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1.
J Org Chem ; 83(10): 5724-5730, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29684282

RESUMO

A carbocation cyclization/rearrangement mechanism for the biosynthesis of isothapsadiene and ß-isothapsenol is shown to be energetically viable on the basis of density functional theory (DFT) calculations. In addition, for both isothapsadiene and ß-isothapsenol, variable-temperature NMR experiments reveal two equilibrium conformers that undergo hindered exchange. The identities of these conformers, which are related by a chair-flip, are confirmed by DFT calculations on their structures, energies, 1H and 13C chemical shifts, and interconversion pathways.


Assuntos
Sesquiterpenos/química , Sesquiterpenos/metabolismo , Ciclização , Espectroscopia de Ressonância Magnética , Conformação Molecular , Teoria Quântica
2.
Int J Mol Sci ; 19(2)2018 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-29470390

RESUMO

Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5-30%, w/w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S. typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials.


Assuntos
Acroleína/análogos & derivados , Gelatina/química , Nanofibras/química , Nanotecnologia/métodos , Pele/química , Acroleína/química , Animais , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Emulsões , Peixes , Nanofibras/ultraestrutura , Tamanho da Partícula , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Tensão Superficial , Viscosidade
3.
J Sep Sci ; 40(7): 1449-1456, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28139056

RESUMO

The peels of different pomegranate cultivars (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) were compared in terms of phenolic composition and total phenolics. Analyses were performed on two silica hydride based stationary phases: phenyl and undecanoic acid columns. Quantitation was accomplished by developing a liquid chromatography with mass spectrometry approach for separating different phenolic analytes, initially in the form of reference standards and then with pomegranate extracts. The high-performance liquid chromatography columns used in the separations had the ability to retain a wide polarity range of phenolic analytes, as well as offering beneficial secondary selectivity mechanisms for resolving the isobaric compounds, catechin and epicatechin. The Vkunsyi peel extract had the highest concentration of phenolics (as determined by liquid chromatography with mass spectrometry) and was the only cultivar to contain the important compound punicalagin. The liquid chromatography with mass spectrometry data were compared to the standard total phenolics content as determined by using the Folin-Ciocalteu assay.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia Líquida de Alta Pressão , Lythraceae/química , Fenóis/química , Extratos Vegetais/química , Silicatos/química , Técnicas de Química Analítica/instrumentação , Cromatografia Líquida de Alta Pressão/instrumentação , Espectrometria de Massas
4.
J Food Sci ; 89(3): 1347-1360, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38258913

RESUMO

Pomegranate juice was treated by isochoric freezing (-15°C/130 MPa) for 24 h and then stored under three different conditions for up to 4 weeks: 4°C/0.1 MPa, 24°C/0.1 MPa, and -10°C/100 MPa. The juice microbiological stability and quality were compared to those using heat treatment at 95°C for 15 s followed by cold storage at 4°C. Heat-treated and isochoric frozen (IF) pomegranate juice stored under isochoric conditions showed no spoilage microorganisms after 4 weeks of storage. Also, IF juice stored at 4 or 24°C for 4 weeks had lower microbial loads than those in fresh pomegranate juice. IF juice stored under isochoric conditions showed greater color stability, antioxidant capacity, and nutrient retention (anthocyanins, ascorbic acid, and total phenolic compounds) than heat-treated juices stored at 4°C. IF juice stored at 4°C also showed greater anthocyanin and ascorbic acid contents compared with heat-treated juice. PRACTICAL APPLICATION: Isochoric freezing storage at -10°C can be used to preserve the quality properties of fresh pomegranate juice. Isochoric freezing at -15°C for 24 h can also be used as a pretreatment to extend the shelf life of refrigerated pomegranate juice since the applied pressures reached total inactivation levels of spoilage microorganisms.


