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1.
Plant Physiol Biochem ; 206: 108310, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38169226

RESUMO

Hybanthus enneaspermus (L.)F.Muell. is a highly indispensable medicinal herb yielding L-Dopa, deemed the gold standard drug among the therapeutic options for Parkinson's disease. This investigation is the first attempt to evaluate the eliciting influence of carboxylic acid functionalized multi-walled carbon nanotube (MWCNT-COOH) on the biosynthesis of L-Dopa and on biomass aggregation and antioxidant metabolites in H. enneaspermus cell suspension cultures. Suspension cells were accomplished from friable calli generated from the nodal segments of H. enneaspermus in Murashige and Skoog (MS) liquid medium infused with 2 mg L-1 2, 4-Dichlorophenoxyacetic acid (2, 4-D), and 0.3 mg L-1meta-Topolin (mT). The influence of MWCNTs on L-Dopa synthesis, biomass accumulation, and biochemical parameters was examined on the basis of the exposure time and in a concentration-dependent manner of MWCNTs. The inclusion of 30 mg L-1 MWCNTs increased the biomass and the L-Dopa level by 2.00 and 16.37-folds, respectively, compared with that of the control. Furthermore, the effect of MWCNTs on physiological parameters such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), ascorbate peroxidase (APX), hydrogen peroxide (H2O2), malondialdehyde (MDA) content, 2-diphenylpicrylhydrazyl (DPPH), and ferric-reducing ability of plasma (FRAP) was examined over the elicited cells. Among the antioxidant enzymatic activities, CAT enhanced 8.0 fold compared with that of the control. MDA and DPPH content enhanced 2.60 and 1.12 folds, respectively, compared with that of the control. The current study showed that MWCNTs offer new possibilities for their usage over in vitro by acting as potential innovative plant metabolite elicitors and stress-protecting entities.


Assuntos
Nanotubos de Carbono , Violaceae , Antioxidantes/metabolismo , Levodopa , Peróxido de Hidrogênio/metabolismo , Violaceae/química , Violaceae/metabolismo
2.
J Nat Prod ; 85(9): 2127-2134, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36044031

RESUMO

Cyclotides are mini-proteins with potent bioactivities and outstanding potential for agricultural and pharmaceutical applications. More than 450 different plant cyclotides have been isolated from six angiosperm families. In Brazil, studies involving this class of natural products are still scarce, despite its rich floristic diversity. Herein were investigated the cyclotides from Anchietea pyrifolia roots, a South American medicinal plant from the family Violaceae. Fourteen putative cyclotides were annotated by LC-MS. Among these, three new bracelet cyclotides, anpy A-C, and the known cycloviolacins O4 (cyO4) and O17 (cyO17) were sequenced through a combination of chemical and enzymatic reactions followed by MALDI-MS/MS analysis. Their cytotoxic activity was evaluated by a cytotoxicity assay against three human cancer cell lines (colorectal carcinoma cells: HCT 116 and HCT 116 TP53-/- and breast adenocarcinoma, MCF 7). For all assays, the IC50 values of isolated compounds ranged between 0.8 and 7.3 µM. CyO17 was the most potent cyclotide for the colorectal cancer cell lines (IC50, 0.8 and 1.2 µM). Furthermore, the hemolytic activity of anpy A and B, cyO4, and cyO17 was assessed, and the cycloviolacins were the least hemolytic (HD50 > 156 µM). This work sheds light on the cytotoxic effects of the anpy cyclotides against cancer cells. Moreover, this study expands the number of cyclotides obtained to date from Brazilian plant biodiversity and adds one more genus containing these molecules to the list of the Violaceae family.


