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2.
An Acad Bras Cienc ; 91(3): e20180404, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365649

RESUMO

In this study, the antimicrobial, antioxidant and antitumor activity of ethanol extracts obtained from Phlomis russeliana (Sims.) Lag. ex Benth. (Lamiaceae) were evaluated. Disc diffusion and microdilution methods were used to test the extracts for antimicrobial activity against seven bacteria strains (Bacillus cereus ATCC 7064, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538P, Escherichia coli ATCC 10538, Proteus vulgaris ATCC 6899, Salmonella typhimurium CCM 5445 and Pseudomonas aeruginosa ATCC 27853) and four yeast strains (Kluyveromyces fragilis ATCC 8608, Rhodotorula rubra ATCC 70403, Debaryomyces hansenii DSM 70238 and Candida albicans ATCC 10239). Notably, they were more effective against the yeast strains than the bacterial strains. Of the yeast cultures, D. hanseii was among the most susceptible, having an inhibition zone of 16.2 mm with minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of 64(128)µg/ml, respectively. For cytotoxic determination, Caco-2 cells were cultured as per ATCC protocol, and were treated with log concentrations (5-80 mg/ml) of P. russeliana. The potency of cell growth inhibition for each extract was expressed as an IC50 value. Moreover, oxidant capacity was evaluated via TOC assay. This product induced antiproliferative activity of 31.33% at 40 mg/ml and 20.96% at 80 mg/ml, without toxic effects on cells, although the oxidant capacity was decreased to 27.06 ± 0.7 nm in the 80 mg/ml-applied group compared to 47.9 ± 1.8 nm in the untreated one. Advanced pharmacological studies are needed to further evaluate P. russeliana for distinctive features.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Candida albicans/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Phlomis/química , Extratos Vegetais/farmacologia , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Células CACO-2 , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificação , Humanos , Turquia
3.
J Med Microbiol ; 68(9): 1359-1366, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31364964

RESUMO

Methodology. Biochemical and molecular methods were used to identify 100 lactobacilli isolated from rectal swabs. Among these, L. paracasei ssp. paracasei LP5 and L. brevis LP9 showed significant antibacterial activity against S. agalactiae and L. monocytogenes. Accordingly, characterization of their bacteriocins, BacLP5 and BacLP9, was conducted to obtain information on their kinetic production, sensitivity to chemico-physical parameters and molecular weight. To investigate the possible use of the two Lactobacillus strains as probiotics, their gastrointestinal resistance, cellular adhesiveness and sensitivity to antibiotics were also studied.Results. The obtained data show that BacLP5 and BacLP9 most likely belong to class II bacteriocins and both have a molecular weight of approximately 3 kDa. The production of BacLP5 and BacLP9 started after 4 h (40 and 80 AU ml-1), respectively. Both of the Lactobacillus strains survived gastric and intestinal juices well and showed adhesive capability on HEp-2 cells.Conclusion. Due to their peculiar antimicrobial characteristics, L. paracasei ssp. paracasei LP5 and L. brevis LP9 are suitable for use in the treatment of vaginal disorders, through both oral and transvaginal administration.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Lactobacillus brevis/metabolismo , Lactobacillus paracasei/metabolismo , Antibacterianos/química , Antibacterianos/isolamento & purificação , Aderência Bacteriana , Bacteriocinas/química , Bacteriocinas/isolamento & purificação , Ácidos e Sais Biliares/farmacologia , Linhagem Celular , Fenômenos Químicos , Suco Gástrico/metabolismo , Humanos , Lactobacillus brevis/classificação , Lactobacillus brevis/isolamento & purificação , Lactobacillus paracasei/classificação , Lactobacillus paracasei/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Peso Molecular , Probióticos , Reto/microbiologia , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/crescimento & desenvolvimento
4.
J Agric Food Chem ; 67(32): 9088-9095, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31347836