Assuntos
Punica granatum , Congelamento , Antocianinas , Antioxidantes , Ácido Ascórbico
5.
J Food Sci ; 89(6): 3167-3182, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38638061

RESUMO

Isochoric (constant volume) freezing is a novel food preservation technology that has demonstrated the ability to preserve food products at subfreezing temperatures in an unfrozen state, thereby avoiding the detrimental effects of ice formation. It minimizes the quality loss of fresh fruits and juices, increases their nutrient content, and reduces microbial counts. Orange juice (OJ) samples were subjected to conventional freezing (CF) and isochoric freezing (IF) for 7 days and then stored at 4°C for an additional 7 days. We evaluated the microbiological and physicochemical quality of CF and IF OJ before and after storage. The IF was performed at three different conditions: -5°C/73 MPa, -10°C/93 MPa, and -15°C/143 MPa. The results indicate that the total aerobic count of OJ remained below the detection limit after heat treatment, 7 days of CF and 7 days of IF. Yeast and mold counts increased in fresh and CF OJ after 7 days of storage at 4°C, whereas IF OJ remained below the detection limit. Less color difference was observed in IF (-15°C/143 MPa) OJ compared to heat-treated and CF OJ. Heat treatment inactivated 42% of pectin methylesterase (PME), whereas 7-day long IF increased PME activity up to 150%. Additionally, IF (-15°C/143 MPa) OJ showed reduced pulp sedimentation, which can be advantageous, as sedimentation in juices has been a recognized technological issue in the juice industry. Ascorbic acid level was significantly higher in IF (-15°C/143 MPa) OJ compared to fresh and CF OJ after storage.


Assuntos
Citrus sinensis , Conservação de Alimentos , Congelamento , Sucos de Frutas e Vegetais , Citrus sinensis/microbiologia , Citrus sinensis/química , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Conservação de Alimentos/métodos , Hidrolases de Éster Carboxílico/análise , Armazenamento de Alimentos/métodos , Contagem de Colônia Microbiana , Frutas/microbiologia , Frutas/química , Microbiologia de Alimentos/métodos , Cor
6.
Foods ; 12(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38002207

RESUMO

This study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw milk in isochoric chambers in thermodynamic equilibrium at -5 °C/77 MPa and -10 °C/96 MPa. Several parameters were analyzed, including microbiology count, physicochemical properties, indigenous enzyme activity, protein content, volatile organic compounds profile, and lipid degradation. Both raw and pasteurized milk experienced increases in the microbial level past the acceptable threshold (≥5.5 log CFU/mL) after 2 weeks and 5 weeks, respectively, leading to the deterioration of other parameters during storage. In comparison, microbiology count decreased significantly during storage for both IF treatment conditions but was more pronounced for the higher pressure (96 MPa) treatment, leading to undetectable levels of microorganism after 5 weeks. IF treatment maintained stable pH, titratable acidity, viscosity, lipid oxidation, volatile profiles, total protein content, and lactoperoxidase activity throughout the storage period. Color was preserved during IF treatment at -5 °C/77 MPa; however, color was impacted during IF treatment at -10 °C/96 MPa. Protein structures were also modified during pressurized storage in both IF treatments. Overall, the study demonstrated that isochoric freezing could significantly increase the shelf-life of milk by reducing microbiology activity, whilst maintaining its nutritional content. These results underscore the potential role of isochoric freezing as a valuable tool in eliminating pathogens while maintaining quality characteristics similar to raw milk over long storage periods.

7.
J Food Sci ; 87(11): 4796-4807, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36181485

RESUMO

Isochoric impregnation was explored as a novel pressure-assisted infusion technique to fortify plant materials with bioactive compounds. Apple and potato cylinders were impregnated with a sucrose solution containing 4% ascorbic acid (AA) while freezing under isochoric conditions. Isochoric impregnation resulted in greater infusion of AA compared to infusion at atmospheric pressure, which demonstrated the feasibility of this impregnation technology. Processing temperatures (-3°C and -5°C) and processing times (1, 3, and 5 h) significantly affected the AA infusion. The AA content values ranged from 446 to 516 mg/100 g for apples and 322 to 831 mg/100 g for sweet potatoes under isochoric conditions. For both plant materials, isochoric impregnation at -3°C did not cause major changes in texture and microstructure of the biological tissues. These results indicated that isochoric impregnation of solid foods could be a feasible technology for infusion of bioactive compounds without significantly altering their matrix. PRACTICAL APPLICATION: The findings of this study showed that the use of isochoric impregnation as a fortification technique is a promising way to develop fresh-like and value-added products with improved nutrition during preservation at subfreezing temperatures.


