RESUMO
Sixty-seven crude ethanol extracts from 50 plants (31 families), which are used in North Côte-d'Ivoire as traditional remedies for bacterial diseases, were screened for in vitro activity against Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus subtilis) bacteria. Thirty-one extracts showed antibacterial activity only on Gram positive bacteria. Of these, 10 extracts from 10 plant species had a promising level of activity against bacteria including strains resistant to antibiotics such as aminosides, penicillin M, macrolides, lincosamide and streptrogramin B. The most active was Erythrina senegalensis DC (Fabaceae) followed by Bobgunnia madagascariensis (Desv.) J.H. Kirkbr. & Wiersema (Caesalpinaceae), Waltheria lanceolata R. Br. ex Mast. (Sterculiaceae), Uapaca togoensis Pax. (Euphorbiaceae), Ximenia americana L. (Olacaceae), Khaya senegalensis (Ders.) A. Juss. (Meliaceae), Lannea acida A. Rich. (Anacardiaceae), Cissus populnea Guill. & Perr. (Vitaceae), Keetia hispida (Benth.) Bridson (Rubiaceae) and Ficus thonningii (Miq.) A. Rich. (Moraceae). This is the first report of the antibacterial potency of these 10 plant species on a range of bacteria. The results provided evidence that some of the studied plants might indeed be potential sources of new antibacterial agents, also against some antibiotic-resistant strains.
Assuntos
Antibacterianos/farmacologia , Medicinas Tradicionais Africanas , Plantas Medicinais , Antibacterianos/isolamento & purificação , Côte d'Ivoire , Avaliação Pré-Clínica de Medicamentos/métodos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Estruturas VegetaisRESUMO
Thirty-five crude extracts from 11 Panamanian plants, distributed in 10 genera and five families, were evaluated for their in vitro cytotoxicity. Four extracts exhibited an inhibition of cellular growth at IC(50) values lower than 25 microg/ml which was considered a significant activity.
Assuntos
Antineoplásicos/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Plantas Medicinais , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Humanos , Concentração Inibidora 50 , Neoplasias Pulmonares/tratamento farmacológico , Medicina Tradicional , Panamá , Componentes Aéreos da Planta , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Caules de Planta , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
OBJECTIVE: In the oligoarticular subgroup of juvenile idiopathic arthritis, a strong association has been found with the expression of human leukocyte antigen class II molecules HLA-DQA1 *0401-DQB1*0402 and DQA1*0501-DQB1*0301, whereas DQA1*0501-DQB1*0201 is neutral and DQA1 *0201-DQB1*0201 protective. A presentation of different peptides by these DQ alleles would support their role in the disease process. METHODS: Using a synthetic nonapeptide library, a peptide binding motif was determined for the associated DQA1*0501-DQB1*0301 molecule and compared to the neutral and the protective DQ molecules. RESULTS: A differential motif for the three molecules could be deduced, suggesting that peptides preferentially binding to the associated vs. the neutral/protective DQ-molecules are mutually exclusive. CONCLUSION: These results imply a role for differential peptide presentation in the pathogenesis of oligoarthritic JIA. The search for peptides initiating the disease process might be facilitated which could then lead to therapeutical interventions.
Assuntos
Artrite Juvenil/metabolismo , Antígenos HLA-DQ/imunologia , Biblioteca de Peptídeos , Peptídeos/metabolismo , Artrite Juvenil/imunologia , Artrite Juvenil/fisiopatologia , Humanos , Peptídeos/imunologiaRESUMO
A total of 148 crude ethanol extracts from 115 plant species were tested in vitro against Gram-negative strains (Escherichia coli, Pseudomonas aeruginosa) and the Gram-positive Staphylococcus aureus and Enterococcus faecalis. Moreover, they were submitted to antifungal assays against Candida albicans and Cladosporium cucumerinum, a human and a plant pathogenic microorganism, respectively, known to be good indicators of antifungal activity. No activity was detected against the Gram-negative bacteria, while 14.8% and 10.8% of the extracts showed Gram-positive bactericidal or bacteriostatic effects on S. aureus and E. faecalis, respectively. An antifungal activity was observed with 15 extracts (10.1%). Two species were particularly active against the fungi: Dioscorea minutiflora and Erythrina vogelii. The young tubers of D. minutiflora contain metabolites with a specific effect on fungi and were not active against the bacteria. On the other hand, E. vogelii was highly effective against the Gram-positive bacteria and the fungi.