RESUMO

Triclocarban (TCC) and triclosan (TCS) have been simultaneously detected in five kinds of foodstuffs using an immunoaffinity purification method coupled with ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the first time. Two highly specific monoclonal antibodies against TCC and TCS were produced and coupled to N-hydroxysuccinimide-activated Sepharose 6B gel to prepare the immunosorbent. Under the optimal conditions, mean recoveries from spiked samples by the IAC-UHPLC-MS/MS method were 70.1-92.8% for TCC and 76.6-102.5% for TCS. Intraday relative standard deviations were below 14.5%. The limits of quantification (LOQs) of TCC were 1 ng/L for beverage samples and 0.01-0.02 µg/kg for food samples. The LOQs of TCS were 0.03 µg/L for beverage samples and 0.2-0.3 µg/kg for food samples. The applicability of the method has been proven by analyzing TCC and TCS in different samples from supermarkets in Beijing. The proposed method is sufficiently sensitive and reliable for monitoring trace concentrations of TCC and TCS in food samples.


Assuntos
Antibacterianos/análise , Carbanilidas/análise , Cromatografia de Afinidade/métodos , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Triclosan/análise , Antibacterianos/isolamento & purificação , Bebidas/análise , Carbanilidas/isolamento & purificação , Contaminação de Alimentos/análise , Técnicas de Imunoadsorção , Triclosan/isolamento & purificação
5.
Fitoterapia ; 137: 104254, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31271782

RESUMO

Five new polyphenolic derivatives, sepiumols A-E (1-5), were isolated from the root barks of Periploca sepium. Their structures were elucidated by interpretation of NMR spectroscopic and mass spectrometric data. Compounds 1, 3 and 5 were found to exhibit significant antifungal activity, particularly for 3 with the remarkable activity against Gibberella saubinetii and Alternaria longipes with MIC values of 1.56 and 3.13 µg/mL (ketoconazole: 0.78 µg/mL), respectively. In addition, compounds 1, 3 and 5 also displayed significant antibacterial activity against methicillin-resistant Staphylococcus aureu with MIC values of 12.50-25 µg/mL (ciprofloxacin: 0.78 µg/mL).


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Periploca/química , Polifenóis/farmacologia , Alternaria/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Gibberella/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Casca de Planta/química , Raízes de Plantas/química , Polifenóis/isolamento & purificação
6.
Fitoterapia ; 137: 104257, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31278976

RESUMO

Two new meroditerpene pyrones, chevalone F (1) and 11-hydroxychevalone E (2), a new tryptoquivaline analog, tryptoquivaline V (3) and a new brasiliamide analog, brasiliamide G (4), together with thirteen known compounds, chevalones A-C (5-7), chevalone E (8), 11-hydroxychevalone C (9), pyripyropene A (10), isochaetominine C (11), pyrrolobenzoxazine terpenoids CJ-12662 (12) and CJ-12663 (13), fischerindoline (14), eurochevalierine (15), 1,4-diacetyl-2,5-dibenzylpiperazine-3,7''-oxide (16) and lecanorin (17) were isolated from the fungus Neosartorya pseudofischeri. Their structures were established on the basis of spectroscopic evidence. Compound 2 showed weak antibacterial activity against Escherichia coli and Salmonella enterica serovar Typhimurium, whereas compounds 7, 12, 13 and 15 showed antibacterial activity against Bacillus cereus and Staphylococcus aureus. In addition, compounds 13 and 14 showed cytotoxicity against KB and MCF-7 cancer cell lines, as well as the Vero cell line.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Indóis/farmacologia , Neosartorya/química , Pironas/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Cercopithecus aethiops , Florestas , Humanos , Indóis/isolamento & purificação , Células KB , Células MCF-7 , Estrutura Molecular , Pironas/isolamento & purificação , Microbiologia do Solo , Tailândia , Células Vero
7.
Plant Foods Hum Nutr ; 74(3): 364-369, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31214936