Assuntos
Malus , Solanum tuberosum , Isocoros , Congelamento , Ácido Ascórbico
8.
Food Res Int ; 143: 110228, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33992342

RESUMO

This study investigated the potential of isochoric freezing to preserve tomatoes. Isochoric freezing is an emerging technology that preserves biological matter at subfreezing temperatures without any ice damage. Isochoric freezing was compared with freezing under isobaric conditions and with preservation techniques used in the food industry: cold storage at 10 °C and individual quick freezing (IQF). Physicochemical and nutritional properties were evaluated weekly for four weeks. Preservation under isochoric conditions maintained the mass, color, nutrient content (ascorbic acid, lycopene and phenolics) and antioxidant activity of the fresh tomatoes. Also, isochoric preservation led to minimal texture damage. In comparison, mass loss of tomatoes stored at 10 °C for 3 weeks contributed to changes in overall visual quality and firmness as well as significant losses in nutrient content. The greatest mass, texture, and nutrients losses were obtained for tomatoes subjected to IQF and isobaric freezing. The results show that isochoric freezing has the potential to preserve tomatoes while maintaining physicochemical and nutritional properties similar to those of fresh tomatoes which might find application in the commercial preservation of tomatoes.


Assuntos
Solanum lycopersicum , Vitis , Criopreservação , Congelamento , Isocoros
9.
J Food Sci ; 85(9): 2656-2664, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32860220

RESUMO

The enhanced interest in greater convenience foods has recently led to the expansion of minimally processed potato products. This study investigated the effects of isochoric freezing on pre-peeled potato cubes, including quality attributes (microstructure, texture, and color), nutritional value (ascorbic acid (AA) content, total phenolic content, and antioxidant capacity), and polyphenol oxidase activity. Isochoric freezing (-3 °C/30 MPa) was compared with isobaric freezing (-3 °C/0.1 MPa) and individual quick freezing followed by frozen storage at -20 °C for 4 weeks. The isochoric sample had lower drip loss and volume shrinkage as well as better preserved texture and microstructure than the other samples. All freezing methods caused an increase in total phenolic content and antioxidant capacity, but a decrease in AA content. Also, all freezing methods caused browning of the thawed potatoes, but isochoric freezing delayed its onset for more than 1 week. PRACTICAL APPLICATION: Results showed that isochoric freezing of pre-peeled and cut potatoes caused less freeze damage than isobaric and individual quick freezing, which might find application in the commercial preservation of minimally processed food products.


Assuntos
Conservação de Alimentos/métodos , Tubérculos/química , Solanum tuberosum/química , Antioxidantes/análise , Ácido Ascórbico/análise , Congelamento , Valor Nutritivo , Oxirredução , Fenóis/análise
10.
J Agric Food Chem ; 56(10): 3749-57, 2008 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-18459793

RESUMO

Three tasty (BR-139, FA-624, and FA-612) and two less tasty (R-144 and R-175) fresh greenhouse tomato cultivars, which significantly differ in their flavor profiles, were screened for potent odorants using aroma extract dilution analysis (AEDA). On the basis of AEDA results, 19 volatiles were selected for quantification in those 5 cultivars using gas chromatography-mass spectrometry (GC-MS). Compounds such as 1-penten-3-one, ( E, E)- and ( E, Z)-2,4-decadienal, and 4-hydroxy-2,5-dimethyl-3(2 H)-furanone (Furaneol) had higher odor units in the more preferred cultivars, whereas methional, phenylacetaldehyde, 2-phenylethanol, or 2-isobutylthiazole had higher odor units in the less preferred cultivars. Simulation of the odor of the selected tomato cultivars by preparation of aroma models and comparison with the corresponding real samples confirmed that all important fresh tomato odorants were identified, that their concentrations were determined correctly in all five cultivars, and that differences in concentration, especially of the compounds mentioned above, make it possible to distinguish between them and are responsible for the differential preference. To help elucidate formation pathways of key odorants, labeled precursors were added to tomatoes. Biogenesis of cis- and trans-4,5-epoxy-( E)-2-decenals from linoleic acid and methional from methionine was confirmed.


