteraceae , Óleos Voláteis , Sesquiterpenos , Brasil , Monoterpenos , Feromônios , Terpenos
7.
Food Chem Toxicol ; 146: 111826, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33127494

RESUMO

Fenamiphos (FS) is a chiral organophosphate pesticide that is used to control nematodes in several crops. Enantioselective differences may be observed in FS activity, bioaccumulation, metabolism, and toxicity. Humans may be exposed to FS through occupational and chronic (food, water, and environmental) exposure. FS may cause undesirable CYP450 pesticide-drug interactions, which may impact human health. Here, the CYP450 isoforms involved in enantioselective FS metabolism were identified, and CYP450 inhibition by rac-FS, (+)-FS, and (-)-FS was evaluated to obtain reliable information on enantioselective FS risk assessment in humans. CYP3A4 and CYP2E1 metabolized FS enantiomers, and CYP2B6 may participate in rac-FS metabolism. In addition, rac-FS, (+)-FS, and (-)-FS were reversible competitive CYP1A2, CYP2C19, and CYP3A4/5 inhibitors. High stereoselective inhibition potential was verified; rac-FS and (-)-FS strongly inhibited and (+)-FS moderately inhibited CYP1A2. Stereoselective differences were also detected for CYP2C19 and CYP3A4/5, which were strongly inhibited by rac-FS, (+)-FS, and (-)-FS. Our results indicated a high potential for CYP450 drug-pesticide interactions, which may affect human health. The lack of stereoselective research on the effect of chiral pesticides on the activity of CYP450 isoforms highlights the importance of assessing the risks of such pesticides in humans.


Assuntos
Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Isoenzimas/metabolismo , Compostos Organofosforados/metabolismo , Praguicidas/metabolismo , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Interações Medicamentosas , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/química , Isoenzimas/genética , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Compostos Organofosforados/toxicidade , Praguicidas/toxicidade , Proteínas Recombinantes
8.
Rapid Commun Mass Spectrom ; 34 Suppl 3: e8872, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32744732
9.
Molecules ; 25(15)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32751878

RESUMO

The mosquito species Aedes aegypti is one of the main vectors of arboviruses, including dengue, Zika and chikungunya. Considering the deficiency or absence of vaccines to prevent these diseases, vector control remains an important strategy. The use of plant natural product-based insecticides constitutes an alternative to chemical insecticides as they are degraded more easily and are less harmful to the environment, not to mention their lower toxicity to non-target insects. This review details plant species and their secondary metabolites that have demonstrated insecticidal properties (ovicidal, larvicidal, pupicidal, adulticidal, repellent and ovipositional effects) against the mosquito, together with their mechanisms of action. In particular, essential oils and some of their chemical constituents such as terpenoids and phenylpropanoids offer distinct advantages. Thiophenes, amides and alkaloids also possess high larvicidal and adulticidal activities, adding to the wealth of plant natural products with potential in vector control applications.


Assuntos
Aedes/efeitos dos fármacos , Infecções por Arbovirus/prevenção & controle , Arbovírus/fisiologia , Produtos Biológicos/farmacologia , Repelentes de Insetos/farmacologia , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos dos fármacos , Extratos Vegetais/farmacologia , Aedes/virologia , Animais , Infecções por Arbovirus/transmissão , Infecções por Arbovirus/virologia , Produtos Biológicos/química , Repelentes de Insetos/química , Inseticidas/química , Óleos Voláteis/farmacologia , Oviposição/efeitos dos fármacos , Extratos Vegetais/química
10.
Int J Mol Sci ; 21(13)2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32630308

