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










Base de dados
Intervalo de ano de publicação
1.
Exp Eye Res ; 235: 109629, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37625574

RESUMO

Chrysanthemum tea is commonly consumed by Chinese consumers mainly due to the Chrysanthemum flower being a potential source of antioxidants. The current study investigates the effects of extraction time and temperature on Chrysanthemum flower aqueous extract (CFAE) antioxidant capacity, including Trolox equivalent antioxidant capacity (TEAC), ferrous iron-chelating activity, and superoxide radical scavenging capacity (SRSC) using a two-factor, three-level factorial design of the response surface method (RSM). The TEAC and SRSC of CFAE are higher at higher temperatures and longer times up to a certain point, and the highest TEAC and SRSC are achieved at a 100 °C extraction temperature for 45 min. The fructose induced-αA-crystallin (Cry) glycation model system was used to evaluate the effects of the CFAE on anti-glycoxidation activities. The antioxidant ingredients obtained from CFAE significantly impede the production of advanced glycation end products from protein glycoxidation products (dityrosine, kynurenine, and N'-methylkynurenine) in the glycation process of αA-Cry and exhibit strong anti-glycating activity. The glycation inhibitory effects of CFAE are concentration-dependent. C. indicum L. exhibits greater potential for preventing cataracts compared to C. morifolium Ramat CFAE's antioxidant and anti-glycation properties suggest its potential application as a natural ingredient in the development of agents to combat glycation.


Assuntos
Chrysanthemum , Cristalinas , Humanos , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Flores
2.
Sci Rep ; 8(1): 14263, 2018 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-30250207

RESUMO

Sleep disturbance is a common complaint in cancer patients. However, less is known about the parameters of sleep in patients with nasopharyngeal cancer (NPC) and their family caregivers (FCs) when they are about to begin treatment. We investigated the sleep quality in patients with NPC and their FCs before treatment and determined the related factors that predict sleep disturbance in these patients before therapy. A total of 101 patient-FC dyads were recruited. They completed the Pittsburgh Sleep Quality Index (PSQI) prior to treatment. No differences were found in sleep disturbance between patients (38.6%) and their FCs (31.7%). Patients reported significantly higher rates of short sleep duration than their FCs (P = 0.011). Logistic regression analyses showed that older patients were more prone to suffer from poor sleep quality before treatment (OR = 1.06, 95% CI = 1.01-1.10, P = 0.008), while patients with a higher BMI were less likely to experience sleep disturbance (OR = 0.83, 95% CI = 0.71-0.96, P = 0.012). Sleep disturbance is a significant problem in patients with NPC and their FCs before therapy. Older patients and those with a lower BMI appear to be more inclined to suffer from poor sleep before treatment.


Assuntos
Cognição/fisiologia , Carcinoma Nasofaríngeo/epidemiologia , Transtornos do Sono-Vigília/epidemiologia , Sono/fisiologia , Adulto , Idoso , Cuidadores/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/complicações , Carcinoma Nasofaríngeo/patologia , Transtornos do Sono-Vigília/complicações , Transtornos do Sono-Vigília/patologia
3.
Chem Biol Interact ; 290: 12-18, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29753610

RESUMO

Macrophages and inflammasome pathway are involved in high-glucose toxicity and development of insulin resistance. Silymarin (SMR) was known to modulate glucose homeostasis and reduce inflammation. However, it is still unknown whether SMR possess anti-hyperglycemic effects in diabetic-like knockout mice (Hnf-1αkin/-/Ins.cre mice) with insulin resistance and also unclear how SMR regulates LPS induced stress markers and pro-inflammatory cytokines under stresses of high glucose (HG) or NLRP3 inflammasome activation. Current results show that oral administration of SMR (100 mg/kg) reduced hyperglycemia in the mouse model of maturity-onset diabetes of the young type 3-like mice. In cultured macrophages, SMR (5-20 µg/ml) reduces high glucose (HG)-enhanced expressions of inducible nitric oxide synthase, nitric oxide generation stimulated by LPS; however, no effects on COX-2 expressions. The enhanced interleukin-1ß (ΙL-1ß) secretions in the presence of HG or palmitate were also significantly down regulated by SMR in dose-dependent manner in LPS-treated macrophages. Such observations may result from the decreased extracellular signal-regulated kinase 1/2 phosphorylation, while without affecting protein kinase C-α phosphorylation and nuclear factor-κB activation. These findings together show that SMR acts as a protector against HG-related stresses not only by lowering hyperglycemia but also suppressing HG- and inflammasome-mediated IL-1ß expressions to improve insulin resistance.