Assuntos
Produtos Biológicos , Ciclotídeos , Proteínas de Plantas , Violaceae , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Brasil , Linhagem Celular Tumoral , Ciclotídeos/química , Ciclotídeos/isolamento & purificação , Ciclotídeos/farmacologia , Humanos , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Espectrometria de Massas em Tandem , Violaceae/química
3.
J Biol Chem ; 298(10): 102413, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36007611

RESUMO

Cyclotides and acyclic versions of cyclotides (acyclotides) are peptides involved in plant defense. These peptides contain a cystine knot motif formed by three interlocked disulfide bonds, with the main difference between the two classes being the presence or absence of a cyclic backbone, respectively. The insecticidal activity of cyclotides is well documented, but no study to date explores the insecticidal activity of acyclotides. Here, we present the first in vivo evaluation of the insecticidal activity of acyclotides from Rinorea bengalensis on the vinegar fly Drosophila melanogaster. Of a group of structurally comparable acyclotides, ribe 31 showed the most potent toxicity when fed to D. melanogaster. We screened a range of acyclotides and cyclotides and found their toxicity toward human red blood cells was substantially lower than toward insect cells, highlighting their selectivity and potential for use as bioinsecticides. Our confocal microscopy experiments indicated their cytotoxicity is likely mediated via membrane disruption. Furthermore, our surface plasmon resonance studies suggested ribe 31 preferentially binds to membranes containing phospholipids with phosphatidyl-ethanolamine headgroups. Despite having an acyclic backbone, we determined the three-dimensional NMR solution structure of ribe 31 is similar to that of cyclotides. In summary, our results suggest that, with further optimization, ribe 31 could have applications as an insecticide due to its potent in vivo activity against D. melanogaster. More broadly, this work advances the field by demonstrating that acyclotides are more common than previously thought, have potent insecticidal activity, and have the advantage of potentially being more easily manufactured than cyclotides.


Assuntos
Ciclotídeos , Drosophila melanogaster , Inseticidas , Proteínas de Plantas , Violaceae , Animais , Humanos , Sequência de Aminoácidos , Ciclotídeos/química , Ciclotídeos/isolamento & purificação , Ciclotídeos/farmacologia , Drosophila melanogaster/efeitos dos fármacos , Inseticidas/química , Inseticidas/isolamento & purificação , Inseticidas/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Violaceae/química , Eritrócitos/efeitos dos fármacos
4.
J Nat Prod ; 84(2): 395-407, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33570395

RESUMO

Cyclotides are plant-derived peptides that have attracted interest as biocides and scaffolds for the development of stable peptide therapeutics. Cyclotides are characterized by their cyclic backbone and cystine knot framework, which engenders them with remarkably high stability. This study reports the cystine knot-related peptidome of Rinorea bengalensis, a small rainforest tree in the Violaceae family that is distributed from Australia westward to India. Surprisingly, many more acyclic knotted peptides (acyclotides) were discovered than cyclic counterparts (cyclotides), with 32 acyclotides and 1 cyclotide sequenced using combined transcriptome and proteomic analyses. Nine acyclotides were isolated and screened against a panel of mammalian cell lines, showing they had the cytotoxic properties normally associated with cyclotide-like peptides. NMR analysis of the acyclotide ribes 21 and 22 and the cyclotide ribe 33 confirmed that these peptides contained the cystine knot structural motif. The bracelet-subfamily cyclotide ribe 33 was amenable to chemical synthesis in reasonable yield, an achievement that has long eluded previous attempts to synthetically produce bracelet cyclotides. Accordingly, ribe 33 represents an exciting new bracelet cyclotide scaffold that can be subject to chemical modification for future molecular engineering applications.


Assuntos
Ciclotídeos/síntese química , Cistina/química , Violaceae/química , Linhagem Celular Tumoral , Ciclotídeos/química , Eritrócitos/efeitos dos fármacos , Humanos , Extratos Vegetais/química , Proteínas de Plantas/química , Proteômica , Queensland , Transcriptoma
5.
J Nat Prod ; 84(1): 81-90, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33397096