RESUMO

Gliomas are responsible for more than 60% of all primary brain tumors. Glioblastoma multiforme (GBM), a grade IV tumor (WHO), is one of the most frequent and malignant gliomas. Despite two decades of advances in the discovery of new markers for GBM, the chemotherapy of choice falls to temozolomide after surgery and radiotherapy, which are not enough to increase the survival of patients to more than 15 months. It is urgent to discover new anti-glioma compounds. Many compounds derived from natural products have been used in the development of anti-tumor drugs. In this work, we have screened six low molecular weight sesquiterpene lactones, isolated from Eremanthus spp., and studied their function as anti-proliferative agents against GBM strains. We demonstrated that two of them, goyazensolide and lychnofolide, were effective in reducing cell viability, preventing the formation of anchorage-dependent colony and were able to pass through a mimetic blood-brain barrier making them candidates for glioma therapy, being more potent than temozolomide, according to in vitro assays for the cell lines tested. Proteomic analysis revealed a number of altered proteins involved in glycolytic metabolism and cellular catabolism.


Assuntos
Lactonas/farmacologia , Vernonia/metabolismo , Antineoplásicos/farmacologia , Asteraceae , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/metabolismo , Brasil , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Furanos/farmacologia , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , Lactonas/metabolismo , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Sesterterpenos/farmacologia , Vernonia/fisiologia
11.
Pharmaceutics ; 12(4)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32326277

RESUMO

A variety of neuroactive flavonoids can be found in the species of the Passiflora genus; however, their difficulty in crossing the blood-brain barrier limits their in vivo neuropharmacological activity. In this study, cationic nanoparticles were developed as a novel nanocarrier for improving the antidepressant activity of Passiflora edulis f. flavicarpa leaf extract. Formulations obtained using Eudragit E PO polymethylmethacrylate copolymer, as polymeric matrix had their physicochemical properties investigated. The analytical content of the flavonoids vicenin-2, orientin, isoorientin, vitexin, and isovitexin was determined in the plant extract. Small-sized and spherical nanoparticles loaded with Passiflora edulis f. flavicarpa were obtained with positive zeta potential and high encapsulation efficiency. In addition, the nanosystems were shown to be stable for at least 6 months. The antidepressant activity of P. edulis extract (50 and 100 mg/kg) as well as the extract-loaded nanoparticles (5 mg/kg) were investigated in mice using the forced swimming test, where the latter increased the potency of the former by 10-fold. In addition, histopathological and biochemical analysis confirmed the biocompatibility of the extract-loaded nanoparticles. This study demonstrated that the Eudragit cationic nanoparticles were able to improve the antidepressant activity of P. edulis in the central nervous system of mice.

13.
Planta Med ; 86(6): 415-424, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32126582

RESUMO

Ocotea fasciculata presents yangambin (YAN) and its isomer epi-yangambin (EPI-YAN) as major lignans, which are employed as the plant markers for quality control purposes and as potential pharmacological compounds. However, a gap between the pure isomers and safety and efficacy protocols is faced by the scientific community. In this context, this work aimed to report (i) a new and advantageous purifying process in a semi-preparative scale for YAN and EPI-YAN isolation from Ocotea fasciculata, and (ii) an in vitro cytotoxicity study to estimate, for the first time, the LD50 values of the isolated epimers, as well as the influence of albumin concentration in cell culture medium. The best condition for epimers isolation was achieved in normal-phase liquid chromatography. The lignan fraction (LF), previously obtained from the plant ethanolic extract, was purified yielding 17% and 29% of YAN and EPI-YAN, respectively. The in vitro study demonstrated that YAN and EPI-YAN were safe, and only at the highest concentration studied, a decrease on cell viability was observed. The estimated LD50 value was higher than 1612 mg/kg for both epimers. The LF, on the other hand, demonstrated an estimated LD50 of 422 mg/kg. Lignan cytotoxicity studies also evidenced that the higher cell viability was related to the higher concentration of fetal bovine serum as a source of albumin in medium. This is the first time the LD50 and safety of the isolated epimers were estimated, opening up great perspectives of success in in vivo studies.


