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1.
Cancer Control ; 28: 1073274821989320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33517745

RESUMO

BACKGROUND: Data about the risk factors and pancreatic cancer in developing countries remain limited. We investigated for the first time the role of a number of risk factors (family cancer history, smoking, alcohol consumption, diabetes, inflammation disease, HBV infection) associated with pancreatic cancer among Vietnamese patients. METHODS: We included all patients hospitalized at 4 Northern Vietnamese hospitals (Vietnam National Cancer Hospital, Bach Mai, Viet Duc, Thai Nguyen) and diagnosed with pancreatic cancer during the period from 2017 to 2019. Risk factors of eligible patients were collected and assessed the associations using a matched control study and logistic regression model analysis. RESULTS: We identified 196 patients with diagnosis of pancreatic cancer of which 114 males and 82 females. The average age of the patient at the time of diagnosis was 58.28 years (standard deviation of 12.94, ranging from 25 to 87). Most of patients were diagnosed at advanced stage (85%). Smoking, diabetes, inflammation disease significantly increased the cancer risks (OR and 95% CI were 2.42 (1.38-4.37), 3.09 (1.54-6.68), 2.21 (1.42-3.45), respectively). HBV infection demonstrated a significant link with pancreatic cancer in univariate model (OR = 2.94 (1.08-9.36)), but not in multivariate model. However, cancer family history and alcohol drinkers did not show any significantly increased risk related to pancreatic cancer. CONCLUSIONS: Our finding showed smoking, diabetes, inflammation disease significantly increased the risk of pancreatic cancer in Vietnam.


Assuntos
Complicações do Diabetes , Neoplasias Pancreáticas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/efeitos adversos , Estudos de Casos e Controles , Países em Desenvolvimento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/etiologia , Fatores de Risco , Fumar/efeitos adversos , Vietnã
2.
Pediatr Int ; 62(7): 828-833, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32048368

RESUMO

BACKGROUND: The aim of this study was to assess the efficacy of our simple landmark technique for laparoscopic detorsion and the Ladd's procedure (lap-Ladd) for malrotation with midgut volvulus in neonates and to identify the risk factors for reoperation after the lap-Ladd. METHODS: We conducted a retrospective chart review of 42 patients after lap-Ladd for malrotation between April 2017 and June 2019. Information regarding patient status and intraoperative and postoperative data were analyzed. RESULTS: Thirty-one patients had volvulus (73.8 %), while 11 patients did not (26.2%). The median age and weight between the two groups at operation were 9 days (range, 3-28 days), 3.2 kg (range, 2-8 kg) and 6 days (range, 2-11), 2.9 kg (range, 2-3.8 kg), respectively. The operative time was significantly shorter in patients with volvulus compared to those without (60 vs 105 min, P = 0.002). Two cases were converted to open surgery because of ischemic changes of the total small intestine during surgery. Reoperation was required in two patients with volvulus (due to adhesive small bowel obstruction and recurrent volvulus). There was no significant predictive factor for reoperation after the lap-Ladd procedure. CONCLUSION: Our simple landmark lap-Ladd procedure demonstrated feasibility and good short-term outcomes in neonates with malrotation, regardless of the presence or absence of volvulus.


Assuntos
Anormalidades do Sistema Digestório/cirurgia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Volvo Intestinal/cirurgia , Laparoscopia/métodos , Feminino , Humanos , Recém-Nascido , Obstrução Intestinal/epidemiologia , Intestino Delgado/patologia , Masculino , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
3.
Pediatr Surg Int ; 35(11): 1211-1216, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31270674