Assuntos
Glucose/farmacologia , Hiperglicemia/patologia , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Silimarina/farmacologia , Animais , Linhagem Celular , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Fator 1-alfa Nuclear de Hepatócito/deficiência , Fator 1-alfa Nuclear de Hepatócito/genética , Hiperglicemia/tratamento farmacológico , Hiperglicemia/metabolismo , Inflamassomos/efeitos dos fármacos , Resistência à Insulina , Interleucina-1beta/genética , Lipopolissacarídeos/toxicidade , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação/efeitos dos fármacos , Células RAW 264.7 , Silimarina/uso terapêutico
4.
Angew Chem Int Ed Engl ; 57(24): 7040-7045, 2018 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-29664161

RESUMO

Traditional medicines provide a fertile ground to explore potent lead compounds, yet their transformation into modern drugs is fraught with challenges in deciphering the target that is mechanistically valid for its biological activity. Herein we reveal that (Z)-(+)-isochaihulactone (1) exhibited significant inhibition against multiple-drug-resistant (MDR) cancer cell lines and mice xenografts. NMR spectroscopy showed that 1 resisted an off-target thiolate, thus indicating that 1 was a target covalent inhibitor (TCI). By identifying the pharmacophore of 1 (α,ß-unsaturated moiety), a probe derived from 1 was designed and synthesized for TCI-oriented activity-based proteome profiling. By MS/MS and computer-guided molecular biology approaches, an affinity-driven Michael addition of the noncatalytic C247 residue of GAPDH was found to control the "ON/OFF" switch of apoptosis through non-canonically nuclear GAPDH translocation, which bypasses the common apoptosis-resistant route of MDR cancers.


Assuntos
4-Butirolactona/análogos & derivados , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzodioxóis/farmacologia , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , 4-Butirolactona/farmacologia , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Camundongos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Espectrometria de Massas em Tandem
5.
Int J Biol Macromol ; 113: 601-606, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29486260

RESUMO

Black soybeans are commonly consumed as health foods and used in traditional Chinese medicine, but they are rarely cultivated as edible sprouts. During germination, the composition of seeds undergoes distinct changes that cause variations in bioactivities. In this study, the water-soluble black soybean polysaccharide (BSPS) was isolated from sprouts harvested at two-day intervals during the first week of seedling growth. The chromatographic profiles of the BSPS in ungerminated seeds showed fraction 1 (F1, about 64kDa) and fraction 2 (F2, <1kDa) that degraded during germination. The polysaccharide in F1 fraction of ungerminated seeds was covalently associated with the protein and mainly contained arabinose, galactose, glucose, and galacturonic acid at various levels during germination. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging activities and the reducing power of F1 were highest on the seventh day of germination. The phenolic and flavonoid content significantly increased after the fifth day of germination, suggesting that these ingredients also contributed to the antioxidant activities. During long-term germination, the polysaccharide-protein conjugate in the F1 fraction with enhanced antioxidant activities is regarded as a potential natural antioxidant for the development of functional foods.


Assuntos
Antioxidantes/metabolismo , Germinação , Glycine max/crescimento & desenvolvimento , Glycine max/metabolismo , Proteínas de Plantas/metabolismo , Polissacarídeos/metabolismo , Antioxidantes/química , Monossacarídeos/análise , Proteínas de Plantas/química , Polissacarídeos/química
6.
Nat Prod Res ; 32(24): 2959-2963, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29067817

RESUMO

The objective of this study was to evaluate the antioxidant activities of Mesona procumbens ethanolic extracts (MPEEs) which displayed variable antioxidant levels with different ethanolic concentrations. Compared to MPEEs with 20, 40 and 80% ethanol, the 60% MPEE exhibited a higher total phenol content (TPC), total flavonoid content (TFC), 1,1-diphenyl-2-picryl hydrazyl (DPPH)- and 2,2-azino-bis-(3-ethyl benzothiazoline-6-sulphonic acid (ABTS)-scavenging activities, reducing power, protection of Raw 264.7 mouse macrophages against H2O2-induced damage, and inhibition of reactive oxygen species (ROS) induced by 2,2-azobis(2-amidino propane) dihidrochloride (AAPH). IC50 values of DPPH and ABTS radicals by MPEEs were highly and significantly associated with TPCs and TFCs. The most significant protective effect against oxidative DNA damage was also found to be the 60% MPEE at a concentration of 3.6 mg/mL. In addition, the cell viability test showed that none of the MPEEs had any cell toxicity up to a concentration of 250 µg/mL. The 60% MPEE exhibited higher in vitro and ex vivo antioxidant activities, possessed a protective capability for the biological membrane system, and can be used as a functional ingredient representing a potential source of natural antioxidants to prevent and treat oxidative stress-related disorders.