Assuntos
Furanos , Lignanas , Ocotea , Extratos Vegetais
14.
Toxicol In Vitro ; 65: 104820, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32142840

RESUMO

Seriniquinone is a secondary metabolite isolated from a rare marine bacterium of the genus Serinicoccus. This natural quinone is highlighted for its selective cytotoxic activity toward melanoma cancer cells, in which rapid metastatic properties are still a challenge for clinical treatment of malignant melanoma. The progress of seriniquinone as a promising bioactive molecule for drug development requires the assessment of its clinical interaction potential with other drugs. This study aimed to investigate the in vitro inhibitory effects of seriniquinone on the main human CYP450 isoforms involved in drug metabolism. The results showed strong inhibition of CYP1A2, CYP2E1 and CYP3A, with IC50 values up to 1.4 µM, and moderate inhibition of CYP2C19, with IC50 value >15 µM. Detailed experiments performed with human liver microsomes showed that the inhibition of CYP450 isoforms can be explained by competitive and non-competitive inhibition mechanisms. In addition, seriniquinone demonstrated to be an irreversible and time-dependent inhibitor of CYP1A2 and CYP3A. The low inhibition constants values obtained experimentally suggest that concomitant intake of seriniquinone with drug metabolized by these isoforms should be carefully monitored for adverse effects or therapeutic failure.


Assuntos
Inibidores das Enzimas do Citocromo P-450/farmacologia , Quinonas/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Humanos , Microssomos Hepáticos/metabolismo
15.
Rapid Commun Mass Spectrom ; 34 Suppl 3: e8781, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32157723

RESUMO

RATIONALE: Clerodane-type diterpenes from Casearia species show important pharmacological activites such as antitumor, antimicrobial and anti-inflamatory. There are several mass spectrometry (MS)-based methods for identification of diterpenes; however, there is still a lack of MS procedures capable of providing characteristic fragmentation pathways for a rapid and unambiguous elucidation of casearin-like compounds. METHODS: Casearin-like compounds were investigated by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The fragmentation studies were carried out by tandem mass spectrometry in space (quadrupole time-of-flight (QTOF)) using different collision energies and also by tandem mass spectrometry in time (QIT) by selective isolation of product ions. RESULTS: Casearin-like compounds presented a predominance of sodium- and potassium-cationized precursor ions. Both QIT and QTOF techniques provided sequential neutral losses of esters related to the R1 to R5 substituents linked to the nucleus of the clerodane diterpenes. The fragmentation pathway is initiated with a cleavage of the ester moieties R2 followed by the elimination of the ester groups R3 , both losing neutral carboxylic acids. Using QIT, it was also possible to observe the cleavage of the ester groups R1 or R5 by MS4 experiments. CONCLUSIONS: Through a rational analysis of the fragmentation mechanisms of Casearia diterpenes it was possible to suggest an annotation strategy based on the sequential cleavages of the ester groups related to the R2 , R3 and R5 substituents. These results will assist studies of the dereplication and metabolomics involving casearin-like compounds present in complex extracts of Casearia species.


Assuntos
Casearia/química , Diterpenos Clerodânicos/análise , Diterpenos Clerodânicos/química , Espectrometria de Massas em Tandem/métodos , Extratos Vegetais/análise , Espectrometria de Massas por Ionização por Electrospray/métodos
16.
Anal Bioanal Chem ; 412(6): 1431-1439, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31912183

