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OBJECTIVE: To study the chemical constituents from Melilotus officinalis(L.) and their anti-oxidant activities. METHODS: DPPH Assay and β-carotene bleaching assay were used for screening the fraction of anti-oxidant activity in the 70% ethanol extract of Melilotus officinalis(L.). The isolation and purification were performed by silica,Sephadex LH-20 and preparative columns. The structures of the obtained compounds were identified by physicochemical properties and spectral data. Then their anti-oxidant activities were evaluated. RESULTS: The ethyl acetate fraction from Melilotus officinalis(L.) showed the most significant anti-oxidant activity. Thirteen compounds were isolated and identified as kaempferol(1), luteolin(2), quercetin(3), hesperidin(4), rutin(5), apigenin(6), salicylic acid(7), coumarin(8), scoparone(9), 7-methoxycoumarin(10), fumaric acid(11), caffeic acid(12), and p-hydroxybenzoate-4-O-α-D-mannopyranosyl-(1→3)-α-L-rhamnoside(13).Compounds 2, 4, 7 and 12 exhibited strong scavenging activities against DPPH free radical with the IC50 values of 25.89, 14.09, 28.03, and 23.04 μg•mL-1, respectively; compounds 4, 7, 12 and 13 exhibited strong scavenging activities against ABTS free radical with the IC50 values of 10.48, 23.77, 22.79, and 25.20 μg•mL-1, respectively. CONCLUSION: Compounds 3, 7, 9, 10, 11, 12, and 13 are isolated from this plant for the first time. Compound 13 is a new compound not reported in the literature; compounds 2, 4, 7, and 12 have strong ability to scavenge DPPH free radicals; compounds 4, 7, 12, and 13 have strong ability to scavenge ABTS free radicals.
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Objective: To understand the in vivo metabolic fate of 1,2,3,4,6-Penta-O-galloyl-β-D-glucose (PGG) naturally existed in many medicinal herbs and food plants such as Rhus chinensis, Paeonia suffruticosa, Paeonia lactiflora and Mango. Methods: The metabolites of PGG in rat biofluids were characterized using high performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS). Results: Ten metabolites in urine, five metabolites in feces and two metabolites in plasma, were observed when the rats were administrated with a single intravenous injection of PGG (20 mg/kg). Conclusion: PGG is firstly metabolized to gallic acid, then gallic acid undergoes sulfation, glucuronidation and methylation by rat liver. The determination of metabolites and the proposed metabolic pathway of PGG in vivo will be benefit to gain deeper insights into its pharmacological activities.
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Background Researches showed that as the non-optical factors,cognitive has certain influence on the regulating system.So accurately experimental design is one of the key steps that evaluates the non-optical factors on regulating system.Objective The present study was to investigate the influence of presenting pattern of target and watching way on the level and amplitude of accommodative fluctuate and to analyze the effect of focus gaze of cognitive on regulating system and the relationship between focus gaze condition under near work and the development of myopia.Methods This study complied with Declaration of Helsinki,and the permission of Ethic Committee and written informed consent was obtained before entering in this trial.Thirty healthy volunteers were included with the mean age (24.80 ± 1.98) years old,equivalent refractive diopter (-1.92 ± 2.02) D and mean cylinder (-0.19±0.58) D.The presenting pattern of the targets was designed as focus gaze and relaxed gaze.The accommodative response and accommodative fluctuation in the complete corrected right eyes for the different targets at the 40 cm under the gazing state was recorded with Grand Seiko WAM 5500 automatic infrared refractor in the experiment.Results The mean accommodative response value was (1.86±0.26) D under the focus gaze and (1.27±0.39) D under the relax gaze,showing a statistically significant difference (t=-8.052,P=0.000).The mean fluctuate value was(0.17±0.06) D under the focus gaze,with a significant lowing in comparison with (0.28±0.17) D under the relax gaze (t =3.600,P =0.001).Conclusions These results demonstrate that the different presenting patterns of sighting target and watching ways of the subjects affect accommodation system.The accommodative response was relatively more accurate with a smaller microwavc moving under the focus gaze condition.