RESUMO

Cyclotides are plant-derived peptides found within five families of flowering plants (Violaceae, Rubiaceae, Fabaceae, Solanaceae, and Poaceae) that have a cyclic backbone and six conserved cysteine residues linked by disulfide bonds. Their presence within the Violaceae species seems ubiquitous, yet not all members of other families produce these macrocyclic peptides. The genus Palicourea Aubl. (Rubiaceae) contains hundreds of neotropical species of shrubs and small trees; however, only a few cyclotides have been discovered hitherto. Herein, five previously uncharacterized Möbius cyclotides within Palicourea sessilis and their pharmacological activities are described. Cyclotides were isolated from leaves and stems of this plant and identified as pase A-E, as well as the known peptide kalata S. Cyclotides were de novo sequenced by MALDI-TOF/TOF mass spectrometry, and their structures were solved by NMR spectroscopy. Because some cyclotides have been reported to modulate immune cells, pase A-D were assayed for cell proliferation of human primary activated T lymphocytes, and the results showed a dose-dependent antiproliferative function. The toxicity on other nonimmune cells was also assessed. This study reveals that pase cyclotides have potential for applications as immunosuppressants and in immune-related disorders.


Assuntos
Ciclotídeos/efeitos dos fármacos , Ciclotídeos/metabolismo , Fabaceae/química , Linfócitos/metabolismo , Solanaceae/química , Violaceae/química , Brasil , Ciclotídeos/química , Humanos , Linfócitos/química , Linfócitos/efeitos dos fármacos , Magnoliopsida , Espectrometria de Massas , Folhas de Planta/química , Folhas de Planta/metabolismo
6.
J Nat Prod ; 83(12): 3736-3743, 2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33296204

RESUMO

Hybanthus enneaspermus is an Indian folk medicinal herb that has been widely used as a libido enhancer. This plant belongs to the Violaceae plant family, which ubiquitously contains disulfide-rich cyclic peptides named cyclotides. Cyclotides are an expanding plant-derived peptide family with numerous interesting bioactivities, and their unusual stability against proteolysis has attracted much attention in drug design applications. Recently, H. enneaspermus has been reported to be a rich source of cyclotides, and hence, it was of interest to investigate whether cyclotides contribute to its aphrodisiac activity. In this study, we evaluated the in vivo aphrodisiac activity of the herbal powder, extract, and the most abundant cyclotide, hyen D, extracted from H. enneaspermus on rats in a single dose regimen. After dosing, the sexual behaviors of male rats were observed, recorded, analyzed, and compared with those of the vehicle group. The results show that the extract and hyen D significantly decreased the intromission latency of sexually naïve male rats and the extract improved a range of other measured sexual parameters. The results suggest that the extract could enhance libido as well as facilitate erectile function in male rats and that the cyclotide hyen D could contribute to the libido-enhancing activity of this ethnomedicinal herb.


Assuntos
Afrodisíacos/farmacologia , Extratos Vegetais/farmacologia , Violaceae/química , Animais , Feminino , Masculino , Ratos , Comportamento Sexual Animal
7.
J Biol Chem ; 295(32): 10911-10925, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32414842

RESUMO

Cyclotides are plant-derived peptides characterized by an ∼30-amino acid-long cyclic backbone and a cystine knot motif. Cyclotides have diverse bioactivities, and their cytotoxicity has attracted significant attention for its potential anticancer applications. Hybanthus enneaspermus (Linn) F. Muell is a medicinal herb widely used in India as a libido enhancer, and a previous study has reported that it may contain cyclotides. In the current study, we isolated 11 novel cyclotides and 1 known cyclotide (cycloviolacin O2) from H. enneaspermus and used tandem MS to determine their amino acid sequences. We found that among these cyclotides, hyen C comprises a unique sequence in loops 1, 2, 3, 4, and 6 compared with known cyclotides. The most abundant cyclotide in this plant, hyen D, had anticancer activity comparable to that of cycloviolacin O2, one of the most cytotoxic known cyclotides. We also provide mechanistic insights into how these novel cyclotides interact with and permeabilize cell membranes. Results from surface plasmon resonance experiments revealed that hyen D, E, L, and M and cycloviolacin O2 preferentially interact with model lipid membranes that contain phospholipids with phosphatidyl-ethanolamine headgroups. The results of a lactate dehydrogenase assay indicated that exposure to these cyclotides compromises cell membrane integrity. Using live-cell imaging, we show that hyen D induces rapid membrane blebbing and cell necrosis. Cyclotide-membrane interactions correlated with the observed cytotoxicity, suggesting that membrane permeabilization and disintegration underpin cyclotide cytotoxicity. These findings broaden our knowledge on the indigenous Indian herb H. enneaspermus and have uncovered cyclotides with potential anticancer activity.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ciclotídeos/farmacologia , Descoberta de Drogas , Plantas Medicinais/química , Violaceae/química , Sequência de Aminoácidos , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Ciclotídeos/química , Ciclotídeos/isolamento & purificação , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Ressonância de Plasmônio de Superfície , Espectrometria de Massas em Tandem
8.
Nat Prod Res ; 34(14): 2014-2021, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30784307