RESUMO

PURPOSE: We aimed to describe our robotic-assisted surgery (RAS) techniques and assess the early results of RAS for choledochal cysts in children. METHODS: We conducted a retrospective chart review of children who underwent RAS for a congenital choledochal cyst at our institution between February 2013 and August 2016. We analyzed patient characteristics, operative data, and postoperative outcomes. RESULTS: Thirty-nine patients underwent RAS for a choledochal cyst (female 30). The operation was performed with four robotic ports and one laparoscopic port for the assistant. The Roux loop was fashioned extracorporeally. Twenty patients (51.3%) had a Todani Type I cyst and the others had Type IV. The mean patient age and weight and choledochal cyst diameter at the time of the operation were 40.2 months (range 5-108 months), 13.4 kg (range 6.5-29 kg), and 27.2 mm (range 9-112 mm), respectively. The mean operating time was 192.7 min (range 150-330 min). There were no intraoperative complications; no conversions to laparoscopic or open surgery; and no postoperative complications, including cholangitis, cholelithiasis, or anastomotic stenosis. CONCLUSION: Pediatric RAS CC resection is safe and feasible. The robot-assisted technique overcame technical difficulties. However, in pediatric cases, a skilled robotic surgical team and procedural modifications are needed.


Assuntos
Cisto do Colédoco/cirurgia , Procedimentos Cirúrgicos Robóticos , Criança , Pré-Escolar , Feminino , Hospitais Pediátricos , Humanos , Lactente , Masculino , Duração da Cirurgia , Estudos Retrospectivos , Vietnã
4.
Bioorg Med Chem Lett ; 27(17): 4007-4010, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28797798

RESUMO

Mass-guided isolation of the dichloromethane/methanol extracts from a specimen of teleomorphic fungus of the family Cortinariaceae resulted in the identification of a new dimeric cyclobutane metabolite, achyrodimer F (1), along with the monomers hispidin (2) and bisnoryangonin (3). Their structures were determined by NMR and MS data analyses. Density Function Theory (DFT) NMR calculations was employed to confirm the chemical structure of achyrodimer F. Compound 1 inhibited tyrosyl-DNA phosphodiesterase I with an IC50 value of 1µM.


Assuntos
Agaricales/química , Ciclobutanos/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Pironas/farmacologia , Austrália , Ciclobutanos/química , Ciclobutanos/isolamento & purificação , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Inibidores de Fosfodiesterase/química , Inibidores de Fosfodiesterase/isolamento & purificação , Pironas/química , Pironas/isolamento & purificação , Relação Estrutura-Atividade
5.
Phys Rev Lett ; 117(8): 085503, 2016 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-27588866

RESUMO

We experimentally demonstrate the enhancement of the spontaneous emission rate of GaAs quantum wells embedded in rolled-up metamaterials. We fabricate microtubes whose walls consist of alternating Ag and (In)(Al)GaAs layers with incorporated active GaAs quantum-well structures. By variation of the layer thickness ratio of the Ag and (In)(Al)GaAs layers we control the effective permittivity tensor of the metamaterial according to an effective medium approach. Thereby, we can design samples with elliptic or hyperbolic dispersion. Time-resolved low temperature photoluminescence spectroscopy supported by finite-difference time-domain simulations reveal a decrease of the quantum well's spontaneous emission lifetime in our metamaterials as a signature of the crossover from elliptic to hyperbolic dispersion.

6.
Biochemistry ; 54(3): 909-31, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25540822

RESUMO

The rate at which genome sequencing data is accruing demands enhanced methods for functional annotation and metabolism discovery. Solute binding proteins (SBPs) facilitate the transport of the first reactant in a metabolic pathway, thereby constraining the regions of chemical space and the chemistries that must be considered for pathway reconstruction. We describe high-throughput protein production and differential scanning fluorimetry platforms, which enabled the screening of 158 SBPs against a 189 component library specifically tailored for this class of proteins. Like all screening efforts, this approach is limited by the practical constraints imposed by construction of the library, i.e., we can study only those metabolites that are known to exist and which can be made in sufficient quantities for experimentation. To move beyond these inherent limitations, we illustrate the promise of crystallographic- and mass spectrometric-based approaches for the unbiased use of entire metabolomes as screening libraries. Together, our approaches identified 40 new SBP ligands, generated experiment-based annotations for 2084 SBPs in 71 isofunctional clusters, and defined numerous metabolic pathways, including novel catabolic pathways for the utilization of ethanolamine as sole nitrogen source and the use of d-Ala-d-Ala as sole carbon source. These efforts begin to define an integrated strategy for realizing the full value of amassing genome sequence data.