Assuntos
Antioxidantes/isolamento & purificação , Etanol/farmacologia , Flavonoides/farmacologia , Lamiaceae/efeitos dos fármacos , Fenóis/análise , Extratos Vegetais/farmacologia , Antioxidantes/química , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Flavonoides/química , Lamiaceae/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/química , Extratos Vegetais/química , Substâncias Protetoras/química , Substâncias Protetoras/isolamento & purificação , Substâncias Protetoras/farmacologia
7.
Food Chem ; 200: 55-61, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26830560

RESUMO

This study investigated the propylene glycol alginate (PGA)-induced coacervation of ß-conglycinin (7S), glycinin (11S) and isoflavones in heated soymilk. The addition of 0.9% PGA caused 7S, 11S, daidzein and genistein to coacervate following a 1h incubation period. SDS-PAGE showed that the protein bands corresponding to the 7S α', 7S α, 7S ß, 11S A3, and 11S acidic subunits and the 11S basic proteins in the soymilk supernatant fraction (SSF) decreased to 37.7 ± 12.7%, 24.7 ± 3.9%, 4.9 ± 1.8%, 8.5 ± 2.7%, 18.1 ± 1.8% and 6.0 ± 1.6%, respectively. In addition, isoflavones including daidzein and genistein were also coacervated from the SSF into the soymilk pellet fraction (SPF) following incubation with 0.9% PGA for 1h. The amounts of daidzein and genistein in the SSF decreased to 8.6 ± 1.6% and 2.0 ± 1.0%, respectively. HPLC analysis suggested that daidzein and genistein were bound to the 7S and 11S proteins. These results suggested that daidzein and genistein were co-precipitated with the 7S and 11S proteins into the SPF by 0.9% PGA. Our results demonstrated that PGA is a potent coagulant for the coacervation of 7S, 11S, daidzein and genistein.


Assuntos
Alginatos/química , Antígenos de Plantas/química , Cromatografia Líquida de Alta Pressão/métodos , Globulinas/química , Isoflavonas/química , Proteínas de Armazenamento de Sementes/química , Leite de Soja/química , Proteínas de Soja/química , Temperatura Alta
8.
Chem Commun (Camb) ; 50(46): 6116-9, 2014 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-24776788

RESUMO

We have synthesized and evaluated two self-immobilizing, turn-on fluorescent probes carrying a coumarin molecular framework for imaging intracellular human steroid sulfatase (STS) activity. The 8-fluoromethyl coumarin derivative, which gives stronger fluorescence response in the incubation study with STS preparations, was successfully applied to visualize STS activity in cells.


Assuntos
Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Esteril-Sulfatase/metabolismo , Linhagem Celular , Ativação Enzimática , Humanos , Estrutura Molecular , Esteril-Sulfatase/análise
9.
J Agric Food Chem ; 59(21): 11403-6, 2011 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-21967291

RESUMO

Hydrogen peroxide is commonly used in the food processing industry as a chlorine-free bleaching and sterilizing agent, but excessive amounts of residual hydrogen peroxide have led to cases of food poisoning. Here we describe the development of a novel nonenzymatic colorimetric method for the determination of residual hydrogen peroxide in foods and agricultural products. Nitrophenylboronic acids chemoselectively react with hydrogen peroxide under alkaline conditions to produce yellow nitrophenolates. Of the three nitrophenylboronic acid isomers tested, the p-isomer displayed the highest sensitivity for hydrogen peroxide and the fastest reaction kinetics. The reaction product, p-nitrophenolate, has an absorption maximum at 405 nm and a good linear correlation between the hydrogen peroxide concentration and the A(405) values was obtained. We successfully applied this convenient and rapid method for hydrogen peroxide determination to samples of dried bean curds and disposable chopsticks, thereby demonstrating its potential in foods and agricultural industries.