RESUMO

Two new coruleoellagic acid derivatives, 3,4',5,5',-tetramethylcoruleoellagic acid (1); 3',4,4',5,5'-pentamethylcoruleoellagic acid (2) and a new friedelane-type triterpene derivative rinol (5), were isolated from leaves and trunk bark of Rinorea oblongifolia (Violaceae) along with seven known compounds including 3,3',4,4',5'-pentamethylcoruleoellagic acid (3), hexamethylcoruleoellagic acid (4), 28-hydroxyfriedelin (6), friedelin (7), friedelan-3-ol (8), scopoletin (9) and ß-sitosterol-3-O-ß-D-glucopyranoside (10). Their structures were elucidated by means of spectroscopic methods including IR, 1D and 2D NMR in conjunction with mass spectrometry. Crude extracts of leaves and trunk bark as well as compounds 1-4 were evaluated for their antibacterial activities against 7 pathogenic bacterial strains (Streptococcus pneumoniae ATCC49619, Staphylococcus aureus ATCC 43300, Klepsiella pneumoniae ATCC 700603, Haemophilus influenza ATCC 49247, Escherichia coli ATCC 25922, Pseudomonas aeruginosa HM601, Staphylococcus aureus BAA 977). Compound (3) displayed noteworthy activity against Haemophilus influenza with MIC value of 9.38 µg/mL.


Assuntos
Antibacterianos/isolamento & purificação , Casca de Planta/química , Folhas de Planta/química , Violaceae/química , Antibacterianos/química , Bactérias/efeitos dos fármacos , Haemophilus influenzae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Triterpenos/análise , Triterpenos/isolamento & purificação
9.
J Med Food ; 22(4): 393-407, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30990753

RESUMO

Although leaves of Anchietea salutaris are used in Brazilian traditional medicine, there is no available data in the literature proving its efficacy and safety. Thus, the aim of the study was to perform a meticulous botanical, phytochemical, toxicological, and pharmacological investigation of A. salutaris in Wistar rats. At first, a morphoanatomical characterization of Anchietea pyrifolia leaves and stems was performed. Then, a purified infusion (ethanol-soluble fraction obtained from A. pyrifolia [ESAP]) was obtained followed by its chemical profile elucidation. Furthermore, an acute toxicity test was performed, and the acute and prolonged diuretic and hypotensive effects were also evaluated in Wistar rats. Finally, the vasodilatory responses of ESAP in mesenteric vascular beds were investigated. The main secondary metabolites identified from ESAP were O-glycosylated flavonoids, chlorogenic acids, and phenylpropanoic acid derivatives. ESAP did not promote any toxic effects in female rats nor increased urinary excretion in male rats after a single exposure. However, ESAP significantly reduced renal elimination of sodium, potassium, and chloride after prolonged treatment. An ESAP highest dose promoted significant acute hypotension without affecting blood pressure levels after prolonged use. Furthermore, its cardiovascular effects seem to be related with the calcium-activated potassium channel activation in resistance vessels.