Assuntos
Proteínas de Transporte/metabolismo , Redes e Vias Metabólicas , Metaboloma , Metabolômica/métodos , Anotação de Sequência Molecular , Bacillus/metabolismo , Carboidratos/química , Clonagem Molecular , Cristalografia por Raios X , Fluorometria , Cinética , Ligantes , Reprodutibilidade dos Testes , Homologia de Sequência de Aminoácidos
7.
In Vivo ; 38(2): 963-970, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38418140

RESUMO

BACKGROUND/AIM: Knee osteoarthritis (KOA) is the most common disease in adults. We conducted a clinical study to evaluate the efficacy and safety of Bach Nien Kien (BNK) in supportive therapy for patients with symptomatic KOA. PATIENTS AND METHODS: An open interventional study was performed on 60 patients aged 38 to 70 with the diagnosis of symptomatic KOA. The patients were assigned to a study group (SG) with 30 subjects and a control group (CG) with 30 subjects using a matching method. The patients in SG were treated with electroacupuncture, glucosamine supplement, and BNK, while the patients in CG received the same treatment without BNK. RESULTS: At the end of the 30-day treatment (d30), the SG had a reduction in VAS score compared to a pre-treatment level of 3.03±0.96 points, which was more than the CG of 2.5±0.90 points. The excellent result in the SG was 10%, and the CG had no excellent result. The good result in the SG was 56.7%, and the CG group was only 26.7%. The moderate and poor results in the CG were high, 63.3%, and 10%, respectively; in the SG, only 26.7% and 6.7%. The difference in overall treatment results between the SG and CG was statistically significant (p<0.05). During the 30-day treatment period in both groups, no patient reported any undesirable effects. CONCLUSION: Bach Nien Kien health supplement is effective and safe for controlling KOA symptoms and improving joint motion and quality of life for patients with symptomatic KOA.


Assuntos
Eletroacupuntura , Osteoartrite do Joelho , Adulto , Humanos , Osteoartrite do Joelho/terapia , Osteoartrite do Joelho/tratamento farmacológico , Qualidade de Vida , Resultado do Tratamento , Medição da Dor
8.
Int J Syst Evol Microbiol ; 63(Pt 8): 3075-3078, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23416572

RESUMO

The taxonomic properties of strain DC2c-G4(T), a Gram-staining-negative, ovoid, gellan-gum-degrading bacterial isolate, were examined. Phylogenetic analysis based on 16S rRNA gene sequences identified this isolate as a member of the phylum Verrucomicrobia and closest to the genus Prosthecobacter. The 16S rRNA gene sequence similarities between this isolate and any of the type strains of species of the genus Prosthecobacter were less than 95 %. In addition, the absence of a single prostheca and the predominant menaquinone MK-7(H2) supported the differentiation of this isolate from the genus Prosthecobacter. Here, we propose Brevifollis gellanilyticus gen. nov., sp. nov. to accommodate the isolate. The type strain of the type species is DC2c-G4(T) (= NBRC 108608(T) = CIP 110457(T)).


Assuntos
Filogenia , Polissacarídeos Bacterianos/metabolismo , Verrucomicrobia/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Verrucomicrobia/genética , Verrucomicrobia/isolamento & purificação , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
9.
J Med Food ; 26(4): 262-269, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37071614