Assuntos
Ácidos Borônicos/química , Colorimetria/métodos , Análise de Alimentos/métodos , Conservantes de Alimentos/análise , Peróxido de Hidrogênio/análise , Sensibilidade e Especificidade
11.
J Biol Chem ; 286(20): 17736-45, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21454596

RESUMO

Bacterial polysaccharides are known to induce the immune response in macrophages. Here we isolated a novel extracellular polysaccharide from the biofilm of Thermus aquaticus YT-1 and evaluated its structure and immunomodulatory effects. The size of this polysaccharide, TA-1, was deduced by size-exclusion chromatography as 500 kDa. GC-MS, high performance anion-exchange chromatography with pulsed amperometric detection, electrospray ionization-MS/MS, and NMR revealed the novel structure of TA-1. The polysaccharide is composed of tetrasaccharide-repeating units of galactofuranose, galactopyranose, and N-acetylgalactosamine (1:1:2) and lacked acidic sugars. TA-1 stimulated macrophage cells to produce the cytokines TNF-α and IL-6. Screening of Toll-like receptors and antibody-blocking experiments indicated that the natural receptor of TA-1 in its immunoactivity is TLR2. Recognition of TA-1 by TLR2 was confirmed by TA-1 induction of IL-6 production in peritoneal macrophages from wild-type mice but not from TLR2(-/-) mice. TA-1, as a TLR2 agonist, could possibly be used as an adjuvant and could enhance cytokine release, which increases the immune response. Furthermore, TA-1 induced cytokine release is dependent on MyD88/TIRAP.


Assuntos
Biofilmes , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Polissacarídeos Bacterianos/imunologia , Thermus/fisiologia , Receptor 2 Toll-Like/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Configuração de Carboidratos , Células HEK293 , Humanos , Interleucina-6/genética , Interleucina-6/imunologia , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Polissacarídeos Bacterianos/farmacologia , Receptor 2 Toll-Like/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
12.
J Agric Food Chem ; 56(21): 9892-8, 2008 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-18841980

RESUMO

The bioactive polysaccharides (named ZPF1) from yam ( Dioscorea batatas) were chemically determined, suggesting repeating beta-1,4-mannan as mainly having a feature of acetylation on C2-OH and C3-OH, around 28%. The ZPF1 participated in the stimulation of murine wild-type macrophages predominantly in tumor necrosis factor-alpha (TNFalpha). Toll-like receptor 4 is proved to be one of the cellular receptors in ZPF1-mediated TNFalpha secretion. Reactive oxygen species transmission and PI3-kinase are found necessary for regulating TNFalpha secretion by ZPF1 stimulation. Moreover, we found that extracellular signal-regulated kinase 1/2, Jun N-terminal kinase 1/2, and p38 mitogen-activated protein kinase play important roles in the regulation of TNFalpha secretion in ZPF1-stimulated macrophages.


Assuntos
Dioscorea/química , Polissacarídeos/farmacologia , Proteínas Quinases/imunologia , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Linhagem Celular , Dioscorea/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química
14.
Chemistry ; 13(24): 6985-91, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17503417

RESUMO

Five new polyketides that contain tetramic acids, myceliothermophins A-E, were isolated from the thermophilic fungus Myceliophthora thermophila. Two sets of 5-alkyl-5-hydroxyl (or 5-methoxyl)-1H-pyrrol-2(5H)-one diastereomers, myceliothermophins A/B and C/D, were separated as pure compounds by using silica-gel column chromatography and recycling reverse-phase high-performance liquid chromatography (RP-HPLC). The relative configurations of the chiral centers in 5-alkyl-5-hydroxyl (or 5-methoxyl)-1H-pyrrol-2(5H)-one moieties were deduced from NOESY correlations. In the cytotoxic assay, the 5-(2-methylpropyldiene)-1H-pyrrol-2(5H)-one analogue (myceliothermophin E) exhibited inhibition against four cancer cell lines. In addition, the significant inhibitory effect of myceliothermophins A and C and the inactivity of myceliothermophins B and D revealed the importance of the relative configurations of 5-alkyl-5-hydroxyl (or 5-methoxyl)-1H-pyrrol-2(5H)-one moieties on their cytotoxicity potency against cancer cells.