Assuntos
Anti-Hipertensivos/administração & dosagem , Hipertensão/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Violaceae/química , Animais , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/química , Pressão Sanguínea/efeitos dos fármacos , Brasil , Diuréticos/administração & dosagem , Diuréticos/efeitos adversos , Diuréticos/química , Feminino , Humanos , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Extratos Vegetais/efeitos adversos , Extratos Vegetais/química , Folhas de Planta/química , Canais de Potássio Cálcio-Ativados/genética , Canais de Potássio Cálcio-Ativados/metabolismo , Ratos Wistar
10.
J Nat Prod ; 81(11): 2512-2520, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30387611

RESUMO

Cyclotides are macrocyclic cystine-knotted peptides most commonly found in the Violaceae plant family. Although Rinorea is the second-largest genera within the Violaceae family, few studies have examined whether or not they contain cyclotides. To further our understanding of cyclotide diversity and evolution, we examined the cyclotide content of two Rinorea species found in Southeast Asia: R. virgata and R. bengalensis. Seven cyclotides were isolated from R. virgata (named Rivi1-7), and a known cyclotide (cT10) was found in R. bengalensis. Loops 2, 5, and 6 of Rivi1-4 contained sequences not previously seen in corresponding loops of known cyclotides, thereby expanding our understanding of the diversity of cyclotides. In addition, the sequence of loop 2 of Rivi3 and Rivi4 were identical to some related noncyclic "acyclotides" from the Poaceae plant family. As only acyclotides, but not cyclotides, have been reported in monocotyledons thus far, our findings support an evolutionary link between monocotyledon-derived ancestral cyclotide precursors and dicotyledon-derived cyclotides. Furthermore, Rivi2 and Rivi3 had comparable cytotoxic activities to the most cytotoxic cyclotide known to date: cycloviolacin O2 from Viola odorata; yet, unlike cycloviolacin O2, they did not show hemolytic activity. Therefore, these cyclotides represent novel scaffolds for use in future anticancer drug design.


Assuntos
Ciclotídeos/química , Violaceae/química , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Extratos Vegetais/química , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
11.
Planta Med ; 84(12-13): 947-952, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29843182

RESUMO

Biologically active cyclotides have been found on some flowering plants species and are involved in the role of the plant protection. As part of studies focusing on peptides from Brazilian plant species, we are reporting the detection by LC-MS of several cyclotides from leaves and stems of Noisettia orchidiflora (Violaceae). From stems it was possible to isolate and characterize a cyclotide named Nor A. Its primary structure (amino acid sequence) was established by MALDI-TOF-MS, based on the y- and b-type ion series, after reduction and alkylation reactions, as well as enzymatic digestion using the enzymes endoproteinase glutamic acid (endoGlu-C), trypsin, and chymotrypsin. Furthermore, the amino acid analysis was also described.


Assuntos
Ciclotídeos/isolamento & purificação , Violaceae/química , Sequência de Aminoácidos , Cromatografia Líquida , Ciclotídeos/química , Folhas de Planta/química , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Caules de Planta/química , Alinhamento de Sequência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
12.
Fish Shellfish Immunol ; 68: 310-317, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28688911