RESUMO

This study aimed to optimize the extraction conditions for Sorbus umbellata (Desf.) Fritsch var. umbellata leaves to maximize the phenolic content and their antioxidant activity and to investigate ß-glucuronidase (GUS) enzyme inhibitory, antimicrobial and cytotoxic potentials of the extracts obtained under optimum conditions. The optimum extraction conditions were found to be 78.2 and 79.7% solvent, 73.1 and 71.5 °C, and 89.9 and 88.8 min to maximize phenolic content and antioxidant activity, respectively. Low values of coefficient of variations indicate the high reliability and reproducibility of the conducted extraction experiments. Bioactivity results showed that extracts had cytotoxic effect on the MCF-7 and A549 cells where the highest cell proliferation inhibition was observed for the A549 cell line (71.8% at 150 µg/mL). Staphylococcus aureus showed highest zone of inhibition (19.3 mm) in all bacteria followed by Escherichia coli. Additionally, extracts displayed potential GUS inhibitory activity. In conclusion, Sorbus umbellata leaf extract can be obtained by optimized cost-saving extraction and has a potential bioactivity to be utilized as a food ingredient for high value-added products and/or nutraceuticals development where it can combat oxidative stress and GUS mediated reactive metabolite formation.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Fenóis/análise , Extratos Vegetais/farmacologia , Sorbus/química , Células A549 , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Escherichia coli/efeitos dos fármacos , Glucuronidase/antagonistas & inibidores , Humanos , Células MCF-7 , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Reprodutibilidade dos Testes , Staphylococcus aureus/efeitos dos fármacos
8.
Phytochemistry ; 165: 112048, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31229789

RESUMO

For the first time, the pigment composition of basidiocarps from the Chilean mushroom Cortinarius pyromyxa was studied under various aspects like phylogeny, chemistry and antibiotic activity. A molecular biological study supports the monotypic position of C. pyromyxa in subgenus Myxacium, genus Cortinarius. Four undescribed diterpenoids, named pyromyxones A-D, were isolated from fruiting bodies of C. pyromyxa. Their chemical structures were elucidated based on comprehensive one- and two-dimensional NMR spectroscopic analysis, ESI-HRMS measurements, as well as X-ray crystallography. In addition, the absolute configurations of pyromyxones A-D were established with the aid of JH,H, NOESY spectra and quantum chemical CD calculation. The pyromyxones A-D possess the undescribed nor-guanacastane skeleton. Tested pyromyxones A, B, and D exhibit only weak activity against gram-positive Bacillus subtilis and gram-negative Aliivibrio fischeri as well as the phytopathogenic fungi Botrytis cinerea, Septoria tritici and Phytophthora infestans.


Assuntos
Antibacterianos/farmacologia , Cortinarius/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Pigmentos Biológicos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Cristalografia por Raios X , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Filogenia , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificação , Teoria Quântica
9.
Phytochemistry ; 164: 192-205, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31174083