Assuntos
Anti-Infecciosos/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Antibacterianos , Bactérias/efeitos dos fármacos , Côte d'Ivoire , Fungos/efeitos dos fármacos , Testes de Sensibilidade MicrobianaRESUMO
Phytochemical investigation of the CH2Cl2 extract of Erythrina vogelii led to the isolation of five isoflavonoids. Three prenylated isoflavonoids are new natural compounds. The isolation of the antifungal compounds was monitored by inhibition of the growth of Cladosporium cucumerinum in a direct TLC bioautographic assay. The structures of these compounds were elucidated by spectroscopic techniques.
Assuntos
Antifúngicos/farmacologia , Cladosporium/efeitos dos fármacos , Erythrina , Flavonoides/isolamento & purificação , Isoflavonas/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Flavonoides/química , Flavonoides/farmacologia , Isoflavonas/química , Isoflavonas/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Prenilação de ProteínaRESUMO
Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.
Assuntos
Cromatografia Líquida/métodos , Ilex paraguariensis/química , Espectroscopia de Ressonância Magnética/métodos , Ácido Oleanólico/análogos & derivados , Saponinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Sequência de Bases , Isótopos de Carbono , Hidrólise , Dados de Sequência Molecular , Saponinas/análise , Saponinas/isolamento & purificaçãoRESUMO
The terpenoid constituents of Targionia lorbeeriana grown in vivo and in vitro were compared. The analysis of the dichloromethane extract was performed by HPLC-UV and by HPLC-MS. The obtained results revealed that the sesquiterpene lactones isolated from the dichloromethane extract of the wild Targionia lorbeeriana were also produced by the liverwort in in vitro cultures, in the same relative amounts. The composition of essential oils was evaluated by GC and GC-MS. Both, the yield and diversity of the essential oil obtained from wild growing T. lorbeeriana gametophytes were higher than those growing in vitro. Although, a significant number of compounds produced in vivo were maintained in vitro, a considerable number of other ones were not detected. Instead, under in vitro conditions, some new compounds were found which do not accumulate under wild conditions.
Assuntos
Lactonas/química , Magnoliopsida/química , Óleos Voláteis/química , Sesquiterpenos/química , Células Cultivadas , Cromatografia Líquida de Alta Pressão/métodos , Meio Ambiente , Cromatografia Gasosa-Espectrometria de Massas , Lactonas/isolamento & purificação , Magnoliopsida/crescimento & desenvolvimento , Espectrometria de Massas/métodos , Óleos Voláteis/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Terpenos/química , Terpenos/isolamento & purificação , Raios UltravioletaRESUMO
A total of 78 different extracts from 20 medicinal plants belonging to 14 plant families from Mali were tested for their antifungal, larvicidal, molluscicidal, antioxidant and radical scavenging activities. Dichloromethane, methanol, water and ethanol extracts were used. TLC autobiography for antifungal activity was run with Cladosporium cucumerinum and Candida albicans. Extracts were also tested on the larvae of the mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Molluscicidal activities were established with the snails Biomphalaria glabrata, Biomphalaria pfeifferi and Bulinus truncatus. beta-Carotene and DPPH solutions sprayed on TLC plates were used for antioxidant and radical scavenging assays. Of the extracts investigated, 20% were antioxidant and radical scavengers, 19% fungicidal, 30% were larvicidal and 11% were molluscicidal. Three of the plant extracts, from Cussonia barteri (Araliaceae), Glinus oppositifolius (Aïzoaceae) and Lannea velutina (Anacardiaceae) gave positive responses in all four tests.
Assuntos
Antifúngicos/farmacologia , Inseticidas/farmacologia , Moluscocidas/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais , Aedes/efeitos dos fármacos , Animais , Anopheles/efeitos dos fármacos , Antioxidantes/farmacologia , Biomphalaria/efeitos dos fármacos , Bulinus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Cladosporium/efeitos dos fármacos , Culex/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Humanos , Larva/efeitos dos fármacos , Mali , Medicinas Tradicionais Africanas , Testes de Sensibilidade MicrobianaRESUMO
In order to discover new bioactive compounds from plant sources which could become new leads or new drugs, extracts should be simultaneously evaluated by chemical screening and by various biological or pharmacological targets. Chemical screening using hyphenated techniques such as LC/UV and LC/MS, and more recently LC/NMR, quickly provides ample structural information, leading in many cases to the identification of compounds. This allows researchers to distinguish between known compounds (dereplication) and new molecules directly from crude plant extracts. Thus, the tedious isolation of known compounds can be avoided, and a targeted isolation of constituents presenting novel or unusual spectroscopic features can be undertaken. In parallel, extracts are also subjected to various bioassays that should be simple, reproducible, and rapid. This approach will be illustrated by the search for new molluscicidal, antioxidant, and antifungal compounds from tropical plants.