RESUMO

This study evaluated the effects of Hybanthus enneaspermus aqueous extract (HEE) as a feed supplement on growth, immune responses, haematological, and biochemical parameters of Labeo rohita and its susceptibility to Aeromonas hydrophila infection. Diets containing five variable concentrations of HEE (g kg-1) (0 [basal diet], 1.0 [H1], 2.0 [H2], 3.0 [H3], and 4.0 [H4]) were fed to fish (average weight: 17.2 ± 0.21 g) for 6 weeks. Growth parameters, immune parameters, and haemato-biochemical parameters were examined 6 weeks post-feeding. The results showed that growth parameters, such as final weight (39.47 ± 3.1 g) and specific growth rate (1.92 ± 0.2), were significantly higher in the H3 group than in the control. Immunological parameters such as serum lysozyme (24.73 ± 2.16 U mg-1), phagocytic activity (19.14± 0.26%), and respiratory burst activity (0.307 ± 0.005) were significantly higher in the H3 group, compared with the control. Among the haematological parameters examined, red blood cells, white blood cells, neutrophils, total serum protein, and albumin levels were significantly higher in the H3 group. However, HEE administration had no significant effect on haematocrit, haemoglobin, monocytes, or eosinophils levels. Blood biochemical parameters, including superoxide dismutase and alkaline phosphatase activities, were higher (P < 0.05) in the H3 group than in the control; however, the opposite result was found for aspartate transaminase, alanine transaminase, glucose, and cholesterol. Supplementation with 3 g kg-1 HEE increased the activities of intestinal digestive enzyme (amylase, protease, and lipase) in fish. Moreover, fish fed diets supplemented with 3 g kg-1 HEE exhibited the highest disease resistance against A. hydrophila infection. These results suggest that dietary administration of HEE (at 3 g kg-1) has several positive effects on growth, immune and haematological responses in L. rohita.


Assuntos
Cyprinidae/crescimento & desenvolvimento , Cyprinidae/imunologia , Suplementos Nutricionais , Doenças dos Peixes/imunologia , Imunidade Inata , Extratos Vegetais/metabolismo , Violaceae/química , Aeromonas hydrophila/imunologia , Ração Animal/análise , Animais , Cyprinidae/sangue , Dieta/veterinária , Resistência à Doença , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Distribuição Aleatória
13.
Chem Commun (Camb) ; 53(53): 7337-7340, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28508909

RESUMO

A simple MD-based protocol is presented to accurately predict both the sequence and order of disulfide bond formation in proteins containing multiple cysteine residues. It provides a detailed description of their dynamical and structural features, which can be used to perform ensemble-averaged ECD calculations. Plant cyclotides are used as model compounds.


Assuntos
Ciclotídeos/química , Cisteína/química , Dissulfetos/química , Dicroísmo Circular , Simulação de Dinâmica Molecular , Termodinâmica , Violaceae/química
14.
J Nat Prod ; 80(5): 1522-1530, 2017 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-28471681

RESUMO

Cyclotides are a large family of naturally occurring plant-derived macrocyclic cystine-knot peptides, with more than 400 having been identified in species from the Violaceae, Rubiaceae, Cucurbitaceae, Fabaceae, and Solanaceae families. Nevertheless, their specialized distribution within the plant kingdom remains poorly understood. In this study, the diversity of cyclotides was explored through the screening of 197 plants belonging to 43 different families. In total, 28 cyclotides were sequenced from 15 plant species, one of which belonged to the Rubiaceae and 14 to the Violaceae. Every Violaceae species screened contained cyclotides, but they were only sparsely represented in Rubiaceae and nonexistent in other families. The study thus supports the hypothesis that cyclotides are ubiquitous in the Violaceae, and it adds to the list of plants found to express kalata S and cycloviolacin O12. Finally, previous studies suggested the existence of cyclotide isoforms with either an Asn or an Asp at the C-terminal processing site of the cyclotide domain within the precursor proteins. Here we found that despite the discovery of a few cyclotides genuinely containing an Asp in loop 6 as evidenced by gene sequencing, deamidation of Asn during enzymatic digestion resulted in the artifactual presence of Asp isoforms. This result is consistent with studies suggesting that peptides can undergo deamidation after being subjected to external factors, including pH, temperature, and enzymatic digestion.


Assuntos
Ciclotídeos/isolamento & purificação , Cistina/isolamento & purificação , Fabaceae/química , Proteínas de Plantas/isolamento & purificação , Rubiaceae/química , Solanaceae/química , Violaceae/química , Sequência de Aminoácidos , Ciclotídeos/química , Cistina/química , Estrutura Molecular , Proteínas de Plantas/química
15.
Carbohydr Polym ; 149: 391-8, 2016 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-27261763

RESUMO

A polysaccharide was extracted from the roots of Pombalia calceolaria, a plant used in folk medicine in Northeastern Brazil, by decoction followed by precipitation with methanol, yielding a concentration of 13.0% w/w, and purification with acetone. The molar mass peak was estimated to be 4.0×10(3)Da using gel permeation chromatography (GPC). Polarized light photomicrography of histological sections revealed the presence of inulin in the cortical parenchyma. The chemical composition of inulin was identified by 1D and 2D NMR and FT-IR spectroscopy and the findings were compared with the literature. This is the first time inulin has been identified on FT-IR and NMR for the species Pombalia calceolaria.