RESUMO

The chemical composition of five marine microalgae (Dunaliella sp., Dunaliella salina, Chaetoceros calcitrans, Chaetoceros gracilis and Tisochrysis lutea) was investigated through nuclear magnetic resonance (NMR) spectroscopic study of the soluble material obtained by sequential extraction with hexane, ethyl acetate (AcOEt) and methanol of biomass from stationary phase cultures. Hexane extracted the major lipids present in the microalgae during the stationary phase of growth, which correspond to storage lipids. Triacylglycerols (TGs) were the only storage lipids produced by Dunaliella and Chaetoceros. In contrast, T. lutea predominantly stored polyunsaturated long-chain alkenones, with sterols also detected as minor components of the hexane extract. The molecular structure of brassicasterol was determined in T. lutea and the presence of squalene in this sample was also unequivocally detected. Monogalactosyldiacylglycerols (MGDGs) and pigments were concentrated in the AcOEt extracts. C. calcitrans and D. salina constituted an exception due to the high amount of TGs and glycerol produced, respectively, by these two strains. Chlorophylls a and b and ß-carotene were the major pigments synthesized by Dunaliella and chlorophyll a and fucoxanthin were the only pigments detected in Chaetoceros and T. lutea. Information concerning the acyl chains present in TGs and MGDGs as well as the positional distribution of acyl chains on the glycerol moiety was obtained by NMR analysis of hexane and AcOEt extracts, with results consistent with those expected for the genera studied. Fatty acid composition of TGs in the two Dunaliella strains was different, with polyunsaturated acyl chains almost absent in the storage lipids produced by D. salina. Except in C. calcitrans, the polar nature of soluble compounds was inferred through the relative extraction yield using methanol as the extraction solvent. Glycerol was the major component of this fraction for the Dunaliella strains. In T. lutea 1,4/2,5-cyclohexanetetrol (CHT) and dimethylsulfoniopropionate (DMSP) preponderated. CHT was also the major polyol present in the Chaetoceros strains in which DMSP was not detected, but prominent signals of 2,3-dihydroxypropane-1-sulfonate (DHSP) were observed in the 1H NMR spectra of methanolic extracts. The presence of DHSP confirms the production of this metabolite by diatoms. In addition, several other minor compounds (digalactosyldiacyglycerols (DGDGs), sulphoquinovosyldiacylglycerols (SQDGs), amino acids, carbohydrates, scyllo-inositol, mannitol, lactic acid and homarine) were also identified in the methanolic extracts. The antibacterial and antibiofilm activities of the extracts were tested. The AcOEt extract from C. gracilis showed a moderate antibiofilm activity.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Microalgas/química , Ressonância Magnética Nuclear Biomolecular , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Microalgas/metabolismo , Testes de Sensibilidade Microbiana , Conformação Molecular
10.
J Microbiol Biotechnol ; 29(7): 1033-1042, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31216789

RESUMO

Bacillus velezensis BS2 was isolated from meongge (common sea squirt) jeotgal, a Korean fermented seafood, and produces a bacteriocin, BacBS2, which strongly inhibits Listeria monocytogenes and Bacillus cereus. BacBS2 was partially purified by Q-Sepharose column chromatography after ammonium sulfate precipitation of the culture supernatant, then further purified by Sephadex G-50 column chromatography. Partially purified BacBS2 was estimated to be 6.5 kDa in size by Tricine-SDS PAGE and activity detection by gel-overlay. Enzyme treatment and FT-IR spectrum of partially purified BacBS2 confirmed its proteinaceous nature. BacBS2 was fully stable at pH 4-9, and half of activity was retained at pH 1-3. Full activity was retained after exposure to 80°C for 15 min, but half of the activity was retained upon exposure to 90°C for 15 min or 100°C for 10 min. BacBS2 inhibited L. monocytogenes by bactericidal mode of action. B. velezensis BS2 and its BacBS2 seem useful as biopreservatives for fermented foods such as jeotgal.


Assuntos
Antibacterianos/metabolismo , Bacillus/metabolismo , Bacteriocinas/isolamento & purificação , Bacteriocinas/metabolismo , Alimentos Fermentados/microbiologia , Conservantes de Alimentos/metabolismo , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antibiose , Bacillus/crescimento & desenvolvimento , Bacillus/fisiologia , Bacillus cereus/efeitos dos fármacos , Bacteriocinas/química , Bacteriocinas/farmacologia , Meios de Cultura , Conservantes de Alimentos/química , Conservantes de Alimentos/isolamento & purificação , Conservantes de Alimentos/farmacologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Listeria monocytogenes/efeitos dos fármacos , Peso Molecular , Estabilidade Proteica
11.
BMC Complement Altern Med ; 19(1): 120, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170979