Assuntos
Aldeídos/química , Compostos de Epóxi/química , Frutas/química , Odorantes/análise , Solanum lycopersicum/química , Adulto , Idoso , Aldeídos/metabolismo , Compostos de Epóxi/metabolismo , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Olfato , Paladar , Volatilização
11.
Phytother Res ; 22(9): 1195-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18697182

RESUMO

Piperlongumine, a pyridone alkaloid isolated from Piper longum L., exhibited a potential inhibitory effect on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA) and platelet activating factor (PAF), without any inhibitory effect on that induced by thrombin. Piperlongumine was used as a lead compound for the synthesis of new antiplatelet agents. Seven synthetic compounds were newly synthesized from 3,4,5-trimethoxycinnamic acid (TMCA). They were 1-piperidin-1-yl-3-(3,4,5-trimethoxy-phenyl)prop-2-en-1-one (1'), 1-morpholin-4-yl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (2'), 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3'), 1-(2-methylpiperidin-1-yl)-3-(3,4,5-tri-methoxyphenyl)prop-2-en-1-one (4'), 1-(3-hydroxypiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)- prop-2-en-1-one (5'), 1-[3-(3,4,5-tri-methoxyphenyl) acryloyl]-piperidin-2-one (6') and ethyl 1-[3-(3,4,5-trimethoxyphenyl)-acryloyl]piperidine-4-carboxylate (7'). Among those seven synthetic derivatives, 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3') had the most inhibitory effect on platelet aggregation induced by collagen, AA and PAF.


Assuntos
Dioxolanos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Animais , Dioxolanos/química , Técnicas In Vitro , Masculino , Inibidores da Agregação Plaquetária/química , Coelhos , Análise Espectral/métodos
12.
J Food Sci ; 83(4): 984-991, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29577286

RESUMO

Carvacrol is a volatile monoterpenic phenol and main component of oregano essential oil that shows nonspecific antimicrobial activity against foodborne pathogenic bacteria. Fish-skin gelatin (FSG) nanofibers encapsulating carvacrol (15%, 20%, 25%, and 30%, w/w FSG) were successfully prepared via solution blow-spinning (SBS) technique using lecithin (2.475% wb) as the surfactant. FSG emulsions with lower carvacrol ratios (5% and 10%) showed higher values in particle size and surface tension as well as lower values in viscosity and modulus, which led to failure of maintaining nanofibers shape. The formed carvacrol-FSG nanofibers showed round and smooth morphologies with average fiber diameters ranging from 103.2 to 138.1 nm as the carvacrol ratio increased from 15% to 30%. Carvacrol was evenly dispersed within the interior of nanofiber matrix. All carvacrol-FSG nanofibers showed inhibitive effects against the growth of Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Moreover, nanofibers with lower carvacrol ratios showed bigger inhibition zones for E. coli and L. monocytogenes (20 mm compared with 12.5 mm for lowest to highest carvacrol ratios, respectively). Nanofibers stored at 20 °C (51% RH) showed better retention (40% to 60%) for carvacrol during the first 4 weeks of storage, while nanofibers stored at 2 °C (70% RH) showed better retention (10% to 30%) at the end of storage. PRACTICAL APPLICATION: Results obtained in the study may help with antimicrobial carvacrol addition levels for gelatin fiber preparation using solution blow spinning (SBS) method. SBS gelatin fibers with added antimicrobials have potential applications for food packaging and medical wound dressing.


