scholarly journals Actividad biológica y composición química en extractos de Cucurbita ecuadorensis H.C. Cutler & Whitaker

2021 ◽  
Vol 13 (2) ◽  
pp. 92-104
Author(s):  
Jhon Castillo ◽  
Shirley Moncayo

Los metabolitos secundarios presentes en los extractos etanólicos y clorofórmicos de los frutos y hojas de Cucurbita ecuadorensis H.C. Cutler & Whitaker, una especie endémica de los bosques secos de la costa de Ecuador, fueron alcaloides, flavonoides, taninos, triterpenos, esteroles y cumarinas, mientras que las quinonas, antraquinonas y saponinas estuvieron ausentes. El mesocarpio del fruto de esta especie presentó contenidos de 9.19 ± 0.25 g de carbohidratos totales/ 100 g de peso seco, 14.90 ± 0.30 g de lípidos totales/ 100 g de peso seco y 3.39 ± 0.08 g de proteínas totales/ 100 g de peso seco, respectivamente. El mayor contenido fenólico fue para el extracto etanólico de los frutos con 20.82 ± 0.87 mg de GAE /g de extracto seco. El mayor contenido de flavonoides totales fue para el extracto etanólico de los frutos con 134.36 ± 0.34 mg de CE/ g de extracto seco. El extracto etanólico del fruto revelo la mayor capacidad antioxidante con IC50= 1.90 mg/mL. Todos los extractos evaluados de esta especie, no presentaron actividad antibacteriana contra Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus subtilis subsp. spizizenii y Listeria monocytogenes. En base a estos resultados, los frutos de C. ecuadorensis se los puede considerar como un suplemento nutricional con un potencial antioxidante natural.

2019 ◽  
Vol 13 (1) ◽  
pp. 31-38
Author(s):  
Viviana Valdez ◽  
Shirley Moncayo ◽  
Xavier Cornejo ◽  
Jhon Castillo

En el presente trabajo se realizó el tamizaje fitoquímico, cuantificación de flavonoides y fenoles totales y la evaluación de la actividad antioxidante y antibacteriana de los extractos etanólicos obtenidos de hojas de Hibiscus escobariae, Loxopterygium huasango y Croton ferrugineus, contra tres bacterias Gram Positivas (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes) y tres Gram negativas (Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus). Para el análisis de las muestras se realizó el tamizaje fitoquímico por el método de Domínguez, la cuantificación de flavonoides por el método colorimétrico cloruro de aluminio, la cuantificación de fenoles totales por el método Folin-Ciocalteu, actividad antibacteriana por ensayos de difusión por disco y actividad antioxidante mediante la técnica DPPH. En el tamizaje fitoquímico los flavonoides y taninos se presentaron en mayor cantidad, mientras que los alcaloides, quinonas, antraquinonas, esteroides y saponinas estuvieron presentes en menor proporción. El contenido de flavonoides varió de 100,95 ± 1,73 a 995,42 ± 3,16 mg CE / g extracto en H. escobariae y L. huasango y el contenido de fenoles varió de 10,17 ± 0,22 a 314,72 ± 1,91 mg GAE/ g extracto en Croton ferrugineus y L. huasango que también obtuvo la mejor actividad antibacteriana frente a las cepas evaluadas con CMI que varían de 2.5 a 5 mg/mL y la mejor actividad antioxidante con IC50 de 0,1 mg/m y de 0,7 mg/mL para Croton ferrugineus con una diferencia significativa p<0.05. Estos resultados son los primeros reportados los que servirán como línea base para estudios posteriores.


2003 ◽  
Vol 58 (11-12) ◽  
pp. 850-854 ◽  
Author(s):  
Ayşen Özdemir Türk ◽  
Meral Yılmaz ◽  
Merih Kıvanç ◽  
Hayrettin Türk

Abstract In this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen Cetraria aculeata has been investigated. The extracts were tested against twelve bacteria and eight fungi and found active against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Proteus vulgaris, Streptococcus faecalis, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes. No antimicrobial activity against the fungi was detected. It was determined that only one substance in the extracts has antimicrobial activity and it was characterized as protolichesterinic acid. The MICs of the extracts and protolichesterinic acid were also determined.


2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Flávia Cíntia de Oliveira ◽  
Tamara Rezende Marques ◽  
Gustavo Henrique Andrade Machado ◽  
Thaís Cristina Lima de Carvalho ◽  
Aline Aparecida Caetano ◽  
...  

Abstract The phenolic compounds from various extracts of jabuticaba skin powder (JSP) were characterized in this study, and the antibacterial activity assessed. The phenolic compounds were extracted from the JSP using four methods: a) acetone extraction - 1 g JSP: 10 mL 70% acetone, resting for 2 hours; b) aqueous extract - 1 g JSP: 15 mL water, under agitation; c) ethanolic extract - 1 g JSP: 15 mL acidified ethanol, under agitation; and d) methanolic extract - 1 g JSP: 50 mL 50% methanol, under reflux. The antibacterial activity was evaluated by the agar diffusion assay, using Escherichia coli ATCC 11229, Salmonella choleraesuis ATCC 6539, Pseudomonas aeruginosa ATCC 15442, Staphylococcus aureus ATCC 6538 and Listeria monocytogenes ATCC 19117. The ethanolic and methanolic extracts showed the highest levels of phenolic compounds, especially of cyanidin chloride, catechin and epicatechin. The extracts did not inhibit the growth of Escherichia coli and Salmonella choleraesuis, but inhibited 30% of the growth of Pseudomonas aeruginosa with an extract concentration of 250 µg mL-1. Against Staphylococcus aureus and Listeria monocytogenes the highest inhibitory effect observed was 41.8% for the ethanolic extract, followed by 36% inhibition by the methanolic extract, thus revealing the potential of these extracts as possible alternatives for use in the food and/or pharmaceutical industries.


Author(s):  
Umeh Odera Richard ◽  
E. I. Chukwura ◽  
Ibo Eziafakaego Mercy

A fish pond with recommended water quality will produce healthy fishes. Fish ponds with poor water quality will cause fish mortality and outbreak of diseases to fish consumers. Physicochemical analysis was done using standard analytical methods, the total bacterial count was determined by dilution and membrane filtration techniques. Parasitological analysis was done using the centrifugation method. A total of fifteen well waters were sampled during wet season. Results showed that the temperature ranged from 27°C to 29°C, pH, 6.21 to 8.15; dissolved oxygen, 4.28 mg/l to 5.78 mg/l, electrical conductivity, 166.36 µs/cm to 394.00 µs/cm; total dissolved solids, 41 mg/l to 121 mg/l; total suspended solids, 1.00 mg/l to 19.40 mg/l; total solids, 42.00 mg/l to 140.4 mg/l; turbidity values, 7.01 NTU to 10.36 NTU; nitrate, 3.10 mg/l to 28.00 mg/l; total alkalinity, 36 mg/l to 91 mg/l; phosphate, 1.26 mg/l to 13.11 mg/l; sulphate, 0.39 mg/l to 4.37 mg/l; total chloride, 7.08 mg/l to 14.19 mg/l; carbonates, 1.33 mg/l to 2.35 mg/l; bicarbonates, 34.59 mg/l to 89.38 mg/l; total hardness, 25.31 mg/l to 53.04 mg/l; calcium hardness, 23.94 mg/l to 51.96 mg/l; magnesium hardness, 1.08 mg/l to 4.20 mg/l; total acidity, 2 mg/l to 22 mg/l; potassium, 0.04 mg/l to 2.23 mg/l; cadmium, 0.00 mg/l to 0.04 mg/l; lead, 0.01 mg/l - 0.16 mg/l; chromium, 0.00 mg/l - 0.03 mg/l; mercury was not detected, copper, 0.00 mg/l - 0.04 mg/l; arsenic, 0.00 mg/l - 0.02 mg/l; zinc, 0.00 mg/l to 0.02 mg/l; iron, 0.01 mg/l - 1.19 mg/l. The total bacterial counts ranged from 3.60-4.12 log cfu/ml; total coliforms, 14-46 cfu/100ml, Vibrio cholerae, 0-11 cfu/100ml; Vibrio parahaemolyticus, 0-15 cfu/100ml; faecal coliform, 1-9 cfu/100 ml; Acinetobacter calcoaceticus, 0-8 cfu/100 ml; Bacillus subtilis, 0-9 cfu/ml; Staphylococcus aureus, 0-5 cfu/ml; Pseudomonas aeruginosa, 0-12 cfu/100 ml; Pseudomonas fluorescens, 0-12 cfu/100 ml and Clostridium perfringens were not detected in any of the samples. Twelve bacterial species namely Klebsiella pneumoniae, Acinetobacter calcoaceticus, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Pseudomonas fluorescens, Pseudomonas aeruginosa, Proteus mirabilis, Vibrio parahaemolyticus, Bacillus subtilis, Shigella flexineri and Salmonella typhi were isolated and identified using standard analytical and molecular procedures. Parasites identified were Ichthyobodo species, Diplostomum species, Myxobolus species, Chilodonella species, Bothriocephalus species, Ambiphrya species and Leech species. Salmonella typhi had the highest frequency of isolation (20.63%) while Acinetobacter calcoaceticus and Staphylococcus aureus had the lowest frequency of isolation (2.83%). Ichthyobodo species had the highest frequency of isolation (21.43%) while Leech species had the lowest frequency of isolation (5.71%). Some of the physicochemical, bacteriological and parasitological parameters had values above World Health Organization admissible limits and therefore proper sanitary practices and water treatments must be employed to prevent epidemic among fish consumers.


2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VĂN HỒNG THIỆN ◽  
LÊ BÍCH TRÂM ◽  
NGUYỄN THANH LAN ◽  
HỒ NGUYỄN HOÀNG YẾN ◽  
LƯU HỒNG TRƯỜNG ◽  
...  

Nghiên cứu này đã xác định được mẫu nghiên cứu thu tại Vườn quốc gia Phú Quốc là loài Homalomena pierreana. Thông qua kỹ thuật sắc ký ghép khối phổ, 10 hợp chất thuộc nhóm sesquiterpene có trong cao chiết ethanol của thân rễ loài H. pierreana đã được xác định. Ngoài ra, cao chiết ethanol từ mẫu nghiên cứu cũng cho thấy khả năng kháng lại 6 chủng vi khuẩn kiểm định là Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis và Salmonella typhimurium.


Author(s):  
LUCIANA HELENA MAIA PORTE ◽  
MARIA HELENA MIGUEZ ROCHA LEÃO ◽  
ALEXANDRE PORTE

Lactoferrina bovina (bLF), proveniente do soro de leite, foimicroencapsulada pela técnica de spray drying. Microcápsulascontendo 20 % de bLF foram produzidas, utilizando-se comomaterial de parede dextrina: amido octenilsuccinato (OSA) emdiferentes proporções: 100:00, 75:25, 50:50, 25:75 e 0:100 %.Foram avaliadas a cor e a estabilidade de cor das microcápsulassob armazenamento em ambientes com diferentes umidadesrelativas e a atividade antimicrobiana da lactoferrina liberadadas microcápsulas. As microcápsulas apresentaram cor clara etenderam a escurecer sob armazenamento em ambiente com altaumidade relativa. Verifi cou-se atividade inibitória das microcápsulasde bLF produzidas para diferentes bactérias Gram positivas(Bacillus subtilis CCT 2576, Staphylococcus aureus CCT 2740,Micrococcus luteus CCT 2692, Enterococcus faecium CCT 5079,Streptococcus faecium ATCC 10541, Rhodococcus equi CCT0541), Gram negativas (Pseudomonas aeruginosa ATCC 13388,Salmonella choleraesius CCT 4296, Escherichia coli CCT 0547) elevedura (Candida albicans ATCC 10231). A concentração inibitóriamínima (MIC) das microcápsulas variou de acordo com o microorganismotestado (MIC entre 2,5-100 mg.mL-1). Com exceção deB. subtilis (MIC entre 50-100 mg.mL-1 para as microcápsulas), aconcentração de bLF contida nas microcápsulas necessária parainibir o crescimento dos micro-organismos foi menor do que a bLFnativa. Esses resultados sugerem efeito de potencialização daatividade antimicrobiana da bLF após o processamento por spraydrying.


1999 ◽  
Vol 65 (3) ◽  
pp. 1312-1315 ◽  
Author(s):  
N. J. Rowan ◽  
S. J. MacGregor ◽  
J. G. Anderson ◽  
R. A. Fouracre ◽  
L. McIlvaney ◽  
...  

ABSTRACT The effects of high-intensity pulsed-light emissions of high or low UV content on the survival of predetermined populations ofListeria monocytogenes, Escherichia coli,Salmonella enteritidis, Pseudomonas aeruginosa,Bacillus cereus, and Staphylococcus aureus were investigated. Bacterial cultures were seeded separately on the surface of tryptone soya-yeast extract agar and were reduced by up to 2 or 6 log10 orders with 200 light pulses (pulse duration, ∼100 ns) of low or high UV content, respectively (P < 0.001).


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


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