RESUMO

BACKGROUND: Albizia adianthifolia (Schum.) is medicinally used in Cameroon to manage bronchitis and skin diseases. Our previous study documented the antibacterial potential of its roots' methanol extract. In this study, methanol roots extract was subjected to chromatography techniques and fractions (AARa and AARb), sub-fractions (AARa1-4, AARb1-2 and AARb11-14) together with isolated phytochemicals were assessed for their antimicrobial as well as their antibiotic-potentiating effects towards Gram-negative multidrug resistant (MDR) bacteria. METHODS: The antibacterial activities of the samples (determination of Minimal Inhibitory « MIC ¼ and Minimal Bactericidal Concentration « MBC ¼) were determined by the modified rapid p-iodonitrotetrazolium chloride (INT) colorimetric assay, as well as those of antibiotics in association with the compounds. Column chromatography was applied to isolate phytochemicals from roots extract and their chemical structures were determined using spectroscopic techniques. RESULTS: The phytochemicals isolated were stearic acid (1), a mixture (1:1) of stigmasterol and ß-sitosterol (2 +  3), ß-sitosterol 3-O-ß-D-glucopyranoside (4), palmatin (5), homomangiferin (6) and mangiferin (7). Fraction AARa exhibited selective inhibitory effects whilst all tested bacteria were inhibited by AARb in MIC ranges of 8 to 1024 µg/mL. Sub-fractions AARb1-2 had MIC values between 8 µg/mL and 1024 µg/mL on all tested bacteria. Phytochemicals 4, 2 +  3 and 7 inhibited the growth of 54.54% (6/11), 45.45% (5/11) and 27.27% (3/11) tested bacterial strains, respectively. When tested with an efflux pumps inhibitor (Phenylalanine-Arginine-ß-Naphthylamide or PAßN), the inhibitory effects of compounds 2 + 3 and 4 increased towards all the tested bacteria. In association with erythromycin (ERY), streptomycin (STR) and tetracycline (TET), compounds 2 + 3 and 4 had the most significant synergistic activity on the seven selected bacteria. CONCLUSION: The present study provides information on the possible use of Albizia adianthifolia and its constituents in the control of Gram-negative infections including MDR phenotypes.


Assuntos
Albizzia/química , Antibacterianos/isolamento & purificação , Sinergismo Farmacológico , Compostos Fitoquímicos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/farmacologia
12.
J Agric Food Chem ; 67(26): 7297-7303, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244198

RESUMO

3,6-Anhydro-l-galactose (AHG) produced from agarose in red macroalgae was recently suggested as an anticariogenic sugar to replace widely used xylitol. However, the multi-step process for obtaining monomeric sugar AHG from agarose may be expensive. Generally, it is easier to obtain oligosaccharides than monosaccharides from polysaccharides. Therefore, a one-step process to obtain agarobiose (AB) from agarose was recently developed, and here, we suggest AB as a new anticariogenic agent, owing to its anticariogenic activity against Streptococcus mutans. Among AHG-containing oligosaccharides, AB, neoagarobiose (NAB), agarooligosaccharides (AOSs), and neoagarooligosaccharides (NAOSs), AB showed higher inhibitory activity than AOSs against the growth and lactic acid production of S. mutans; no such inhibitory activity was observed for NAB and NAOSs. This inhibitory effect of AB was comparable to the previously reported inhibitory activity of AHG against S. mutans. These results suggest that AB, which can be more economically and simply produced than AHG, may serve as an anticariogenic sugar.


Assuntos
Antibacterianos/farmacologia , Dissacarídeos/farmacologia , Oligossacarídeos/farmacologia , Extratos Vegetais/farmacologia , Rodófitas/química , Alga Marinha/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Dissacarídeos/química , Dissacarídeos/isolamento & purificação , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento
13.
Bioresour Technol ; 289: 121683, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31238291

RESUMO

This study examined the removal of varying concentrations of the antibiotic Ciprofloxacin (CIP) over the long-term (120 days) in an anaerobic membrane bioreactor (AnMBR). The results showed that 50-76% CIP was removed with 0.5-1.5 mg CIP/L in the feed, although at 4.7 mg/L its removal efficiency decreased to <20%. It was found that biological degradation was the main mechanism for removing CIP, while adsorption onto the sludge only contributed a small fraction, and an even smaller fraction was due to the waste sludge discharged. CIP was biodegraded to some degree in the AnMBR, with some intermediate compounds detected using LC-MS/MS and GC-MS. This work showed the effectiveness of an AnMBR in removing CIP at low concentrations of <1.5 mg/L, and hence may be an effective treatment for removing other antibiotics from wastewater.


