RESUMEN
The metabolic fate of anthocyanins until recently was relatively unknown, primarily as a result of their instability at physiological pH and a lack of published methods for isolating and identifying their metabolites from biological samples. The aim of the present work was to establish methods for the extraction and quantification of anthocyanin metabolites present in urine, serum, and fecal samples. 35 commercial and 10 synthetic analytes, including both known and predicted human and microbial metabolites of anthocyanins, were obtained as reference standards. HPLC and MS/MS conditions were optimized for organic modifier, ionic modifier, mobile phase gradient, flow rate, column type, MS source, and compound dependent parameters. The impact of sorbent, solvent, acid, preservative, elution, and evaporation on solid phase extraction (SPE) efficiency was also explored. The HPLC-MS/MS method validation demonstrated acceptable linearity (R(2), 0.997 ± 0.002) and sensitivity (limits of detection (LODs): urine, 100 ± 375 nM; serum, 104 ± 358 nM; feces 138 ± 344 nM), and the final SPE methods provided recoveries of 88.3 ± 17.8% for urine, 86.5 ± 11.1% for serum, and 80.6 ± 20.9% for feces. The final methods were applied to clinical samples derived from an anthocyanin intervention study, where 36 of the 45 modeled metabolites were detected within urine, plasma, or fecal samples. The described methods provide suitable versatility for the identification and quantification of an extensive series of anthocyanin metabolites for use in future clinical studies exploring absorption, distribution, metabolism, and elimination.
Asunto(s)
Antocianinas/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masas en TándemRESUMEN
A series of analogues of the non-steroidal anti-inflammatory drug (NSAID) sulindac 1 were synthesised tethered to nitric oxide (NO) donating functional groups. Sulindac shows antiproliterative effects against immortal PC3 cell lines. It was previously demonstrated that the effect can be enhanced when tethered to NO releasing groups such as nitrate esters, furoxans and sydnonimines. To explore this approach further, a total of fifty-six sulindac-NO analogues were prepared and they were evaluated as NO-releasing cytotoxic agents against prostate cancer (PCa) cell lines. Compounds 1k and 1n exhibited significant cytotoxic with IC50 values of 6.1±4.1 and 12.1±3.2µM, respectively, coupled with observed nitric oxide release.
Asunto(s)
Antineoplásicos/farmacología , Óxido Nítrico/química , Neoplasias de la Próstata/tratamiento farmacológico , Sulindac/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Masculino , Estructura Molecular , Neoplasias de la Próstata/patología , Relación Estructura-Actividad , Sulindac/síntesis química , Sulindac/químicaRESUMEN
The incorporation of furoxan and sydnonimine ring systems into amino acid side chains is demonstrated with the preparation of four novel amino acids which carry these nitric oxide-releasing motifs. N-((4-Nitrophenoxy)carbonyl)-3-phenylsydnonimine 9 and bis(phenylsulfonyl)furoxan 10 are the key intermediates for introducing the heterocycle side chains onto appropriate amine and alcohol functionalities respectively. Furoxan 5 and 7 both displayed NO release based on determination of nitrite production. Orthogonal amino acid protecting group strategies were deployed to demonstrate that the amino acids could be incorporated into peptide frameworks. By way of demonstration the amino acids were placed centrally into several tripeptide motifs. Griess test assays showed that these amino acids released NO in the presence of γ-glutathione (GST).
Asunto(s)
Aminoácidos/química , Aminoácidos/síntesis química , Carbamatos/química , Óxido Nítrico/química , Oxadiazoles/química , Péptidos/química , Péptidos/síntesis química , Técnicas de Química SintéticaRESUMEN
An efficient and high-yielding synthesis for [1,3,5-(13)C(3)]gallic acid from non-aromatic precursors is presented. [3,5-(13)C(2)]4H-Pyran-4-one was first prepared from the reaction between triethyl orthoformate and [1,3-(13)C(2)]acetone. The third (13)C-atom was introduced into the ring by reaction of the pyranone with diethyl [2-(13)C]malonate. The resulting ethyl 4-hydroxy-[1,3,5-(13)C(3)]benzoate was brominated in the 3- and 5-positions to give ethyl 3,5-dibromo-4-hydroxy-[1,3,5-(13)C(3)]benzoate. Subsequent hydrolysis of the ester and substitution of the bromine atoms with hydroxyl groups was achieved under basic conditions in a single step to yield the desired [1,3,5-(13)C(3)]gallic acid. The synthesis of [2,6-(13)C(2)]4H-pyran-4-one is also presented to demonstrate the potential of the methodology for the regioselective placement of (13)C-atoms into benzene rings.