RESUMO

Triatominae are hematophagous insects involved in the transmission of Chagas disease. Among the 19 genera of the subfamily, those with the highest epidemiological importance regarding the dissemination of Trypanosoma cruzi are Panstrongylus, Rhodnius, and Triatoma. Of these three genera, Rhodnius presents the greatest difficulties for specific identification. Thus, there is a need to overcome the difficulties in identifying phenotypes of similar species of this genus. In the present study, the MALDI-TOF MS methodology was used to identify 12 Rhodnius species, among the 21 admitted. The MALDI-TOF MS methodology allowed specific characterization through the identification of peptides and proteins, starting from four different methods of extraction: (A) acetonitrile/formic acid (ACN/AF), (B) acetonitrile/trifluoroacetic acid (ACN/TFA), (C) isopropyl/formic acid (IPA/AF), and (D) methanol/formic acid (MeOH/AF), and four types of MALDI-TOF matrices: α-cyano-4-hydroxycinnamic acid (CHCA), sinapic acid (SA), 6-aza-2-thiothymine (ATT), and 2,6-dihydroxyacetophenone (DHAP). The experiments were performed by combining the four solvents and four matrices to select the best MALDI extraction/matrix. The application of the MALDI-TOF MS technique, through the digital mass spectrometry approach combined with chemometric tools, such as partial least squares-discriminant analysis (PLS-DA), was able to discriminate 12 species of Rhodnius genus, which are difficult to identify using morphological characteristics. Thus, in view of the results obtained, the methodology described in the present article can be applied with speed and efficiency for the discrimination of Triatominae species. Graphical Abstract.


Assuntos
Proteínas de Insetos/química , Peptídeos/química , Rhodnius/classificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Acetofenonas/química , Animais , Ácidos Cumáricos/química , Formiatos/química
17.
Rapid Commun Mass Spectrom ; 34 Suppl 3: e8533, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31330071

RESUMO

RATIONALE: Aporphine alkaloids represent a large group of isoquinoline natural products with important roles in biological and biomedical areas. Their characterization by electrospray ionization tandem mass spectrometry (ESI-MS/MS) can contribute to their rapid identification in complex biological matrices. METHODS: We report the fragmentation of protonated 7,7-dimethylaporphine alkaloids by ESI-MS/MS, and the putative annotation of aporphine alkaloids in plant extracts. We used low- and high-resolution MS/MS analyses to rationalize the fragmentation pathways, and employed the B3LYP/6-31 + G(d,p) density functional theory (DFT) model to provide thermochemical parameters and to obtain the reactive sites. RESULTS: DFT calculations of a set of 7,7-dimethylaporphine alkaloids suggested the heterocyclic amino group as the most basic site due to the proton affinity of the nitrogen atom. Collision-induced dissociation experiments promoted • OCH3 elimination instead of the expected neutral loss of the heterocyclic amino group, pointing to the [M - 15 + H]•+ ion as the diagnostic fragment for 7,7-dimethylaporphine alkaloids. The analysis of plant extracts led to the annotation of 25 aporphine alkaloids. Their fragmentation initiated with the loss of the amino group followed by formation of a cyclic carbocation. Further reactions derived from consecutive charge-remote and/or charge-induced fragmentations of the substituents attached to the aromatic system. The mechanisms were re-examined based on plausible gas-phase ion chemistry reactions. CONCLUSIONS: Taken together, the diagnostic product ions and the series of radical and neutral eliminations provided information about the location of methylenedioxy, aromatic methoxy, and vicinal methoxy and hydroxy groups in aporphine alkaloids, assisting their characterization via MS/MS.

18.
Nat Prod Res ; 34(7): 995-1001, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30584781

RESUMO

Ethanol extracts of different parts of Passiflora cincinnata were obtained by maceration. The total phenolic and flavonoid contents were evaluated. The antioxidant activities were determined by ß-carotene-linoleic acid bleaching test, 2,2-diphenyl-1-picrylhydrazil (DPPH), and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging. The crude ethanol stem extract showed the highest amount of total polyphenols (45.53 mg gallic acid equivalent/g) while the highest total flavonoid contents (1.42 mg of quercetin equivalent/g) were observed in the leaf extract. The lowest IC50 (25.65 µg/ml) by the DPPH method was observed for the stem extract. The ABTS method showed a significant antioxidant activity for all investigated extracts. The secondary metabolite composition of ethanol extracts was assessed by HPLC-DAD-MS/MS analysis, leading to the identification of fourteen secondary metabolites in P. cincinnata extracts. These results showed the potentiality of this species as a source of phenolic compounds and antioxidants.