Assuntos
Antibacterianos/isolamento & purificação , Reatores Biológicos , Ciprofloxacino/isolamento & purificação , Adsorção , Anaerobiose , Biodegradação Ambiental , Esgotos
14.
Fitoterapia ; 137: 104239, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201886

RESUMO

In the search for bioactive natural products from the African flora, three previously undescribed compounds including one stilbene-coumarin derivative (1), one coumarin-carbinol (2) and one fatty glycoside (3) were isolated from the stem bark and leaves of Monotes kerstingii, together with sixteen known compounds (4-19). The structures of the isolated compounds were elucidated based on their NMR and MS spectroscopic data and by comparison of these data with those previously reported in the literature. Compounds 1-19 were screened for anthelmintic and antimicrobial activity. None of the compounds exhibited significant anthelmintic activity. However, compounds 4, 5, 8 and 14 displayed interesting antibacterial activity against B. subtilis at a concentration of 100 µM with respective inhibition percentages of 99, 79, 71 and 100%, respectively, compared to erythromycin used as positive control. In addition, at the same concentration, compound 6 showed remarkable antifungal activity against Septoria tritici with 93.6% growth inhibition and was found to be more active than the positive controls epoconazole and terbinafine displaying 76.6 and 84.3%, respectively .


Assuntos
Anti-Helmínticos/farmacologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Dipterocarpaceae/química , Anti-Helmínticos/isolamento & purificação , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Camarões , Cumarínicos/isolamento & purificação , Cumarínicos/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Casca de Planta/química , Folhas de Planta/química
15.
BMC Complement Altern Med ; 19(1): 150, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31242939

RESUMO

BACKGROUND: Traditional medicine remedies are commonly used for treatment of diverse ailments including bacterial infections. The activity against resistant bacteria and safety of some remedies sold as anti-infective treatments in market places in Buea, Southwest Cameroon were investigated as potential alternative treatment to counter increasing antibiotic resistance. METHODS: Ten remedies were purchased, their components documented and microbial load estimated. Methanol extracts of the remedies were tested for antibacterial activity by disc diffusion and microdilution. Cytotoxicity was evaluated on monkey kidney epithelial cells (LLC-MK2) while acute oral toxicity was done in BALB/c mice for the bactericidal extract. Extracts were further analysed using phytochemical tests. RESULTS: All the remedies had microbial loads above the acceptable limit of 105 CFU/g. The highest activity was produced by extracts of four remedies (TP 1, 2, 4, 6a, 6b) against all clinical isolates among which three were active against four control strains. Zones of inhibition ranged from 8 to 27 mm. Two of the four extracts produced zones ≥20 mm against multidrug resistant clinical isolates of Citrobacter freundii and Escherichia coli but were less active compared to Gentamycin positive control (P < 0.0001-0.0014). The most active extracts also recorded minimum inhibitory concentrations of 1 to 4 mg/mL. One of them (TP2) was bactericidal against a clinical isolate of methicillin-resistant Staphylococcus aureus with a minimum bactericidal concentration of 8 mg/mL. Extracts of six remedies did not show cytotoxicity and no mortality or adverse effect was recorded in the acute oral toxicity test. Phytochemical screening showed the most active extracts contained relatively high amounts of alkaloids and flavonoids. CONCLUSION: Only four of the eight remedies tested showed activity against multidrug resistant bacteria suggesting some of these remedies may not be effective against bacterial infections. Production and handling methods should be improved and the product quality controlled to ensure biosecurity. The remedies which were both active and non-toxic should be further investigated including in vivo experiments to assess their efficacy.


