RESUMEN
A quantitative (1)H-NMR method (qHNMR) was used to measure paeoniflorin content in Paeoniae radix (dried root of Paeonia lactiflora), of which paeoniflorin is a major component. The purity of paeoniflorin was calculated from the ratio of the intensity of the H-9 signal at δ 5.78 ppm of paeoniflorin to that of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability by using bisphenol A of certified reference material (CRM) grade. The paeoniflorin content in 2 separate samples of Paeoniae radix was determined by qHNMR and was found to be 2.15 and 2.45%. We demonstrated that this method is useful for quantitative analysis of crude drugs.
Asunto(s)
Benzoatos/análisis , Hidrocarburos Aromáticos con Puentes/análisis , Glucósidos/análisis , Espectroscopía de Resonancia Magnética , Paeonia/química , Calibración , Espectroscopía de Resonancia Magnética/normas , Monoterpenos , Raíces de Plantas/química , Plantas MedicinalesRESUMEN
The protective effects of cyclic dipeptides in alcoholic beverages were investigated in the perfused guinea-pig hearts subjected to ischemia and reperfusion. Subsequently, in order to determine the importance of cyclic dipeptide structure, the effects of cyclo(L-Leu-L-Tyr) (cLY) were compared with those of the newly synthesized non-cyclic dipeptides, L-Leu-L-Tyr (LY) and L-Tyr-L-Leu (YL). After reperfusion, pressure recovery (%) in the left ventricle reached a peak of over 90% in the presence of cLY (10(-6) M and 10(-5) M) (control: 22.9%). The recovery by LY and YL was significantly lower than that by cLY, and ATP levels simultaneously monitored using (31)P-NMR were already lower during the ischemic end period than those observed with cLY treatment. In perfused mitochondrial preparations, cLY significantly inhibited mitochondrial Ca(2+) ([Ca(2+)](m)) elevation in a similar way to that of the mitochondrial permeability transition pore (MPTP) inhibitor cyclosporin A. In vitro electron paramagnetic resonance (EPR) revealed that the active oxygen radicals quenching activity of cLY was greater than those of non-cyclic dipeptides. cLY inhibited caspase-3-induced apoptosis. The cyclic dipeptide structure inhibits opening of the MPTP by preventing [Ca(2+)](m) overload-induced apoptosis related to mitochondrial active oxygen radical accumulation in ischemia-reperfusion hearts.
Asunto(s)
Antioxidantes/uso terapéutico , Proteínas de Transporte de Membrana Mitocondrial/antagonistas & inhibidores , Isquemia Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/metabolismo , Péptidos Cíclicos/uso terapéutico , Disfunción Ventricular Izquierda/tratamiento farmacológico , Adenosina Trifosfato/metabolismo , Animales , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Fármacos Cardiovasculares/farmacología , Fármacos Cardiovasculares/uso terapéutico , Caspasa 3/metabolismo , Ciclosporina/farmacología , Dipéptidos/farmacología , Dipéptidos/uso terapéutico , Femenino , Cobayas , Masculino , Mitocondrias/metabolismo , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Miocardio/patología , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Relación Estructura-Actividad , Disfunción Ventricular Izquierda/metabolismoRESUMEN
Berberine, palmatine, and coptisine are major pharmacologically active protoberberine alkaloids in Coptidis Rhizoma, and have been used as indices for chemical evaluation of the crude drug. (1)H-NMR spectroscopy was applied to determination of purities of commercial reagents of protoberberine alkaloids. The purities of the alkaloids were calculated from the ratios of the intensities of the H-13 singlet signal at about δ 8.7 ppm of target protoberberine alkaloids to integration of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability using potassium hydrogen phthalate of certified reference material (CRM) grade. The purity of the reagent estimated by the (1)H-NMR was, in general, lower than that claimed by the manufacturer, leading to over-estimation of the alkaloid contents of Coptidis Rhizoma when determined by HPLC. The present quantitative (1)H-NMR method was also applicable to direct determination of protoberberine alkaloid contents in Coptidis Rhizoma.
Asunto(s)
Alcaloides de Berberina/química , Coptis/química , Espectroscopía de Resonancia Magnética/métodos , Berberina/análogos & derivados , Berberina/química , Cromatografía Líquida de Alta Presión , Estructura Molecular , Extractos Vegetales/químicaRESUMEN
(1)H-NMR spectroscopy was successfully applied to the quantitative determination of atractylon in Atractylodis Rhizoma (dried rhizomes of Atractylodes ovata and A. japonica) and Atractylodis Lanceae Rhizoma (dried rhizomes of Atractylodes lancea and A. chinensis). The analysis was carried out by comparing the integral of the H-12 singlet signal of atractylon, which was well separated in the range of delta 6.95-7.05 ppm in the NMR spectrum, with the integral of a hexamethyldisilane (HMD) signal at delta 0 ppm. The atractylon contents obtained by the (1)H-NMR spectroscopy were consistent with those obtained by the conventional HPLC analysis. The present method requires neither reference compounds for calibration curves nor sample pre-purification. It also allows simultaneous determination of multiple constituents in a crude extract. Thus, it is applicable to chemical evaluation of crude drugs as a powerful alternative to various chromatographic methods.
Asunto(s)
Atractylodes , Resonancia Magnética Nuclear Biomolecular , Extractos Vegetales/análisis , Rizoma , Sesquiterpenos/análisis , Evaluación Preclínica de Medicamentos/métodos , Medicamentos Herbarios Chinos/análisis , Resonancia Magnética Nuclear Biomolecular/métodos , ProtonesRESUMEN
A new structure for an adenine-selective host molecule, featuring the pertinent link of five-six-five-membered heteroaromatic rings and two carbamoyl NH sites, was developed. This structure provides a correctly oriented array of complementary hydrogen bonding sites for the adenine nucleobase, which exploits both Watson-Crick and Hoogsteen-type interactions. The complexation with adenine nucleobases by multiple hydrogen bonding was supported by (1)H NMR spectroscopy. This type of host displayed high selectivity in complexation, with an accompanying fluorescent response to lipophilized adenosine in CHCl(3). Furthermore, a remarkably selective potentiometric response was attained for adenosine 5'-monophosphate over 5'-GMP, 5'-CMP, and 5'-UMP by using an ion-selective electrode with a PVC-supported solvent polymeric membrane. This indicates recognition of water-soluble nucleotide guests through the membrane-water interface. These findings are expected to form a reliable basis for the development of artificial sensing systems for mononucleotides in biological systems.