RESUMO

This study aims to assess the effectiveness and safety of plant-derived food supplement Ich Nieu Khang (INK) as a dietary supplement for overactive bladder (OAB) symptoms. A total of 50 patients 18-80 years of age with the diagnosis and symptoms of the OAB were enrolled in the study and followed up for 30 days. The INK treatment efficacy, in terms of changes in nocturnal and day-time urination frequency, urination incontinence episodes, level of OAB symptoms according to Homma's OABSS scale, sleep quality according to Pittsburg Sleep Quality Index (PSQI), and possible side effects of the INK phytotherapy, was evaluated. INK significantly improved all OAB symptoms scores with a reduction of average nocturia from 4.06 ± 1.53 to 1.14 ± 0.94, the daily average urination urgency from 7.67 ± 5.00 to 5. 82 ± 3.70, the daily average frequency of urination from 9.96 ± 4.04 to 8.00 ± 3.70, weekly average incontinence of urination from 0.92 ± 1.56 to 0.60 ± 1.02, and OABSS Homma's score decreased from 9.31 ± 1.44 to 6.8 ± 2.21. INK phytotherapy also resulted in sleep quality improvement by PSQI score decreasing from 13.11 ± 1.33 to 10.54 ± 2.21. There were no adverse effects and abnormalities in paraclinical parameters with INK therapy. The results of our study suggest that INK dietary supplement is effective and safe phytotherapy for patients with primary OAB symptoms within 30 days of treatment. Larger control clinical trials are warranted to confirm our findings and promote wider use of INK for OAB and possible other age-related urination disorders.


Assuntos
Bexiga Urinária Hiperativa , Humanos , Lactente , Bexiga Urinária Hiperativa/tratamento farmacológico , Bexiga Urinária Hiperativa/diagnóstico , Micção , Resultado do Tratamento , Sono , Qualidade de Vida
10.
Curr Org Synth ; 20(8): 880-889, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36856172

RESUMO

AIMS: Synthesis of 1,4-Dihydropyridines (1,4-DHP) using heterogeneous catalyst under mild condition. OBJECTIVE: Our objective is to explore new applications of non-metal heterogeneous catalysts in the synthesis of 1,4-DHP derivatives in a greener and more efficient approach. METHODS: A greener and more efficient method for the synthesis of 1,4-DHPs and an asymmetric 1,4-DHP (Felodipine drug) was successfully developed in high yields using a heterogeneous SBA- 15-SO3H catalyst. RESULTS: A series of symmetric 1,4-DHP and an asymmetric 1,4-DHP (Felodipine drug) were successfully prepared in high yields using a heterogeneous SBA-15-SO3H catalyst. CONCLUSION: The catalyst, SBA-15-SO3H, exhibited an efficient catalyst activity for the synthesis of 1,4-DHP derivatives in high yields from the aldehyde, ß-ketoester, and NH4OAc as a nitrogen source under mild conditions and short reaction time. Bronsted acid sites of this solid catalyst were figured out to play a key role in this transformation. Interestingly, our catalyst is air-stable and can be recycled at least 5 times without losing catalytic activity.

11.
J Nat Prod ; 75(12): 2200-8, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23215348

RESUMO

Three new cyclic depsipeptides, neamphamides B (2), C (3), and D (4), were isolated from the Australian sponge Neamphius huxleyi. The planar structural characterization of these molecules was elucidated using 2D NMR experiments and ESI-FTICR-MS(n). Their configurations were determined by Marfey's method and J-based NMR analysis. These new metabolites inhibited the growth of human cell lines (A549, HeLa, LNCaP, PC3, and NFF) with IC(50) values ranging from 88 to 370 nM. However, neamphamide D causes A549 cell proliferation at subcytotoxic doses and should be treated cautiously as a cytotoxic compound.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Depsipeptídeos/isolamento & purificação , Depsipeptídeos/farmacologia , Poríferos/química , Animais , Antineoplásicos/química , Austrália , Depsipeptídeos/química , Células HeLa , Humanos , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular
12.
Planta Med ; 78(7): 730-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22354391