Assuntos
Inulina/análise , Raízes de Plantas/química , Violaceae/química , Inulina/química , Inulina/isolamento & purificação
16.
J Ethnopharmacol ; 179: 83-91, 2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26721222

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: People living in the tropical rain forest of South-Western Nigeria use Rinorea dentata (P. Beauv.) Kuntze (Violaceae) in ethno-veterinary medicine to facilitate parturition. There are no evidence-based pharmacological investigations for the uterotonic activity of this plant. AIMS OF STUDY: (i) Collection of data about the ethnopharmacological uses of R. dentata and evaluation of its uses and applications in health care; (ii) determining potential uterotonic effects in vitro, and (iii) chemical characterization of R. dentata, which is a member of the Violaceae family known to express circular cystine-knot peptides, called cyclotides. MATERIALS AND METHODS: The ethnopharmacological use of R. dentata in settlement camps within the area J4 of Omo forest has been investigated by semi-structured questionnaires and open interviews. Use index analysis has been performed by seven quantitative statistical models. Respondents' claim on the beneficial ethno-veterinary application of the plant to aid parturition has been investigated in vitro by myometrial contractility organ bath assays. The bioactive plant extract was screened by chemical derivatization and mass spectrometry-based peptidomics using reversed-phase HPLC fractionation and MALDI-TOF/TOF analysis. RESULTS: Based on the survey analysis, medicinal preparations of R. dentata have been used for anti-microbial and anti-malaria purpose in humans, and for aiding parturition in farm animals. The latter application was mentioned by one out of six respondents who claimed to use this plant for any medicinal purpose. The plant extract exhibited a weak uterotonic effect using organ bath studies. The plant contains cyclotides and the peptide riden A has been identified by de novo amino acid sequencing using mass spectrometry. CONCLUSION: Few dwellers around the settlement camps of the tropical forest of Omo (Nigeria) use R. dentata for various health problems in traditional veterinary and human medicine. The weak uterotonic effect of the cyclotide-rich extract is in agreement with the low use value index obtained for this plant. Cyclotides have been reported in the genus Rinorea confirming the ubiquitous expression of these stable bioactive plant peptides within the family of Violaceae.


Assuntos
Ciclotídeos/química , Medicinas Tradicionais Africanas , Violaceae/química , Animais , Animais Domésticos , Anti-Infecciosos/uso terapêutico , Antimaláricos/uso terapêutico , Etnofarmacologia , Feminino , Humanos , Técnicas In Vitro , Miométrio/efeitos dos fármacos , Nigéria , Ocitócicos/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Gravidez , Inquéritos e Questionários , Útero/efeitos dos fármacos
17.
Environ Sci Pollut Res Int ; 23(3): 2705-14, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26438369

RESUMO

Green synthesis of silver nanoparticles (AgNPs) using Hybanthus enneaspermus extract at room temperature that act as a reducing agent as well as capping agent has been investigated. The synthesized AgNPs were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), zeta potential, and dynamic light scattering (DLS) transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX). The silver surface plasmon resonance was observed at 420 nm in the UV-visible spectrum. XRD peaks were observed at 2θ values in 38.20°, 44.40°, 64.60°, and 77.50° which are indexed as (111), (200), (220), and (311) bands of face-centered cubic (fcc) structures of silver. FTIR revealed the AgNPs were capped with plant compounds of alcohol, phenols, carbonyl, amines, and amide functional groups. TEM image shows that the particles were of spherical, hexagonal, and triangular in shape, and the size range was 16-26 nm. Further, DLS exhibits the average size of 25.2 nm and the zeta values were measured (-27.1 mV) which proves the stability of the AgNPs. The conversion of Ag(+) ions into Ag(0) was calculated using inductively coupled plasma atomic emission spectroscopy (ICP-MS) and was found to be 96 %. The biosynthesized AgNPs showed the larvicidal activity with the LC50 values of 17.24 and 13.12 mg/L against the fourth-instar larvae of Anopheles subpictus and Culex quinquefasciatus, respectively. The GC-MS analysis of the plant extract showed that 39 bioactive phytochemical compounds have been found to possess a wide range of activities, which may help in the protection against incurable diseases.