Assuntos
Macrolídeos/química , Macrolídeos/toxicidade , Pirrolidinonas/química , Sordariales/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Macrolídeos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo
15.
Chem Phys Lipids ; 146(2): 85-93, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17274971

RESUMO

1,2-Ethylene-di-N-n-propylcarbamate (1) is characterized as an essential activator of Pseudomonas species lipase while 1,2-ethylene-di-N-n-butyl-, t-butyl-, n-heptyl-, and n-octyl-carbamates (2-5) are characterized as the pseudo substrate inhibitors of the enzyme in the presence of the detergent taurocholate or triton X-100. The inhibition and activation reactions are more sensitive in taurocholate than in triton X-100. From CD studies, the enzyme changes conformations in the presence of the detergent and further alters conformations by addition of the carbamate activator or inhibitor into the enzyme-detergent adduct. Therefore, this study suggests that the conformational change of lipase during interfacial activation is a continuous process to expose the active site of the enzyme to substrate. From 600 MHz (1)H NMR studies, the conformations of the alpha- and beta-methylene moieties of the activator 1,2-ethylene-di-N-n-propylcarbamate in the presence of substrate change after adding taurocholate into the mixture, and the conformations of the beta-methylene moieties of the inhibitor 1,2-ethylene-di-N-n-butylcarbamate in the presence of substrate alter after adding taurocholate into the mixture.


Assuntos
Carbamatos/farmacologia , Detergentes/química , Inibidores Enzimáticos/farmacologia , Lipase/antagonistas & inibidores , Lipase/metabolismo , Pseudomonas/enzimologia , Ativação Enzimática , Ressonância Magnética Nuclear Biomolecular
17.
J Biochem Mol Toxicol ; 19(4): 234-43, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16173062

RESUMO

Biphenyl-4-acyoxylate-4'-N-butylcarbamates 1-8 are synthesized from 4,4'-biphenol and are characterized as the pseudosubstrate inhibitors of acetylcholinesterase. In other words, the inhibitors bind to the enzyme and react with the enzyme to form the tetrahedral intermediates for the K(i) steps, and then the tetrahedral intermediates exclude the leaving groups to form a common N-butycarbamyl enzyme intermediate for the k(c) steps. Due to a linear character of the 4,4'-biphenyl moiety, the 4'-N-butylcarbamate moieties of the inhibitors react with the Ser200 residue of the enzyme while the 4-acyoxylate moieties of the inhibitors, on the other hand, should fit in the peripheral anionic site of the enzyme, which is located at the mouth of the deep active site gorge. Thus, carbamates with varied acyl substituents at the 4-position of the biphenyl ring are good candidates for probing the quantitative structure activity relationships for the peripheral anionic site of the enzyme. The fact that the pK(i), log k(c), and log K(i) values are correlated with neither the Taft substituent constant (sigma*) nor the Taft steric constant (E(s)) indicates that the 4-acyoxylate moieties of the inhibitors are too far away from the reaction center. However, the pK(i), log k(c), and log K(i) values are linearly correlated with the Hansch hydrophobicity constant, pi. The intensity constants (psi) for these correlations are 0.16, -0.035, and 0.13, respectively. These results indicate that interactions between the 4-acyoxylate groups of the inhibitors and the peripheral anionic site of the enzyme are mainly hydrophobic ones. The correlation results are slightly improved by using the two-parameter correlations with the Taft substituent steric constant, E(s), and pi. For pK(i), log k(c), and log K(i)-E(s)-pi correlations, the psi values are 0.21, -0.021, and 0.19, respectively; the intensity constants for steric effect (delta) are 0.08, 0.022, and 0.10, respectively. Besides hydrophobic interactions, the two-parameter correlations also suggest that little steric hindrance occurs for the bulkier inhibitors to pass by the peripheral anionic site of the enzyme.


Assuntos
Acetilcolinesterase/química , Carbamatos/química , Inibidores da Colinesterase/química , Relação Quantitativa Estrutura-Atividade , Sítios de Ligação , Humanos , Cinética , Modelos Químicos
18.
Eur J Biochem ; 271(22): 4545-51, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15560795