Assuntos
Bactérias/efeitos dos fármacos , Proteínas de Peixes/farmacologia , Conservação de Alimentos/métodos , Gelatina/farmacologia , Monoterpenos/farmacologia , Nanofibras , Óleos Voláteis/farmacologia , Animais , Antibacterianos/farmacologia , Cimenos , Escherichia coli/efeitos dos fármacos , Peixes , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Listeria monocytogenes/efeitos dos fármacos , Monoterpenos/administração & dosagem , Óleos Voláteis/administração & dosagem , Origanum/química , Extratos Vegetais/farmacologia , Salmonella enterica/efeitos dos fármacos , Pele , Soluções/química , Viscosidade
13.
Food Chem ; 264: 449-454, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29853400

RESUMO

Methylenecyclcopropylglycine (MCPG) and hypoglycin A (HGA) are naturally occurring amino acids found in various soapberry (Sapindaceae) fruits. These toxins have been linked to illnesses worldwide and were recently implicated in Asian outbreaks of acute hypoglycemic encephalopathy. In a previous joint agricultural and public health investigation, we developed an analytical method capable of evaluating MCPG and HGA concentrations in soapberry fruit arils as well as a clinical method for the urinary metabolites of the toxins. Since the initial soapberry method only analyzed the aril portion of the fruit, we present here the extension of the method to include the fruit seed matrix. This work is the first method to quantitate both MCPG and HGA concentrations in the seeds of soapberry fruit, including those collected during a public health investigation. Further, this is the first quantitation of HGA in litchi seeds as well as both toxins in mamoncillo and longan seeds.


Assuntos
Cromatografia Líquida de Alta Pressão , Ciclopropanos/análise , Glicina/análogos & derivados , Hipoglicinas/análise , Sapindus/metabolismo , Espectrometria de Massas em Tandem , Frutas/química , Frutas/metabolismo , Glicina/análise , Sementes/metabolismo
14.
Lancet Glob Health ; 5(4): e458-e466, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28153514

RESUMO

BACKGROUND: Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country's largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. METHODS: In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). FINDINGS: Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9·6 [95% CI 3·6 - 24]) and absence of an evening meal (2·2 [1·2-4·3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7·8 [95% CI 3·3-18·8], without evening meal; OR 3·6 [1·1-11·1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 µg/g to 152·0 µg/g and MCPG ranged from 44·9 µg/g to 220·0 µg/g. INTERPRETATION: Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks. FUNDING: US Centers for Disease Control and Prevention.


Assuntos
Encefalopatia Aguda Febril/diagnóstico , Surtos de Doenças/estatística & dados numéricos , Frutas/toxicidade , Litchi/toxicidade , Síndromes Neurotóxicas/diagnóstico , Encefalopatia Aguda Febril/epidemiologia , Encefalopatia Aguda Febril/etiologia , Adolescente , Estudos de Casos e Controles , Criança , Ciclopropanos/análise , Feminino , Glicina/análogos & derivados , Glicina/análise , Humanos , Hipoglicinas/análise , Índia , Masculino , Síndromes Neurotóxicas/epidemiologia , Síndromes Neurotóxicas/etiologia , Razão de Chances
15.
J Ethnopharmacol ; 105(1-2): 255-62, 2006 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16359837