RESUMO

A new glucoalkaloid, vespertilioside, together with three known alkaloids, including 11- ß-methoxyglucoerysovine, erysotrine, and hypaphorine, were isolated from the fruits of E. vespertilio Benth. In addition, three known isoflavonoids, including phaseollin, alpiniumisoflavone, and phaseollidin, were identified from the plant stems. The structures of compounds were determined by 1D/2D NMR and mass experiments. The cytotoxic activity of all compounds was evaluated against a metastatic prostate cancer cell line (PC3) and neonatal foreskin fibroblast (NFF) using a real-time label-free cell analyser. Among the tested compounds, phaseollidin showed cytotoxic activities against PC3 (IC (50) = 8.83 ± 1.87 µM) and NFF (0.64 ± 0.37 µM) cell lines.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Citotoxinas/isolamento & purificação , Erythrina/química , Isoflavonas/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Pterocarpanos/farmacologia , Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Austrália , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citotoxinas/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Flavonoides/isolamento & purificação , Prepúcio do Pênis/citologia , Frutas/química , Humanos , Recém-Nascido , Concentração Inibidora 50 , Isoflavonas/química , Isoflavonas/isolamento & purificação , Masculino , Casca de Planta/química , Caules de Planta/química , Pterocarpanos/química , Pterocarpanos/isolamento & purificação , Sementes/química , Relação Estrutura-Atividade
13.
Adv Respir Med ; 90(6): 500-510, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36547011

RESUMO

Introduction: Despite the theoretical importance of serum immunoglobulin (Ig) in the outcome of COPD exacerbations, the existing evidence for this has not been enough. This study was performed to evaluate changes in serum Ig levels and their relationship with outcomes of acute infectious exacerbations in patients with COPD. Methods: The prospective study was conducted at Military Hospital 103 from August 2017 to April 2019. Group D patients with COPD with infectious exacerbation were selected for participation in the study. The control group consisted of 30 healthy people. The patients were provided clinical examination and laboratory service; simultaneously, we measured their serum Ig levels (total IgG, IgG1, IgG2, IgG3, IgG4) at two time points: at admission (T1) and the final health outcome (T2). Results: The median levels of total IgG in patients at times T1 and T2 were significantly lower compared with those in the healthy group (1119.3 mg/dL and 1150.6 mg/dL compared with 2032.2 mg/dL) (p < 0.001). Regarding changes among IgG subclasses, the IgG1, IgG3, and IgG4 levels measured at T1 and T2 were reduced significantly compared with the control group (p < 0.05); the IgG3 levels at T1 were significantly higher than those at T2. IgG3 levels in patients with life-threatening exacerbations were significantly lower than the remaining ones (24.6 (26.8−155.5) mg/dL and 25.6 (29.5−161.2) mg/dL, respectively, p = 0.023). Conclusions: In group D patients with COPD with infectious exacerbations, there was a decrease in the serum IgG, IgG1, IgG3, and IgG4 levels. IgG3 levels were associated with the severity of COPD exacerbation.


Assuntos
Imunoglobulina G , Doença Pulmonar Obstrutiva Crônica , Humanos , Estudos Prospectivos
14.
J Am Chem Soc ; 133(45): 18452-62, 2011 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21958118

RESUMO

Carbonic anhydrases (CAs) are enzymes whose endogenous reaction is the reversible hydration of CO(2) to give HCO(3)(-) and a proton. CA are also known to exhibit weak and promiscuous esterase activity toward activated esters. Here, we report a series of findings obtained with a set of CA inhibitors that showed quite unexpectedly that the compounds were both inhibitors of CO(2) hydration and substrates for the esterase activity of CA. The compounds comprised a monosaccharide core with the C-6 primary hydroxyl group derivatized as a sulfamate (for CA recognition). The remaining four sugar hydroxyl groups were acylated. Using protein X-ray crystallography, the crystal structures of human CA II in complex with four of the sulfamate inhibitors were obtained. As expected, the four structures displayed the canonical CA protein-sulfamate interactions. Unexpectedly, a free hydroxyl group was observed at the anomeric center (C-1) rather than the parent C-1 acyl group. In addition, this hydroxyl group is observed axial to the carbohydrate ring while in the parent structure it is equatorial. A mechanism is proposed that accounts for this inversion of stereochemistry. For three of the inhibitors, the acyl groups at C-2 or at C-2 and C-3 were also absent with hydroxyl groups observed in their place and retention of stereochemistry. With the use of electrospray ionization-Fourier transform ion cyclotron resonance-mass spectrometry (ESI-FTICR-MS), we observed directly the sequential loss of all four acyl groups from one of the carbohydrate-based sulfamates. For this compound, the inhibitor and substrate binding mode were further analyzed using free energy calculations. These calculations suggested that the parent compound binds almost exclusively as a substrate. To conclude, we have demonstrated that acylated carbohydrate-based sulfamates are simultaneously inhibitor and substrate of human CA II. Our results suggest that, initially, the substrate binding mode dominates, but following hydrolysis, the ligand can also bind as a pure inhibitor thereby competing with the substrate binding mode.