Asunto(s)
Ácido Gálico/síntesis química , Marcaje Isotópico/métodos , Benceno , Isótopos de CarbonoRESUMEN
Better knowledge of the bioavailability and metabolism of isoflavones in prostate tissue is needed to further investigate their mechanisms of action in the context of prostate cancer prevention. A total of 12 men with benign prostatic hyperplasia received soy extract supplementation (3 Evestrel capsules, providing a total of 112.5 mg isoflavones aglycone eq/day) for 3 days before prostate surgery. Blood and prostate tissues were sampled and metabolites were identified using electrospray ionization liquid chromatography tandem mass spectrometry (LC-ESI-MS/MS) and chemically synthesized standards of glucuronidated isoflavones. The main metabolites were the same in prostate tissue and in plasma, namely, 2 monoglucuronides of daidzein and 2 monoglucuronides of genistein. Concentrations of total isoflavones measured in prostate reached 1.05 +/- 0.62 nmol/g tissue (range 0.30-2.23) at the time of sampling, 12 h after the last isoflavone supplementation. At that time point, prostate concentrations were lower than plasma concentrations in all volunteers: 0.47 nmol/g vs. 0.66 microM for daidzein and 0.58 nmol/g vs. 0.78 microM for genistein. Isoflavone mechanisms of action should thus be investigated in in vitro cell studies using physiological conditions, intracellular concentrations below 5 nmol/g and no intracellular deconjugation of the monoglucuronide metabolites.
Asunto(s)
Glucurónidos/análisis , Glucurónidos/metabolismo , Isoflavonas/administración & dosificación , Isoflavonas/farmacocinética , Próstata/química , Anciano , Cromatografía Líquida de Alta Presión , Dieta , Suplementos Dietéticos , Genisteína/análisis , Genisteína/sangre , Humanos , Isoflavonas/análisis , Isoflavonas/sangre , Masculino , Persona de Mediana Edad , Hiperplasia Prostática/metabolismo , Hiperplasia Prostática/cirugía , Neoplasias de la Próstata/prevención & control , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en TándemRESUMEN
The structure of the title compound, C(16)H(15)ClO(4), contains aryl rings which are inclined by 75.6â (1)° to each other. It displays intra-molecular O-Hâ¯O hydrogen bonding between the 2-hydr-oxy and carbonyl groups, forming a six-membered ring. Furthermore, the 4-hydr-oxy group, acting as a hydrogen-bond donor, is bound to the O atom of the 2-hydr-oxy group of another mol-ecule.
RESUMEN
Plant lignans are currently being widely studied for their potential benefits for human health as their consumption has been correlated with lower risks for developing chronic diseases, such as breast cancer and coronary heart disease. However, studies of some classes of lignans, in particular the furofurans, are hampered by the lack of suitable standards to allow accurate analysis. Herein, we report the syntheses of two racemic (13)C-labeled furofuran lignans [7,8,9-(13)C(3)]medioresinol and [7,8,9-(13)C(3)]sesamin as internal standards for LC-MS analysis. The labeled furofuran lignans were constructed from triply labeled cinnamyl alcohols, using a radical cyclization method.
Asunto(s)
Furanos/síntesis química , Lignanos/síntesis química , Propanoles/química , Isótopos de Carbono , Cromatografía Liquida , Ciclización , Estructura Molecular , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Phytoestrogens are plant-derived compounds with physiologic estrogenic effects. They are present in the plant as glycosidic conjugates, some of which contain further chemical modifications (acetate, malonate, and 3-hydroxy-3-methylglutarate esters and 2,3-dihydroxysuccinate ether). In the gastrointestinal tract, the conjugates undergo hydrolysis catalyzed by enzymes in the intestinal wall and by gut bacteria. On entering the systemic circulation, the phytoestrogens may undergo extensive metabolism to other compounds through reactions involving demethylation, methylation, hydroxylation, chlorination, iodination, and nitration. In addition, all these compounds can undergo conjugation to form beta-glucuronides and sulfate esters. This chapter describes the methods of analysis of all these compounds, the sources of or methods to manufacture suitable standards, and the procedures for examining the enzymes that catalyze these reactions.
Asunto(s)
Fitoestrógenos/análisis , Fitoestrógenos/metabolismo , Catálisis , Fraccionamiento Químico/métodos , Cromatografía Líquida de Alta Presión , Suplementos Dietéticos/análisis , Análisis de los Alimentos , Hidrólisis , Isoflavonas/química , Lignanos/química , Fitoestrógenos/normas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Solventes , Glycine max/químicaRESUMEN
SCOPE: In vitro and in vivo studies suggest that dietary anthocyanins modulate cardiovascular disease risk; however, given anthocyanins extensive metabolism, it is likely that their degradation products and conjugated metabolites are responsible for this reported bioactivity. METHODS AND RESULTS: Human vascular endothelial cells were stimulated with either oxidized LDL (oxLDL) or cluster of differentiation 40 ligand (CD40L) and cotreated with cyanidin-3-glucoside and 11 of its recently identified metabolites, at 0.1, 1, and 10 µM concentrations. Protein and gene expression of IL-6 and VCAM-1 was quantified by ELISA and RT-qPCR. In oxLDL-stimulated cells the parent anthocyanin had no effect on IL-6 production, whereas numerous anthocyanin metabolites significantly reduced IL-6 protein levels; phase II conjugates of protocatechuic acid produced the greatest effects (>75% reduction, p ≤ 0.05). In CD40L-stimulated cells the anthocyanin and its phase II metabolites reduced IL-6 protein production, where protocatechuic acid-4-sulfate induced the greatest reduction (>96% reduction, p ≤ 0.03). Similarly, the anthocyanin and its metabolites reduced VCAM-1 protein production, with ferulic acid producing the greatest effect (>65% reduction, p ≤ 0.04). CONCLUSION: These novel data provide evidence to suggest that anthocyanin metabolites are bioactive at physiologically relevant concentrations and have the potential to modulate cardiovascular disease progression by altering the expression of inflammatory mediators.
Asunto(s)
Antocianinas/farmacología , Ligando de CD40/metabolismo , Células Endoteliales/metabolismo , Glucósidos/farmacología , Interleucina-6/metabolismo , Lipoproteínas LDL/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo , Ácidos Cumáricos/metabolismo , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Expresión Génica , Glucurónidos/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Hidroxibenzoatos/metabolismo , Interleucina-6/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Molécula 1 de Adhesión Celular Vascular/genéticaRESUMEN
Soy isoflavones and other polyphenolics have a number of potentially important beneficial effects on the pro-oxidant aspects of chronic inflammation. The impact of inflammatory cell-specific metabolism of polyphenolics, which can include halogenation and nitration, on the properties of these compounds has not been examined. Using either human neutrophils or differentiated human leukemia cells (HL-60) stimulated with phorbol ester to elicit a respiratory burst, the hypothesis that local generation of reactive oxygen and nitrogen species may metabolize and modify the biological properties of the soy isoflavones was examined. Coincubation of the stimulated cells with genistein or daidzein had no effect on the respiratory burst. Medium from stimulated cells in the presence of the isoflavones and NO(2)(-) increased the inhibition of copper-induced LDL oxidation. Mass spectrometry analysis of this medium revealed that monochlorinated, dichlorinated, and nitrated isoflavones, formed through a myeloperoxidase-dependent mechanism, were present. The consumption of genistein in the presence of cells was both extensive and rapid with > 95% of the genistein converted to either the chlorinated or nitrated metabolites within 30 min. Chemically synthesized 3'-chlorogenistein and 3'-chlorodaidzein increased the inhibition of LDL oxidation by approximately 4-fold and 2-fold over genistein and daidzein, respectively. These results lead to the hypothesis that inflammatory cell-specific metabolism of polyphenolics can modify the properties of these compounds at the local site of inflammation.
Asunto(s)
Antioxidantes/farmacología , Cloro/metabolismo , Isoflavonas/metabolismo , Neutrófilos/enzimología , Nitratos/metabolismo , Peroxidasa/metabolismo , Antioxidantes/química , Diferenciación Celular , Células Cultivadas , Cloro/química , Cromatografía Líquida de Alta Presión , Cobre/química , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Radicales Libres , Genisteína/química , Genisteína/farmacología , Células HL-60 , Humanos , Inflamación , Isoflavonas/química , Isoflavonas/farmacología , Lipoproteínas LDL/química , Espectrometría de Masas , Metamioglobina/química , Modelos Químicos , Nitratos/química , Nitritos/química , Nitrógeno/química , Oxígeno/metabolismo , Especies de Nitrógeno Reactivo , Especies Reactivas de Oxígeno , Estallido Respiratorio , Glycine max , Factores de TiempoRESUMEN
BACKGROUND: Despite significant interest in the risks and benefits of phytoestrogens to human health, few data exist on their pharmacokinetics in humans. OBJECTIVE: We investigated the pharmacokinetics of the (13)C isotopic forms of daidzein and genistein in healthy humans, specifically addressing intraindividual variability, effect of increasing intake, and influence of prolonged exposure to a soy food diet. DESIGN: Premenopausal women (n = 16) were administered 0.4 mg [(13)C]daidzein or [(13)C]genistein/kg body wt orally on 3 occasions, including once after eating soy foods for 7 d. On a further occasion the dose was doubled. Plasma and urinary [(13)C]isoflavone concentrations were measured by mass spectrometry. RESULTS: Serum concentrations of [(13)C]genistein and [(13)C]daidzein peaked after 5.5 and 7.4 h, respectively. The systemic bioavailability and maximum serum concentration of [(13)C]genistein were significantly greater than those of [(13)C]daidzein. The bioavailability of both isoflavones did not increase linearly when the dietary intake was doubled. The mean volume of distribution normalized to bioavailability (V(d)/F), clearance rate, and half-life of [(13)C]daidzein were 336.25 L, 30.09 L/h, and 7.75 h, respectively; the corresponding values for [(13)C]genistein were 258.76 L, 21.85 L/h, and 7.77 h. The average recovery of [(13)C]daidzein and [(13)C]genistein in urine was 30.1% and 9.0% of the dose ingested, respectively. CONCLUSIONS: The serum pharmacokinetics of [(13)C]daidzein and [(13)C]genistein were reproducible among healthy women, and genistein was more bioavailable than was daidzein. Pharmacokinetics were unaffected by chronic exposure to soy foods. Urinary isoflavone concentrations correlated poorly with maximal serum concentrations, indicating the limitations of urine measurements as a predictor of systemic bioavailability. The bioavailability of both isoflavones was nonlinear at higher intakes, suggesting that uptake is rate-limiting and saturable.
Asunto(s)
Estrógenos no Esteroides/farmacocinética , Genisteína/farmacocinética , Isoflavonas/farmacocinética , Proteínas de Soja/administración & dosificación , Adulto , Disponibilidad Biológica , Isótopos de Carbono , Cromanos/metabolismo , Cromanos/orina , Estudios de Cohortes , Relación Dosis-Respuesta a Droga , Equol , Estrógenos no Esteroides/sangre , Estrógenos no Esteroides/orina , Femenino , Cromatografía de Gases y Espectrometría de Masas , Genisteína/sangre , Genisteína/orina , Semivida , Humanos , Isoflavonas/sangre , Isoflavonas/orina , Espectrometría de Masas , Tasa de Depuración Metabólica , Persona de Mediana Edad , Premenopausia , Reproducibilidad de los Resultados , Proteínas de Soja/metabolismoRESUMEN
Subjects of this study consisted of 333 women (aged 45-75 years) drawn from a large United Kingdom prospective study of diet and cancer, the European Prospective Investigation of Cancer and Nutrition-Norfolk study. Using newly developed gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry methods incorporating triply (13)C-labeled standards, seven phytoestrogens (daidzein, genistein, glycitein, O-desmethylangolensin, equol, enterodiol, and enterolactone) were measured in 114 spot urines and 97 available serum samples from women who later developed breast cancer. Results were compared with those from 219 urines and 187 serum samples from healthy controls matched by age and date of recruitment. Dietary levels were low, but even so, mean serum levels of phytoestrogens were up to 600 times greater than postmenopausal estradiol levels. Phytoestrogen concentrations in spot urine (adjusted for urinary creatinine) correlated strongly with that in serum, with Pearson correlation coefficients > 0.8. There were significant relationships (P < 0.02) between both urinary and serum concentrations of isoflavones across increasing tertiles of dietary intakes. Urinary enterodiol and enterolactone and serum enterolactone were significantly correlated with dietary fiber intake (r = 0.13-0.29). Exposure to all isoflavones was associated with increased breast cancer risk, significantly so for equol and daidzein. For a doubling of levels, odds ratios increased by 20-45% [log(2) odds ratio = 1.34 (1.06-1.70; P = 0.013) for urine equol, 1.46 (1.05-2.02; P = 0.024) for serum equol, and 1.22 (1.01-1.48; P = 0.044) for serum daidzein]. These estimates of risk are similar to those established for estrogens and androgens in postmenopausal breast cancer but need confirmation in larger studies.
Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/epidemiología , Suplementos Dietéticos , Isoflavonas/metabolismo , Preparaciones de Plantas/metabolismo , Adulto , Anciano , Análisis de Varianza , Estudios de Casos y Controles , Dieta , Humanos , Incidencia , Isoflavonas/sangre , Isoflavonas/orina , Persona de Mediana Edad , Oportunidad Relativa , Fitoestrógenos , Preparaciones de Plantas/sangre , Preparaciones de Plantas/orina , Probabilidad , Pronóstico , Estudios Prospectivos , Valores de Referencia , Sistema de Registros , Medición de Riesgo , Sensibilidad y Especificidad , Reino Unido/epidemiologíaRESUMEN
BACKGROUND: Kynureninase is a key enzyme on the kynurenine pathway of tryptophan metabolism. One of the end products of the pathway is the neurotoxin quinolinic acid which appears to be responsible for neuronal cell death in a number of important neurological diseases. This makes kynureninase a possible therapeutic target for diseases such as Huntington's, Alzheimer's and AIDS related dementia, and the development of potent inhibitors an important research aim. RESULTS: Two new kynurenine analogues, 3-hydroxydesaminokynurenine and 3-methoxydesaminokynurenine, were synthesised as inhibitors of kynureninase and tested on the tryptophan-induced bacterial enzyme from Pseudomonas fluorescens, the recombinant human enzyme and the rat hepatic enzyme. They were found to be mixed inhibitors of all three enzymes displaying both competitive and non competitive inhibition. The 3-hydroxy derivative gave low Ki values of 5, 40 and 100 nM respectively. An improved 3-step purification scheme for recombinant human kynureninase was also developed. CONCLUSION: For kynureninase from all three species the 2-amino group was found to be crucial for activity whilst the 3-hydroxyl group played a fundamental role in binding at the active site presumably via hydrogen bonding. The potency of the various inhibitors was found to be species specific. The 3-hydroxylated inhibitor had a greater affinity for the human enzyme, consistent with its specificity for 3-hydroxykynurenine as substrate, whilst the methoxylated version yielded no significant difference between bacterial and human kynureninase. The modified purification described is relatively quick, simple and cost effective.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Hidrolasas/metabolismo , Quinurenina/farmacología , Animales , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Hidrolasas/genética , Quinurenina/análogos & derivados , Quinurenina/síntesis química , Quinurenina/química , Ratas , Proteínas Recombinantes/aislamiento & purificaciónRESUMEN
As the purines, in particular adenosine, are important signaling agents in the nervous system we have devised a new biosensor for directly measuring their production in real time during physiological activity. Our amperometric adenosine biosensor is made by entrapping 3 enzymes (xanthine oxidase, purine nucleoside phosphorylase and adenosine deaminase) in a composite lactobionamide and amphiphillic polypyrrole matrix around a Pt microelectrode. The resulting sensors are small (25-100 microm diameter), fast responding (10-90% rise time, 2+/-0.23 s), sensitive (100-222 mA M(-1) cm(-2)) and stable (100% activity after 5 days). The sensor was used in vivo to demonstrate the spatial localization of release of adenosine from Xenopus embryo spinal cord during fictive swimming.
Asunto(s)
Técnicas Biosensibles/instrumentación , Purinas/análisis , Animales , Sistema Nervioso Central/metabolismo , Electrodos , Purinas/metabolismo , XenopusRESUMEN
The major and structurally unique glucosinolate (GLS) in leaves of Eruca sativa L. (salad rocket) was identified as 4-mercaptobutyl GLS. Both 4-methylthiobutyl GLS and 4-methylsulfinylbutyl GLS were also present, but at lower concentrations. The 4-mercaptobutyl GLS was observed to oxidise under common GLS extraction conditions, generating a disulfide GLS that may be reduced efficiently by tris(2-carboxyethyl) phosphine hydrochloride (TCEP) to reform the parent molecule. The identities of 4-mercaptobutyl GLS and of the corresponding dimeric GLS were confirmed by LC/MS, MS/MS and NMR. Myrosinase treatment of an enriched GLS fraction or of the purified dimer GLS generated a mixture of unique bi-functional disulfides, including bis-(4-isothiocyanatobutyl) disulfide (previously identified elsewhere). TCEP reduction of the purified dimer, followed by myrosinase treatment, yielded only 4-mercaptobutyl ITC. GLS-derived volatiles generated by autolysis of fresh seedlings and true leaves were 4-mercaptobutyl ITC (from the newly identified GLS), 4-methylthiobutyl ITC (from 4-methylthiobutyl GLS) and 4-methylsulfinylbutyl ITC (from 4-methylsulfinyl-butyl GLS); no unusual bi-functional disulfides were found in fresh leaf autolysate. These results led to the conclusion that, in planta, the new GLS must be present as 4-mercaptobutyl GLS and not as the disulfide found after extraction and sample concentration. This new GLS and its isothiocyanate are likely to contribute to the unique odour and flavour of E. sativa.
Asunto(s)
Brassicaceae/química , Glucosinolatos/análisis , Hojas de la Planta/química , Cromatografía Liquida , Glucosinolatos/química , Glucosinolatos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Glucosinolates are naturally occurring plant compounds that may be important in the dietary prevention of cancer. This study shows that they can be detected in their intact form by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with a high degree of sensitivity. The methodology was used to characterize a number of individual glucosinolates either produced by synthetic chemistry or isolated from plants. The method was used for crude plant extracts to rapidly examine the glucosinolate profile of the plant. The results for a range of plant extracts showed good agreement with previous LC-MS analysis of the desulfoglucosinolates from the same samples.
Asunto(s)
Glucuronatos/química , Plantas/química , Glucuronatos/aislamiento & purificación , Modelos Moleculares , Extractos Vegetales/química , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
This communication describes the synthesis of a new class of N-hydroxyguanidine (NHG) pro-drugs which release nitric oxide (NO), triggered by the action of γ-glutamyl transpeptidase (γ-GT), and have potential for the treatment of acute renal injury/failure (ARI/ARF).
Asunto(s)
Óxido Nítrico/metabolismo , Profármacos/metabolismo , Vasodilatadores/metabolismo , gamma-Glutamiltransferasa/metabolismo , Lesión Renal Aguda/tratamiento farmacológico , Guanidinas/química , Humanos , Hidroxilaminas , Profármacos/química , Profármacos/uso terapéutico , Vasodilatadores/química , Vasodilatadores/uso terapéuticoRESUMEN
BACKGROUND: Evidence suggests that the consumption of anthocyanin-rich foods beneficially affects cardiovascular health; however, the absorption, distribution, metabolism, and elimination (ADME) of anthocyanin-rich foods are relatively unknown. OBJECTIVE: We investigated the ADME of a (13)C5-labeled anthocyanin in humans. DESIGN: Eight male participants consumed 500 mg isotopically labeled cyanidin-3-glucoside (6,8,10,3',5'-(13)C5-C3G). Biological samples were collected over 48 h, and (13)C and (13)C-labeled metabolite concentrations were measured by using isotope-ratio mass spectrometry and liquid chromatography-tandem mass spectrometry. RESULTS: The mean ± SE percentage of (13)C recovered in urine, breath, and feces was 43.9 ± 25.9% (range: 15.1-99.3% across participants). The relative bioavailability was 12.38 ± 1.38% (5.37 ± 0.67% excreted in urine and 6.91 ± 1.59% in breath). Maximum rates of (13)C elimination were achieved 30 min after ingestion (32.53 ± 14.24 µg(13)C/h), whereas (13)C-labeled metabolites peaked (maximum serum concentration: 5.97 ± 2.14 µmol/L) at 10.25 ± 4.14 h. The half-life for (13)C-labeled metabolites ranged between 12.44 ± 4.22 and 51.62 ± 22.55 h. (13)C elimination was greatest between 0 and 1 h for urine (90.30 ± 15.28 µg/h), at 6 h for breath (132.87 ± 32.23 µg/h), and between 6 and 24 h for feces (557.28 ± 247.88 µg/h), whereas the highest concentrations of (13)C-labeled metabolites were identified in urine (10.77 ± 4.52 µmol/L) and fecal samples (43.16 ± 18.00 µmol/L) collected between 6 and 24 h. Metabolites were identified as degradation products, phenolic, hippuric, phenylacetic, and phenylpropenoic acids. CONCLUSION: Anthocyanins are more bioavailable than previously perceived, and their metabolites are present in the circulation for ≤48 h after ingestion. This trial was registered at clinicaltrials.gov as NCT01106729.
Asunto(s)
Antocianinas/administración & dosificación , Antocianinas/farmacocinética , Glucósidos/administración & dosificación , Glucósidos/farmacocinética , Absorción , Administración Oral , Adulto , Antocianinas/sangre , Antocianinas/orina , Disponibilidad Biológica , Índice de Masa Corporal , Cromatografía Líquida de Alta Presión/métodos , Ingestión de Energía , Heces/química , Estudios de Seguimiento , Glucósidos/sangre , Glucósidos/orina , Semivida , Humanos , Marcaje Isotópico/métodos , Masculino , Espectrometría de Masas/métodos , Adulto JovenRESUMEN
Acute renal failure (ARF) has high mortality and no effective treatment. Nitric oxide (NO) delivery represents a credible means of preventing the damaging effects of vasoconstriction, central to ARF, but design of drugs with the necessary renoselectivity is challenging. Here, we developed N-hydroxyguanidine NO donor drugs that were protected against spontaneous NO release by linkage to glutamyl adducts that could be cleaved by γ-glutamyl transpeptidase (γ-GT), found predominantly in renal tissue. Parent NO donor drug activity was optimized in advance of glutamyl adduct prodrug design. A lead compound that was a suitable substrate for γ-GT-mediated deprotection was identified. Metabolism of this prodrug to the active parent compound was confirmed in rat kidney homogenates, and the prodrug was shown to be an active vasodilator in rat isolated perfused kidneys (EC50 ~50 µM). The data confirm that glutamate protection of N-hydroxyguanidines is an approach that might hold promise in ARF.
Asunto(s)
Lesión Renal Aguda/tratamiento farmacológico , Guanidinas/farmacología , Riñón/efectos de los fármacos , Donantes de Óxido Nítrico/farmacología , Lesión Renal Aguda/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Cristalografía por Rayos X , Ácido Glutámico/química , Guanidinas/síntesis química , Guanidinas/metabolismo , Hidroxilaminas , Técnicas In Vitro , Riñón/metabolismo , Masculino , Modelos Químicos , Estructura Molecular , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/síntesis química , Donantes de Óxido Nítrico/metabolismo , Profármacos/síntesis química , Profármacos/metabolismo , Profármacos/farmacología , Ratas , Ratas Wistar , Vasodilatadores/síntesis química , Vasodilatadores/metabolismo , Vasodilatadores/farmacologíaRESUMEN
The major dietary anthocyanin, cyanidin-3-glucoside, was prepared on a 4 g scale from three units of diethyl [2-(13)C]malonate and one unit of [1,3-(13)C(2)]acetone, such that five isotope locations were distributed throughout the molecule to provide a penta-(13)C(5)-labelled anthocyanin, [6,8,10,3',5'-(13)C(5)]cyanidin-3-glucoside chloride, for use in human stable-isotope tracer studies.