RESUMO

The growth-inhibiting activity of Tabebuia impetiginosa Martius ex DC dried inner bark-derived constituents against Helicobacter pylori ATCC 43504 was examined using paper disc diffusion and minimum inhibitory concentration (MIC) bioassays. The activity of the isolated compounds was compared to that of the commercially available anti-Helicobacter pylori agents, amoxicillin, metronidazole, and tetracycline. The biologically active components of Tabebuia impetiginosa dried inner bark (taheebo) were characterized by spectroscopic analysis as 2-(hydroxymethyl)anthraquinone, anthraquinone-2-carboxylic acid, and 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol). With the paper disc diffusion assay 2-(hydroxymethyl)anthraquinone exhibited strong activity against Helicobacter pylori ATCC 43504 at 0.01 mg/disc. Anthraquinone-2-carboxylic acid, lapachol and metronidazole were less effective, exhibiting moderate anti-Helicobacter pylori activity at 0.1 mg/disc. Amoxicillin and tetracycline were the most potent compounds tested, displaying very strong activity at 0.005 mg/disc. 2-(Hydroxymethyl)anthraquinone exhibited moderate activity at this dose. Tetracycline still had strong activity at 0.001 mg/disc while amoxicillin had little activity at this dose. In the MIC bioassay, 2-(hydroxymethyl)anthraquinone (2 microg/mL), anthraquinone-2-carboxylic acid (8 microg/mL), and lapachol (4 microg/mL) were more active than metronidazole (32 microg/mL) but less effective than amoxicillin (0.063 microg/mL) and tetracycline (0.5 microg/mL). The anti-Helicobacter pylori activity of seven 1,4-naphthoquinone derivatives (structurally related to lapachol), 1,4-naphthoquinone, 5,8-dihydroxy-1,4-naphthoquinone (naphthazarin), 2-methyl-1,4-naphthoquinone (menadione), 2-hydroxy-1,4-naphthoquinone (lawsone), 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin), 5-hydroxy-1,4-naphthoquinone (juglone), and 2,3-dichloro-1,4-naphthoquinone (dichlone) was also evaluated using the paper disc assay. Menadione and plumbagin were the most potent compounds tested with the later still exhibiting very strong activity at 0.001 mg/disc. Menadione, juglone and tetracycline had strong activity at this low dose while the latter two compounds and amoxicillin had very strong activity at 0.005 mg/disc. Lawsone was unusual in that it had very strong activity at 0.1 and 0.05 mg/disc but weak activity at doses of 0.01 mg/disc and lower. Naphthazalin, lapachol and dichlone had similar activities while metronidazole had the lowest activity of all compounds tested. These results may be an indication of at least one of the pharmacological actions of taheebo. The Tabebuia impetiginosa dried inner bark-derived materials, particularly 2-(hydroxymethyl)anthraquinone, merit further study as potential Helicobacter pylori eradicating agents or lead compounds.


Assuntos
Antibacterianos/farmacologia , Helicobacter pylori/efeitos dos fármacos , Extratos Vegetais/farmacologia , Tabebuia/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas/métodos , Testes de Sensibilidade Microbiana , Espectroscopia de Infravermelho com Transformada de Fourier
16.
J Ethnopharmacol ; 108(1): 148-51, 2006 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-16766151

RESUMO

The antiplatelet and antiproliferative activities of extract of Tabebuia impetiginosa inner bark (taheebo) were investigated using washed rabbit platelets and cultured rat aortic vascular smooth muscle cells (VSMCs) in vitro. n-Hexane, chloroform and ethyl acetate fractions showed marked and selective inhibition of platelet aggregation induced by collagen and arachidonic acid (AA) in a dose-dependent manner. These fractions, especially the chloroform fraction, also significantly suppressed AA liberation induced by collagen in [(3)H]AA-labeled rabbit platelets. The fractions, especially the chloroform fraction, potently inhibited cell proliferation and DNA synthesis induced by platelet derived growth factor (PDGF)-BB, and inhibited the levels of phosphorylated extracellular signal regulated kinase (ERK1/2) mitogen activated protein kinase (MAPK) stimulated by PDGF-BB, in the same concentration range that inhibits VSMC proliferation and DNA synthesis.


Assuntos
Ácido Araquidônico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Casca de Planta/química , Preparações de Plantas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Tabebuia/química , Animais , Proliferação de Células/efeitos dos fármacos , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Preparações de Plantas/química , Coelhos , Ratos
17.
J Food Sci ; 81(4): E889-96, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26989993