Assuntos
Carboidratos/química , Anidrase Carbônica II/antagonistas & inibidores , Inibidores da Anidrase Carbônica/farmacologia , Ésteres/química , Ácidos Sulfônicos/farmacologia , Anidrase Carbônica II/metabolismo , Inibidores da Anidrase Carbônica/química , Humanos , Hidrólise , Modelos Moleculares , Conformação Molecular , Relação Estrutura-Atividade , Ácidos Sulfônicos/química
15.
Biochem J ; 431(1): 51-61, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20642456

RESUMO

CNS (central nervous system) adrenaline (epinephrine) is implicated in a wide range of physiological and pathological conditions. PNMT (phenylethanolamine N-methyltransferase) catalyses the final step in the biosynthesis of adrenaline, the conversion of noradrenaline (norepinephrine) to adrenaline by methylation. To help elucidate the role of CNS adrenaline, and to develop potential drug leads, potent, selective and CNS-active inhibitors are required. The fragment screening approach has advantages over other lead discovery methods including high hit rates, more efficient hits and the ability to sample chemical diversity more easily. In the present study we applied fragment-based screening approaches to the enzyme PNMT. We used crystallography as the primary screen and identified 12 hits from a small commercial library of 384 drug-like fragments. The hits include nine chemicals with two fused rings and three single-ring chemical systems. Eight of the hits come from three chemical classes: benzimidazoles (a known class of PNMT inhibitor), purines and quinolines. Nine of the hits have measurable binding affinities (~5-700 µM) as determined by isothermal titration calorimetry and all nine have ligand efficiencies of 0.39 kcal/mol per heavy atom or better (1 kcal≈4.184 kJ). We synthesized five elaborated benzimidazole compounds and characterized their binding to PNMT, showing for the first time how this class of inhibitors interact with the noradrenaline-binding site. Finally, we performed a pilot study with PNMT for fragment-based screening by MS showing that this approach could be used as a fast and efficient first-pass screening method prior to characterization of binding mode and affinity of hits.


Assuntos
Inibidores Enzimáticos/química , Feniletanolamina N-Metiltransferase/antagonistas & inibidores , Feniletanolamina N-Metiltransferase/química , Benzimidazóis/química , Sítios de Ligação , Calorimetria , Cristalografia por Raios X , Cinética , Ligantes , Espectrometria de Massas , Modelos Moleculares , Feniletanolamina N-Metiltransferase/metabolismo
16.
J Am Chem Soc ; 131(8): 3057-62, 2009 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-19206230

RESUMO

The X-ray crystal structure of the adduct between the zinc metalloenzyme carbonic anhydrase II (CA, EC 4.2.1.1) with the recently discovered natural product coumarin derivative 6-(1S-hydroxy-3-methylbutyl)-7-methoxy-2H-chromen-2-one showed the coumarin hydrolysis product, a cis-2-hydroxy-cinnamic acid derivative, and not the parent coumarin, bound within the enzyme active site. The bound inhibitor exhibits an extended, two-arm conformation that effectively plugs the entrance to the enzyme active site with no interactions with the catalytically crucial zinc ion. The inhibitor is sandwiched between Phe131, with which it makes an edge-to-face stacking, and Asn67/Glu238sym, with which it makes several polar and hydrogen bonding interactions. This unusual binding mode, with no interactions between the inhibitor molecule and the active site metal ion is previously unobserved for this enzyme class and presents a new opportunity for future drug design campaigns to target a mode of inhibition that differs substantially from classical inhibitors such as the clinically used sulfonamides and sulfamates. Several structurally simple coumarin scaffolds were also shown to inhibit all 13 catalytically active mammalian CA isoforms, with inhibition constants ranging from nanomolar to millimolar. The inhibition is time dependent, with maximum inhibition being observed after 6 h.