Assuntos
Antibacterianos/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/toxicidade , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Camarões , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Feminino , Humanos , Medicina Tradicional , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Plantas Medicinais/microbiologia
16.
BMC Complement Altern Med ; 19(1): 141, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221162

RESUMO

BACKGROUND: Antimicrobial resistance (AMR) remains an important global health issue but the gap between AMR and development of new antimicrobials is increasing. Plant extracts may have good activity per se or may be sources of effective antimicrobial compounds which can act against planktonic and/or biofilms of pathogens. We determined the antimicrobial efficacy and cytotoxicity of some under-investigated plants from the Myrtaceae family endemic to South Africa. The ability of the plant extracts to inhibit or destroy pre-formed bacterial biofilms was also determined. METHODS: Based on previous preliminary in vitro screening and on chemotaxonomy, nine species from the Myrtaceae family were selected. The antimicrobial activity of the crude acetone leaf extracts was determined against six common nosocomial pathogens, namely: Gram-positive bacteria (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) using a two-fold serial microdilution assay with p-iodonitrotetrazolium violet as growth indicator. The number of antimicrobial compounds present in extracts was determined by bioautography. Cytotoxicity of extracts was determined against Vero kidney cells using a colorimetric tetrazolium-based assay. The total antibacterial activity (TAA) in ml/g and selectivity index (LC50/MIC) of the plant extracts were calculated. A modified crystal violet assay was used to determine the antibiofilm activity of the extracts. RESULTS: Syzygium legatii, Syzygium masukuense, and Syzygium species A had the best activities against Gram-negative and Gram-positive bacteria (MIC) values ranging from 0.04-0.08 mg/ml. Eugenia erythrophylla had the best MIC (0.02 mg/ml) against Bacillus cereus. Many extracts had relatively low cytotoxicity (LC50 > 20 µg/ml) leading to reasonable selectivity indices. Three leaf extracts (Syzygium masukuense, Syzygium species A, and Eugenia natalitia) were moderately cytotoxic (20 µg/ml < LC50 < 100 µg/ml). The plant extracts had a good capacity to reduce biofilm formation and good to poor potential to destroy pre-formed biofilms. CONCLUSIONS: The plant species examined in this study had varying degrees of antibacterial activity against bacterial planktonic and biofilm forms with some having good activity against both forms. Several of these selected species may be potential candidates for further investigation to isolate antimicrobial compounds and to determine the mechanism of activity.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Syzygium/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/fisiologia , Dose Letal Mediana , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , África do Sul
17.
Fitoterapia ; 137: 104243, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31226283

RESUMO

Two new sesquiterpenoids, leptosphins A (1) and B (2), and a new cyclopiane diterpene, leptosphin C (3), along with four known diterpenes (4-7) were isolated from the solid fermentation cultures of an endophytic fungus Leptosphaeria sp. XL026 isolated from the leaves of Panax notoginseng. Their structures were elucidated by extensive spectroscopic methods and single-crystal X-ray diffraction (data). Compound 1 represents the first sulfur-containing eremophilane sesquiterpene. Compounds 5 and 7 displayed medium antifungal activity against Rhizoctonia cerealis, as well as 6 against Verticillium dahliae Kleb with an MIC value of 12.5 µg/mL. Furthermore, compounds 2, 5, 6 and 7 showed medium antibacterial activity against Bacillus cereus with MIC values of 12.5-6.25 µg/mL, as well as 6 also against Pseudomonas aeruginosa with an MIC value of 12.5 µg/mL.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Ascomicetos/química , Diterpenos/farmacologia , Panax notoginseng/microbiologia , Sesquiterpenos/farmacologia , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , China , Diterpenos/isolamento & purificação , Estrutura Molecular , Folhas de Planta/microbiologia , Sesquiterpenos/isolamento & purificação
18.
Fitoterapia ; 137: 104246, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31226284

RESUMO

Chemical investigation of the mangrove endophytic fungus Cladosporium sp. SCNU-F0001 resulted in the isolation and identification of a new macrolide compound named thiocladospolide E (1) and a novel macrolide lactam named cladospamide A (2), along with the known cladospolide B (3). The structures were elucidated based on spectroscopic methods, and the absolute configurations were determined by X-ray diffraction and HPLC analysis after chemical derivatization. All compounds were tested for their antibacterial and cytotoxic activity.