RESUMO

A current trend in olive mill wastewater (OMWW) management is to not only decrease environmental pollution but also to extract and utilize valuable by-products. Therefore, the objectives of this study were to explore different techniques for drying a phenolic-rich membrane filtration fraction of OMWW and compare the techniques in terms of the dried product quality and feasibility of the process. The OMWW from 2 (3-phase and 2-phase) California mills was subjected to a 2-step membrane filtration process using a novel vibratory system. The reverse osmosis retentate (RO-R) is a phenolic-rich coproduct stream, and the reverse osmosis permeate is a near-pure water stream that could be recycled into the milling process. Spray-, freeze-, and infrared-drying were applied to obtain solid material from the RO-R. Drying of the RO-R was made possible only with addition of 10% maltodextrin as a carrier. The total soluble phenolics in dried RO-R were in the range 0.15 to 0.58 mg gallic acid equivalents/g of dry weight for 2-phase RO-R, and 1.38 to 2.17 mg gallic acid equivalents/g of dry weight for the 3-phase RO-R. Spray-dried RO-R from 3-phase OMWW showed remarkable antioxidant activity. Protocatechuic acid, tyrosol, vanillic acid, and p-coumaric acid were quantified in all dried RO-R, whereas 3-hydroxytyrosol was found in 3-phase dried RO-R. This combination of separation and drying technologies helps to add value and shelf-stability to an olive oil by-product and increase environmental sustainability of its production.


Assuntos
Antioxidantes/análise , Dessecação/métodos , Filtração , Indústria Alimentícia , Olea/química , Fenóis/análise , Águas Residuárias , California , Ácidos Cumáricos/análise , Ácido Gálico/análise , Hidroxibenzoatos/análise , Resíduos Industriais/análise , Azeite de Oliva , Oxirredução , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/análise , Extratos Vegetais/isolamento & purificação , Polissacarídeos , Propionatos , Reciclagem , Ácido Vanílico/análise
18.
J Agric Food Chem ; 64(27): 5607-13, 2016 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-27367968

RESUMO

Methylenecyclopropylglycine (MCPG) and hypoglycin A (HGA) are naturally occurring amino acids found in some soapberry fruits. Fatalities have been reported worldwide as a result of HGA ingestion, and exposure to MCPG has been implicated recently in the Asian outbreaks of hypoglycemic encephalopathy. In response to an outbreak linked to soapberry ingestion, the authors developed the first method to simultaneously quantify MCPG and HGA in soapberry fruits from 1 to 10 000 ppm of both toxins in dried fruit aril. Further, this is the first report of HGA in litchi, longan, and mamoncillo arils. This method is presented to specifically address the laboratory needs of public-health investigators in the hypoglycemic encephalitis outbreaks linked to soapberry fruit ingestion.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclopropanos/análise , Frutas/química , Glicina/análogos & derivados , Hipoglicinas/análise , Sapindaceae/química , Espectrometria de Massas em Tandem/métodos , Ciclopropanos/toxicidade , Frutas/toxicidade , Glicina/análise , Glicina/toxicidade , Hipoglicinas/toxicidade , Sapindaceae/toxicidade
19.
J Agric Food Chem ; 53(12): 4932-7, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15941338

RESUMO

A major anthocyanin was isolated from the acidified methanolic extract of Beluga black lentils by XAD7 column chromatography and preparative high-performance liquid chromatography. By means of electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopy, its structure was determined to be delphinidin 3-O-(2-O-beta-D-glucopyranosyl-alpha-l-arabinopyranoside).


Assuntos
Antocianinas/análise , Lens (Planta)/química , Sementes/química , Antocianinas/química , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray
20.
J Agric Food Chem ; 53(19): 7630-6, 2005 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-16159196

RESUMO

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The solvent was evaporated, and the resulting solid was subsequently analyzed by high-performance liquid chromatography (HPLC), electrospray ionization mass spectrometry (ESI/MS), tandem mass spectrometry (ESI/MS/MS), and elemental analysis (by proton-induced X-ray emission analysis). Three major constituents were observed by HPLC and were identified as benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, and benzyldimethylhexadecylammonium chloride. This mixture of homologues is commonly known as benzalkonium chloride, a widely used synthetic antimicrobial ingredient used in cleaning and disinfection agents.


Assuntos
Compostos de Benzalcônio/análise , Citrus paradisi/química , Sementes/química , Clorofórmio , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria por Raios X
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