Assuntos
Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/química , Cumarínicos/química , Cumarínicos/farmacologia , Anidrases Carbônicas/metabolismo , Cristalografia por Raios X , Isoenzimas , Espectrometria de Massas , Modelos Moleculares , Zinco/química
17.
J Biomol Screen ; 13(4): 265-75, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18349420

RESUMO

The authors describe first a proof-of-concept experiment to show direct affinity screening using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) is a rapid and informative approach for natural product extract screening. The study used 10 alkaloid-enriched plant extracts and 8 desalted marine extracts spiked with specific inhibitors of bovine carbonic anhydrase II (bCAII; EC4.2.1.1) as a model set. The spiked extracts were incubated with bCAII and then analyzed by ESI-FTICR-MS. The noncovalent complexes were detected, and the specific inhibitors were reidentified in the spiked natural product extracts. There was no interference from the desalted/alkaloid-enriched extracts to the formation of the noncovalent complexes. The method allowed quick identification of the molecular mass of the bound ligand. The authors then applied the screening to identify active compounds in natural product extracts. They employed direct infusion and online size exclusion chromatography (SEC) ESI-FTICR-MS to detect intact target-ligand complex. Eighty-five methanolic plant extracts were screened against bCAII by direct infusion ESI-FTICR-MS and by online SEC-ESI-FTICR-MS. One noncovalent complex was identified from the same plant extract by both methods. The molecular weight of the bound ligand from this extract was determined. Mass-directed purification gave 6-(1S-hydroxy-3-methylbutyl)-7-methoxy-2H-chromen-2-one (1) as the active compound. Subsequently, the binding to bCAII was confirmed by ESI-FTICR-MS. The binding specificity was determined by competition experiments between 1 and furosemide, a specific ligand of bCAII.


Assuntos
Produtos Biológicos/análise , Produtos Biológicos/química , Extratos Vegetais/análise , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Animais , Soluções Tampão , Anidrase Carbônica II/antagonistas & inibidores , Anidrase Carbônica II/química , Bovinos , Cromatografia em Gel , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Cinética , Ligantes , Espectroscopia de Ressonância Magnética , Peso Molecular , Rutaceae/química
18.
ACS Infect Dis ; 4(4): 431-444, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29436819

RESUMO

Natural products are well known for their biological relevance, high degree of three-dimensionality, and access to areas of largely unexplored chemical space. To shape our understanding of the interaction between natural products and protein targets in the postgenomic era, we have used native mass spectrometry to investigate 62 potential protein targets for malaria using a natural-product-based fragment library. We reveal here 96 low-molecular-weight natural products identified as binding partners of 32 of the putative malarial targets. Seventy-nine (79) fragments have direct growth inhibition on Plasmodium falciparum at concentrations that are promising for the development of fragment hits against these protein targets. This adds a fragment library to the published HTS active libraries in the public domain.


Assuntos
Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Espectrometria de Massas/métodos , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Ligação Proteica , Proteínas de Protozoários/metabolismo
19.
J Biomol Screen ; 21(2): 194-200, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26773071

RESUMO

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS or ESI-FTMS) was used to screen 192 natural product extracts and a 659-member natural product-based fragment library for bindings to a potential malaria drug target, Plasmodium falciparum Rab11a (PfRab11a, PF13_0119). One natural product extract and 11 fragments showed binding activity. A new natural product, arborside E, was identified from the active extract of Psydrax montigena as a weak binder. Its binding activity and inhibitory activity against PfRab11a were confirmed by ESI-FTMS titration experiments and an orthogonal enzyme assay.


Assuntos
Produtos Biológicos/química , Extratos Vegetais/química , Plantas/química , Espectrometria de Massas por Ionização por Electrospray/métodos
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