RESUMO

The polar glycolipids were isolated from the thermophilic bacteria Meiothermus taiwanensis ATCC BAA-400 by ethanol extraction and purified by Sephadex LH-20 and silica gel column chromatography. The fatty acid composition of O-acyl groups in the glycolipids was obtained by gas chromatography mass spectroscopy analysis on their methyl esters derived from methanolysis and was made mainly of C(15:0) (34.0%) and C(17:0) (42.3%) fatty acids, with the majority as branched fatty acids (over 80%). Removal of O-acyl groups under mild basic conditions provided two glycolipids, which differ only in N-acyl substitution on a hexosamine. Electrospray mass spectroscopy analysis revealed that one has a C(17:0) N-acyl group and the other hydroxy C(17:0) in a ratio of about 1 : 3.5. Furthermore, complete de-lipidation with strong base followed by selective N-acetylation resulted in a homogeneous tetraglycosyl glycerol. The linkages and configurations of the carbohydrate moiety were then elucidated by MS and various NMR analyses. Thus, the major glycolipid from M. taiwanensis ATCC BAA-400 was determined with the following structure: alpha-Galp(1-6)-beta-Galp(1-6)-beta-GalNAcyl(1,2)-alpha-Glc(1,1)-Gro diester, where N-acyl is C(17:0) or hydroxy C(17:0) fatty acid and the glycerol esters were mainly iso- and anteisobranched C(15:0) and C(17:0).


Assuntos
Deinococcus/química , Glicerídeos/química , Glicolipídeos/química , Acilação , Configuração de Carboidratos , Sequência de Carboidratos , Deinococcus/genética , Cromatografia Gasosa-Espectrometria de Massas , Éteres Metílicos/análise , Ressonância Magnética Nuclear Biomolecular , Espectrometria de Massas por Ionização por Electrospray
19.
Int J Syst Evol Microbiol ; 54(Pt 5): 1849-1855, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15388754

RESUMO

Two novel bacteria, with an optimum growth temperature of approximately 60 degrees C, were isolated from Lu-shan hot springs in the central region of Taiwan. These isolates were aerobic, thermophilic, halotolerant, pink-pigmented, heterotrophic and resistant to gamma-radiation. Both pleomorphic, short, rod-shaped cells and coccoid cells were observed. Strains LS-286 (= ATCC BAA-452 = BCRC 17198) and LS-293T (= ATCC BAA-406T = BCRC 17173T) represented a novel species of the genus Rubrobacter, according to a phylogenetic analysis of the 16S rRNA gene, DNA-DNA hybridization, biochemical features and fatty acid composition. The name Rubrobacter taiwanensis sp. nov. is proposed for this novel species, with LS-293T as the type strain.


Assuntos
Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Fontes Termais/microbiologia , Actinobacteria/fisiologia , Actinobacteria/efeitos da radiação , Aerobiose , Técnicas de Tipagem Bacteriana , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Ácidos Graxos/análise , Raios gama , Genes de RNAr/genética , Temperatura Alta , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Pigmentos Biológicos/biossíntese , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan , Temperatura , Microbiologia da Água
20.
Hunan Yi Ke Da Xue Xue Bao ; 28(4): 322-6, 2003 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-14653107

RESUMO

OBJECTIVE: To establish a competitive reverse transcription-polymerase chain reaction (RT-PCR) assay to quantify the expression of glycosylphosphatidylinositol specific phospholipase D (GPI-PLD) gene. METHODS: A competitive GPI-PLD cDNA fragment was constructed by site-directed mutagenesis by PCR method. The competitive cDNA fragment had the same primer binding sites as the target cDNA, but was 20 bp shorter in length. The competitive cDNA was transcripted into the competitive RNA in vitro as the internal standard. Then the competitive RNA was reversely transcripted and amplified together with total RNA extracted from K562 cells. The two amplified cDNA fragments could be distinguished by 10% polyacrylamide gel electrophoresis. The concentration of cellular GPI-PLD mRNA was derived from the ratio between the intensities of the bands corresponding to the amplified products. RESULTS: A 198 bp GPI-PLD competitive RNA was constructed and prepared. The competitive RNA could compete well with the target RNA in the RT-PCR reaction. The expression of GPI-PLD gene in K562 cells was (440 +/- 20) copies/ng. CONCLUSION: A competitive RT-PCR assay for the quantification of GPI-PLD gene expression may be established successfully. This method is highly sensitive, specific, and accurate.


Assuntos
Glicosilfosfatidilinositóis/genética , Fosfolipase D/genética , Regulação Neoplásica da Expressão Gênica , Glicosilfosfatidilinositóis/biossíntese , Humanos , Células K562 , Mutagênese Sítio-Dirigida , Fosfolipase D/biossíntese , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA