Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Microsc Res Tech ; 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38468512

RESUMO

Silver infused ultrathin TiO2 nanowires (NWs) were synthesized via a single step solvothermal approach. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the newly synthesized nanocatalysts was tested for the textile waste treatment taking methylene blue (MB) as model pollutant under solar light irradiations. Nearly 96% photodegradation efficiency for MB was achieved within 20 min. Furthermore, the recyclability of the photocatalyst was also studied, and the material remained stable and effective up to four consecutive runs. RESEARCH HIGHLIGHTS: Precise size-controlled synthesis of Ag-incorporated titania nanowires (ATNWs) Controlled aspect ratios, with tunable lengths and diameters (100-3 nm) via precursor and surfactant optimization Demonstrated ATNWs' efficiency in degrading toxic dye, methylene blue (MB) 96% photodegradation efficiency for MB achieved within 20 min using 3 nm thick annealed TiO2 NWs Recyclability efficiency of photocatalyst, which remained stable and effective for up to four consecutive runs.

2.
Fitoterapia ; 168: 105541, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37178809

RESUMO

Three undescribed dammarane-type triterpene saponins, 20(S)-sanchirhinoside A7-A9 (1-3), together with seventeen known ones, were isolated from the roots of Panax notoginseng (Burk.) F. H. Chen. The chemical structures of the new compounds were determined by HR-MS and NMR experiments along with chemical methods. To the best of our knowledge, compound 1 was the firstly reported fucose-containing triterpene saponin from plants in the genus of Panax. Moreover, the in vitro neuroprotective effects of the isolated compounds were evaluated. Compounds 11-12 displayed remarkable protective effects against PC12 cells injured by 6-hydroxydopamine.


Assuntos
Fármacos Neuroprotetores , Panax notoginseng , Panax , Saponinas , Triterpenos , Ratos , Animais , Saponinas/farmacologia , Saponinas/química , Panax notoginseng/química , Fármacos Neuroprotetores/farmacologia , Estrutura Molecular , Triterpenos/farmacologia , Triterpenos/química , Panax/química , Damaranos
3.
Oman Med J ; 34(4): 302-307, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31360318

RESUMO

OBJECTIVES: We sought to determine the prevalence, pattern of causative organisms, and mortality of newborns with culture-proven late-onset sepsis (LOS) and to determine and compare the risk factors linked to late-onset gram-positive and late-onset gram-negative sepsis in Sultan Qaboos University Hospital (SQUH). METHODS: We conducted a cross-sectional retrospective study of data obtained between 1 January 2007 and 31 December 2014 (eight years) from infants in the neonatal intensive care unit (NICU) at SQUH. Infants born in SQUH (inborn) and other institutions (outborn) with positive blood cultures were included in the study. RESULTS: The total number of live births and admissions during the study period were 26 289 and 3559, respectively. The total number of infants identified with LOS were 125 of whom 69 (55.2%) were gram-positive, 52 (41.6%) were gram-negative, and four (3.2%) were due to Candida species (spp.). The majority of infants (n = 113, 90.4%) were inborn; 69 (55.2%) were males and 56 (44.8%) were females. The prevalence of LOS among inborn admissions was 4.3 per 1000 live births. Most infections occurred in very low birth weight infants (n = 81, 64.8%). Eleven (8.8%) infants died due to gram-negative sepsis. Klebsiella pneumoniae followed by Pseudomonas aeruginosa were the leading cause of death. Maternal intrapartum antibiotics were the only independent risk factor correlating with gram-negative organisms in multivariate analysis (p = 0.003). CONCLUSIONS: LOS poses a burden in the NICU, which could be due to the increasing survival of premature babies. The main contributing organisms to LOS are gram-positive bacteria. Klebsiella spp. is a major cause of mortality in LOS. The use of intrapartum antibiotic prophylaxis in mothers might explain the positive correlation of maternal antibiotics as a risk factor with gram-negative infections.

4.
Nat Prod Res ; 31(19): 2321-2324, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28288517

RESUMO

The project was intended to the phytochemical characterisation from the rudimentary methanolic extract of Chenopodium ambrosioides Linn., which escorts to the isolation of stigmasterol (1), ß-sitosterol (2), octadecanoic acid (3), scopoletin (4) and 1-piperoylpiperidine (5). Literature validates the medicinal authentication of these compounds extorted from other sources, while our previous findings regarding microbial activities of different solvent systems fractions are favouring the presence of medicinally important compounds in this species. Herein, however, we report these natural products for the first time from this species.


Assuntos
Chenopodium ambrosioides/química , Extratos Vegetais/química , Plantas Medicinais/química , Alcaloides/isolamento & purificação , Benzodioxóis/isolamento & purificação , Metanol/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Piperidinas/isolamento & purificação , Alcamidas Poli-Insaturadas/isolamento & purificação , Sitosteroides/isolamento & purificação , Solventes/química , Estigmasterol/isolamento & purificação
5.
Phytochemistry ; 136: 125-132, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28139298

RESUMO

Phytochemical investigation of the tubers of Ophiopogon japonicus led to the isolation of five previously undescribed steroidal saponins, ophiojaponins A-E, together with twelve known ones. The structures of these isolated compounds were elucidated by detailed spectroscopic analyses and chemical methods. Ophiojaponins A-C are rare naturally occurring C29 steroidal glycosides possessing a homo-cholestane skeleton with an aromatized ring E. Ruscogenin 1-O-α-L-rhamnopyranosyl-(1 â†’ 2)-4-O-sulfo-ß-D-fucopyranosido-3-O-ß-D-glucopyranoside was isolated as single component and its full spectroscopic data was reported for the first time. The isolated steroidal saponins were evaluated for their cytotoxicities against two human tumor cell lines MG-63 and SNU387. Among them, five known spirostane-type glycosides showed cytotoxic activity against both MG-63 and SNU387 cell lines with IC50 values ranging from 0.76 to 27.0 µM.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Colestanos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Ophiopogon/química , Tubérculos/química , Saponinas/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Colestanos/química , Colestanos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Estrutura Molecular , Saponinas/química , Saponinas/farmacologia , Estereoisomerismo
6.
Nat Prod Res ; 31(4): 428-435, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27187805

RESUMO

A new compound named as santolinylol-3-acetate (4-(2-hydroxypropan-2-yl)-2-methylhexa-1,5-dien-3-yl acetate) (3), along with seven known compounds; linoleic acid (1), benzoic acid (2), santolinylol (4), ethyl-(E)-p-hydroxy cinnamate (5), scopoletin (6), esculetin (7) isofraxidin (8) and eupatorin (9), were isolated from the aerial parts (ethanolic extract) of endangered species: Artemisia incisa Pamp (Asteraceae). The compounds' structures were determined through modern spectroscopic techniques, and comparison of data (physicochemical constants) with the literature. The relative stereochemistry of santolinylol-3-acetate (3) was determined by comparing its data of NOESY, and specific rotation with its diol analogue; santolinylol (4), isolated from the same plant; A. incisa. The results of the antifungal activity showed that coumarins are as whole less active compounds. Compounds 3 (25 and 300 µg/mL), and 4 (12.5 and 300 µg/mL), showed good activities against Candida albicans, and Aspergillus flavus, respectively, which justifies A. incisa as a traditional medicine for curing the said fungal infections.


Assuntos
Antifúngicos/isolamento & purificação , Artemisia/química , Monoterpenos/isolamento & purificação , Antifúngicos/química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Monoterpenos/química , Monoterpenos/farmacologia , Componentes Aéreos da Planta/química
7.
Nat Prod Res ; 29(17): 1664-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25604951

RESUMO

Bioassay-guided isolation and fractionation of Berberis jaeschkeana Schneid var. jaeschkeana stem resulted in the isolation and characterisation of a new long chain hydroxy ester named as berberinol (1) along with six known compounds (2-7). All the structures were established from 1D and 2D spectroscopic data. Crude extract, sub-fractions and all the isolated compounds were evaluated for their anti-fungal and urease enzyme inhibition properties. All of the sub-fractions and compounds showed good anti-fungal and urease enzyme inhibition properties. Minimum inhibitory concentrations (MICs) were calculated for all active samples in case of urease enzyme inhibition. MICs values were found to be in the range of 39.03-49.78 µg/mL for urease enzyme inhibition.


Assuntos
Antifúngicos/isolamento & purificação , Berberis/química , Extratos Vegetais/química , Caules de Planta/química , Urease/antagonistas & inibidores , Antifúngicos/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Ésteres/química , Ésteres/isolamento & purificação , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular
8.
Nat Prod Res ; 29(8): 692-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25424893

RESUMO

One new isoquinoline alkaloid named berberidione (1) along with four new source alkaloids berberine (2), palmatine (3), jatrorrhizine (4) and chondrofoline (5) and three new source non-alkaloids syringic acid (6), ß-sitosterol (7) and stigmasterol (8) was isolated and characterised from different fractions of Berberis jaeschkeana Schneid var. jaeschkeana. All the structures were determined from 1D and 2D spectroscopic data. Crude extract, sub-fractions and isolated compounds showed excellent anti-microbial properties. The toxicity level for the alkaloids was found to be very low on THP-1 cells.


Assuntos
Alcaloides/química , Antibacterianos/química , Berberis/química , Isoquinolinas/química , Alcaloides/isolamento & purificação , Antibacterianos/isolamento & purificação , Linhagem Celular , Humanos , Isoquinolinas/isolamento & purificação , Estrutura Molecular
9.
Fitoterapia ; 99: 92-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25250895

RESUMO

Four new neolignans, meliasendanins A-D (1-4), and a new glycoside, toosenoside A (5), together with ten known ones (6-15), were isolated from a n-BuOH partition of the fruits of Melia toosendan. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously. Meliasendanin A (1) was a rare neolignan containing isochroman moiety, and its absolute configuration was determined using a CD spectrum. Toosenoside A (5) was an unusual glycoside with a rare naturally occurring aglycone and its structure was confirmed by X-ray single crystal diffraction analysis. The antioxidant activity of the isolated neolignans and lignans was evaluated by ABTS radical-scavenging assay. Compounds 1 and 13 exhibited strong antioxidant activity, with IC50 values of 62.8 and 45.1 µM, respectively.


Assuntos
Antioxidantes/química , Glicosídeos/química , Lignanas/química , Melia/química , Antioxidantes/isolamento & purificação , Frutas/química , Glicosídeos/isolamento & purificação , Lignanas/isolamento & purificação , Estrutura Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...