RESUMO
Six compounds have been isolated from the methanol extract of the aerial parts of Gnidia involucrata (Thymelaeaceae). They were identified as 2,3,4',5,6-pentahydroxybenzophenone-4-C-glucoside and 2,4',6-trihydroxy-4-methoxybenzophenone-2-O-glucoside, together with mangiferin, kaempferol-3-O-glucoside, yuankanin and manniflavanone by chemical and spectroscopic means. The structures of three additional C-glycosyl flavones--vitexin, isovitexin and isoorientin--were determined on-line by LC/UV/APCI-MSn analysis of the crude extract.
Assuntos
Aracnídeos/química , Benzofenonas/química , Glicosídeos/isolamento & purificação , Animais , Glicosídeos/química , Estrutura Molecular , Análise EspectralRESUMO
Two new cyclobutane-type lignans, named moslolignans A and B, together with two known ones, andamanicin and magnosalin, were isolated from the whole plant of Mosla scabra. Their structures were established as 1beta*,2beta*,3alpha*,4alpha*-1,2-dimethyl-3-(3- methoxy-4,5-methylene-dioxyphenyl)-4-(2,4,5-trimethoxyphenyl)-cycl obutane and 1beta*,2beta*,3alpha*,4alpha*-1,2-dimethyl-3-(2, 5-dimethoxy-3,4-methylenedioxyphenyl)-4-(2,4,5-trimethoxyphenyl)-cyclobu tane by spectroscopic methods. This is the first report of naturally-occurring cyclobutane-type lignans with asymmetrical substitutions.
Assuntos
Alcenos/isolamento & purificação , Ciclobutanos/isolamento & purificação , Plantas Medicinais/química , Ciclobutanos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrofotometria UltravioletaRESUMO
Rapid detection of biologically active natural products plays a key role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Techniques such as HPLC coupled to UV photodiode array detection (LC/DAD-UV) and to mass spectrometry (LC/MS or LC/MS/MS) provide numerous on-line structural data on the metabolites prior to isolation. The recent introduction of HPLC coupled to nuclear magnetic resonance (LC/NMR) represents a powerful complement to LC/UV/MS screening. Various plant species belonging to the Gentianaceae and Leguminosae have been analysed by LC/UV, LC/MS, LC/MS/MS and LC/NMR. These hyphenated techniques allow a rapid structural determination of known plant constituents with only a minute amount of plant material. Simple bioautographic assays such as those used for screening antifungal constituents can also be performed on-line directly by collecting HPLC peaks and measuring the activity against the fungi of interest. These bioassays permit a rapid localisation of the bioactive natural products. With such a combined approach, the time consuming isolation of common natural products is avoided and an efficient targeted isolation of compounds presenting interesting spectroscopical or biological features is performed. Several representative applications of the use of LC/MS and LC/NMR for the dereplication and identification of antifungal constituents are presented in the present paper.
RESUMO
The leaves and bark dichloromethane extracts of Ravensara anisata showed antifungal activity against the yeast Candida albicans and the phytopathogenic fungus Cladosporium cucumerinum in bioautographic TLC assays. Activity-guided fractionation afforded two new alpha-pyrones: 6R*-(4R*-acetoxy-2S*-hydroxy- 8-phenyloctyl)-5,6-dihydro-2-H-pyran-2-one and 6R*-(2S*-acetoxy-4R*- hydroxy-8-phenyloctyl)-5,6-dihydro-2-H-pyran-2-one. Their structures have been established by NMR spectroscopy, chemical methods and X-ray crystallographic analysis. The antifungal activity against C. albicans and C. cucumerinum was determined for both compounds.
Assuntos
Plantas Medicinais/química , Pironas/química , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Cromatografia em Gel , Cristalografia por Raios X , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Pironas/isolamento & purificação , Pironas/farmacologia , Análise EspectralRESUMO
A new antifungal and radical scavenging 2-hydroxyflavanone, named mosloflavanone, was isolated from the dichloromethane extract of Mosla soochouensis together with the known mosloflavone and moslosooflavone. Structures were established by spectroscopic and chemical methods, as well as X-ray crystallography.
RESUMO
Presentation of antigenic gliadin peptides by the HLA-DQ2 molecule is considered as a key event in celiac disease pathogenesis. Chemical deamidation of the side chains of glutamine residues might have a strong influence on gliadin peptide binding to the DQ2 molecule. Glutamine deamidation of A-gliadin peptide (45-56) under acidic conditions corresponding to the gastric environment was studied using RP-HPLC, Edman degradation, capillary electrophoresis and electrospray mass spectrometry. Deamidation resulted in peptides with increased DQ2-affinities as assessed in a cell-free binding assay.