Assuntos
Inseticidas/farmacologia , Nanopartículas Metálicas , Prata , Violaceae/química , Animais , Anopheles , Culex , Cromatografia Gasosa-Espectrometria de Massas , Inseticidas/análise , Larva/efeitos dos fármacos , Nanopartículas Metálicas/química , Extratos Vegetais/química , Folhas de Planta/química , Prata/química , Temperatura , Difração de Raios X
18.
ACS Chem Biol ; 10(11): 2491-500, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26322745

RESUMO

Cyclotides are macrocyclic proteins produced by plants for host defense. Although they occur sparsely in other plant families, cyclotides have been detected in every Violaceae plant species so far screened. Many of the Violaceae species examined until now have been from closely related geographical regions or habitats. To test the hypothesis that cyclotides are ubiquitous in this family, two geographically isolated (and critically endangered) species of Australasian Violaceae, namely Melicytus chathamicus and M. latifolius, were examined. Surprisingly, we discovered a suite of cyclotides possessing novel sequence features, including a lysine-rich nature, distinguishing them from "conventional" cyclotides and suggesting that they might have different physiological activities in plants to those reported to date. The newly discovered cyclotides were found to bind to lipid membranes and were cytotoxic against cancer cell lines but had low toxicity against red blood cells, which is advantageous for potential therapeutic applications. This suite of novel Lys-rich cyclotides emphasizes the broad diversity of cyclotides in Violaceae species.


Assuntos
Ciclotídeos/química , Lisina/química , Violaceae/química , Sequência de Aminoácidos , Células Cultivadas , Ciclotídeos/farmacologia , Motivos Nó de Cisteína , Eritrócitos/efeitos dos fármacos , Humanos , Lisina/farmacologia , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Peptídeos/química , Peptídeos/genética , Ligação Proteica , Espectrometria de Massas por Ionização por Electrospray
20.
Chin J Nat Med ; 11(3): 199-206, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23725830

RESUMO

Hybanthus enneaspermus (L.) F. Muell belonging to the family Violaceae, popularly known as Ratanpurus (Hindi) is a herb or a shrub distributed in the tropical and subtropical regions of the world. In the Ayurvedic literature, the plant is reported to cure conditions of "Kapha" and "Pitta", urinary calculi, strangury, painful dysentery, vomiting, burning sensation, wandering of the mind, urethral discharge, blood trouble, asthma, epilepsy, cough, and to give tone to the breasts. Phytochemically, the plant contains a considerable amount of dipeptide alkaloids, aurantiamide acetate, isoarborinol, and ß-sitosterol, sugars, flavonoids, steroids, triterpenes, phenols, flavones, catachins, tannins, anthraquinones and amino acids. Pharmacologically, the plant is reported to possess antidiabetic, antiplasmodial, antimicrobial, anticonvulsant, nephroprotective, aphrodisiac, hepatoprotective, antiinflammatory, aldose reductase inhibitory and free radical scavenging activities. The information provided in this review will be worthwhile to know the applicability of H. enneaspermus for the treatment of various acute or chronic diseases with a diverse nature of phytoconstituents. The overall data in this review article were collected from various scientific sources on the research of H. enneaspermus.


Assuntos
Extratos Vegetais/química , Extratos Vegetais/farmacologia , Violaceae/química , Animais , Humanos , Fitoterapia
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