Assuntos
Antioxidantes/química , Flavonoides/análise , Passiflora/química , Fenóis/análise , Extratos Vegetais/química , Metabolismo Secundário , Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/química , Polifenóis/análise , Quercetina/análise , Espectrometria de Massas em Tandem/métodos
19.
Biochem Biophys Res Commun ; 521(3): 674-680, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31685208

RESUMO

Galectin-3 (Gal-3) is a multifunctional glycan-binding protein that participates in many pathophysiological events and has been described as a biomarker and potential therapeutic target for severe disorders, such as cancer. Several probes for Gal-3 or its ligands have been developed, however both the pathophysiological mechanisms and potential biomedical applications of Gal-3 remain not fully assessed. Molecular imaging using bioluminescent probes provides great sensitivity for in vivo and in vitro analysis for both cellular and whole multicellular organism tracking and target detection. Here, we engineered a chimeric molecule consisting of Renilla luciferase fused with mouse Gal-3 (RLuc-mGal-3). RLuc-mGal-3 preparation was highly homogenous, soluble, active, and has molecular mass of 65,870.95 Da. This molecule was able to bind to MKN45 cell surface, property which was inhibited by the reduction of Gal-3 ligands on the cell surface by the overexpression of ST6GalNAc-I. In order to obtain an efficient and stable delivery system, RLuc-mGal-3 was adsorbed to poly-lactic acid nanoparticles, which increased binding to MKN45 cells in vitro. Furthermore, bioluminescence imaging showed that RLuc-mGal-3 was able to indicate the presence of implanted tumor in mice, event drastically inhibited by the presence of lactose. This novel bioluminescent chimeric molecule offers a safe and highly sensitive alternative to fluorescent and radiolabeled probes with potential application in biomedical research for a better understanding of the distribution and fate of Gal-3 and its ligands in vitro and in vivo.


Assuntos
Galectina 3/metabolismo , Luciferases de Renilla/metabolismo , Substâncias Luminescentes/metabolismo , Neoplasias/diagnóstico por imagem , Polissacarídeos/metabolismo , Animais , Linhagem Celular Tumoral , Galectina 3/análise , Galectina 3/genética , Humanos , Luciferases de Renilla/análise , Luciferases de Renilla/genética , Substâncias Luminescentes/análise , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/metabolismo , Imagem Óptica , Polissacarídeos/análise , Ligação Proteica , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
20.
Int J Pharm ; 574: 118872, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31812797

RESUMO

Medical devices (indwelling) have greatly improved healthcare. Nevertheless, infections related to the use of these apparatuses continue to be a major clinical concern. Biofilms form on surfaces after bacterial adhesion, and they function as bacterial reservoirs and as resistance and tolerance factors against antibiotics and the host immune response. Technological strategies to control biofilms and bacterial adhesion, such as the use of surface coatings, are being explored more frequently, and natural peptides may promote their development. In this study, we purified and identified antibiofilm peptides from Capsicum baccatum (red pepper) using chromatography-tandem mass spectrometry, MALDI-MS, MS/MS and bioinformatics. These peptides strongly controlled biofilm formation by Staphylococcus epidermidis, the most prevalent pathogen in device-related infections, without any antibiotic activity. Furthermore, natural peptide-coated surfaces dislayed effective antiadhesive proprieties and showed no cytotoxic effects against different representative human cell lines. Finally, we determined the lead peptide predicted by Mascot and identified CSP37, which may be useful as a prime structure for the design of new antibiofilm agents. Together, these results shed light on natural Capsicum peptides as a possible antiadhesive coat to prevent medical device colonization.


Assuntos
Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Capsicum/química , Peptídeos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus epidermidis/efeitos dos fármacos , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis/química , Células HCT116 , Humanos , Células MCF-7 , Células PC-3 , Espectrometria de Massas em Tandem/métodos
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