Assuntos
Antibacterianos/farmacologia , Cladosporium/química , Lactamas/farmacologia , Macrolídeos/farmacologia , Rhizophoraceae/microbiologia , Antibacterianos/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Lactamas/isolamento & purificação , Macrolídeos/isolamento & purificação , Estrutura Molecular
19.
J Chromatogr A ; 1602: 124-134, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31230879

RESUMO

A highly selective and effective method was successfully developed using magnetic molecular imprinted polymers (MMIPs) as solid-phase extraction (SPE) coupled with high performance liquid chromatography-ultraviolet detector (HPLC-UV) to rapidly determine cephalexin (CFX) in complex animal-derived food. MMIPs were creatively synthesized via suspension polymerization using Fe3O4 magnetic nanoparticles as supporter, CFX as template, acrylamide (AM) as functional monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The MMIPs were characterized using X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). The binding process fitted well with pseudo-second-order model with good selectivity. Scatchard plot analysis suggested that MMIPs have two types of binding sites with the Qmax of 24.18 mg g-1 and 40.25 mg g-1, respectively. And Langmuir model proved that the recognition sites were uniformly distributed in a monolayer on the surface of MMIPs. The methodological assessment showed good applicability of MMIPs with excellent recovery (85.5%-94.0%), precision (1.2%-2.4%), and stability (intra-day 1.3%-3.6%; inter-day 2.6%-4.3%) in determining CFX content. In addition, the linearity of the calibration curve was good in the range of 0.02-5.00 mg L-1, with a sensitive detection limit of 5.00 µg kg-1. The results above suggest that the obtained MMIPs exert good performance for separation of CFX in animal-derived food, and the proposed method is suitable for the reliable determination of CFX in complex samples.


Assuntos
Cefalexina/isolamento & purificação , Magnetismo , Leite/química , Impressão Molecular/métodos , Polímeros/química , Carne Vermelha/análise , Adsorção , Animais , Antibacterianos/isolamento & purificação , Cinética , Limite de Detecção , Metacrilatos/química , Nanopartículas/química , Padrões de Referência , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Temperatura Ambiente , Difração de Raios X
20.
Ultrason Sonochem ; 55: 117-124, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31084785

RESUMO

The aim of the present investigation was the combination of ZnO nanostructures with nano-cellulose (NC) for the efficient degradation of tetracycline (TC) antibiotic under ultrasonic irradiation. The removal efficiency of 12.8% was obtained by the sole use of ultrasound (US), while the removal efficiency increased up to 70% by the US/ZnO treatment process. Due to the integration of ZnO nanostructures with NC, the removal efficiency of 87.6% was obtained within 45 min. The removal efficiency substantially decreased in the presence of tert-butyl alcohol (more than 25% reduction), indicating that radOH-mediation oxidation is responsible for the degradation of TC molecules. Peroxymonosulfate (PMS) led to the most enhancing effect on the removal of TC among percarbonate, persulfate and periodate ions. The addition of PMS caused the degradation efficiency of 96.4% within the short contact time of 15 min. The bio-toxicity examination on the basis of inhibition test conducted on activated sludge revealed diminishing the oxygen consumption inhibition percent [IOUR (%)] from 33.6 to 22.1% during the US/ZnO/NC process. Consequently, the utilization of the US/ZnO/NC process can convert TC molecules to less toxic compounds. However, longer reaction time is required for complete conversion into non-toxic substances.


Assuntos
Celulose/química , Nanocompostos/química , Tetraciclina/química , Tetraciclina/isolamento & purificação , Ondas Ultrassônicas , Óxido de Zinco/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Catálise , Oxidantes/química , Peróxidos/química , Água/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
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