ABSTRACT
Four pyrazines were isolated from the n-butanol fraction of Hypecoum erectum L. by using various chromatographic methods, including MCI gel, ODS, silica gel and semi-preparative HPLC. The structures of the isolated compounds were identified as hyperectpyrazin A (1), 1′S-(6-methylpyrazin-2-yl)-ethane-1′,2′-diol (2), 2-hydroxymethyl-6-methylpyrazin (3) and pyrazine-2-carboxylic acid (4) by spectroscopy methods (1D NMR, 2D NMR, UV, IR, MS, etc.). The absolute configuration of compound 2 was determined by using the Mo2(OAc)4 induced CD analysis for the first time. Compound 1 was a new compound, compounds 2-4 were isolated from H. erectum for the first time. Compounds 1-4 were evaluated for their inhibition against acetylcholinesterase and nitric oxide generation induced by lipopolysaccharide-RAW264.7 macrophage cells. At a concentration of 50 μmol·L-1, compounds 2 and 4 displayed inhibitory effects on acetylcholinesterase with the inhibition rates of 44.40% and 43.99%, respectively.
ABSTRACT
Objective:To establish the high performance liquid chromatography （HPLC） fingerprint of Citri Sarcodactylis Fructus， and to search for makers to characterize the quality difference of Citri Sarcodactylis Fructus from different origins coupled with chemometrics. Method:The analysis was performed on a Thermo Hypersil GOLD C<sub>18</sub> column （4.6 mm×250 mm， 5 μm） with mobile phase consisted of acetonitrile-0.05% phosphoric acid solution for gradient elution， and the detection wavelength was set at 254 nm. A total of 31 batches of samples were analyzed to establish the HPLC fingerprint of Citri Sarcodactylis Fructus. Similarity evaluation was performed by Traditional Chinese Medicine Chromatographic Fingerprint Similarity Evaluation System （2012 edition） to confirm the common peaks， which were identified by comparison of reference substances. On the basis， chemometrics methods were used to analyze and evaluate the quality of Citri Sarcodactylis Fructus from different origins. At the same time， 3 batches of 5 species of decoction pieces from the genus <italic>Citrus</italic> in the family Rutaceae， including Citri Sarcodactylis Fructus， Aurantii Fructus Immaturus， Aurantii Fructus， Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium， were randomly collected for evaluating the effectiveness and reliability of the established HPLC fingerprint of Citri Sarcodactylis Fructus. Result:HPLC fingerprint of Citri Sarcodactylis Fructus was established and 22 common peaks were identified. And seven common peaks among them were identified as 6，7-dimethoxycoumarin， diosmin， hesperidin， byakangelicin， 5，7-dimethoxycoumarin， bergapten and oxypeucedanin. Except for 2 batches of samples， the similarities of fingerprints between other 29 batches of samples were >0.9. The 31 batches of Citri Sarcodactylis Fructus were basically divided into 3 groups by cluster analysis and principal component analysis， which were consistent with the classification of three different producing areas. Eight differential markers were screened by orthogonal partial least squares discriminant analysis and four of them （5，7-dimethoxycoumarin， bergapten， 6，7-dimethoxycoumarin and diosmin） were identified by reference substances. Similarity evaluation of 5 species of decoction pieces from genus <italic>Citrus</italic> in the family Rutaceae was carried out by taking the reference fingerprint of Citri Sarcodactylis Fructus as treference chromatogram， similarity of Citri Sarcodactylis Fructus decoction pieces was 0.892-0.977， and the similarities of the other 4 kinds of decoction pieces were 0.215-0.517. Conclusion:The established fingerprint method is reasonable， effective and accurate for quality control of Citri Sarcodactylis Fructus， the characterization information is more comprehensive combined with chemometrics.
ABSTRACT
<p><b>OBJECTIVE</b>To study the diagnostic value of the signal intensity on T1-weighted images of MRI and proton magnetic resonance spectroscopy (1H MRS) for neonatal hypoxic-ischemic encephalopathy (HIE).</p><p><b>METHODS</b>Thirty full-term neonates with HIE admitted into the Department of Neonatology of the First Affiliated Hospital of Medical College, Xi'an Jiaotong University between January, 2007 and December 2009 were enrolled. Ten normal neonates born at the same period served as control group. Cerebral MRI and 1H MRS examinations were performed within 15 days after birth.</p><p><b>RESULTS</b>In the HIE group, the signal intensity of the posterolateral lentiform nucleus was higher than or equal to that of the posterior limb of internal capsule, but in the control group, the results were opposite, namely, the signal intensity of the postero-lateral lentiform nucleus was lower than that of the posterior limb of internal capsule. The ratios of lactic acid/creatinine and glutamate/creatinine in the basal ganglia and the frontal lobe shown by 1H MRS increased significantly in the HIE group compared with controls (P<0.05 or 0.01). The differences of the signal intensity between the posterolateral lentiform nucleus and the posterior limb of internal capsule were positively correlated with the ratios of lactic acid/creatinine and glutamate/creatinine shown by 1H MRS (P<0.05).</p><p><b>CONCLUSIONS</b>The comparison of the signal intensity between the posterolateral lentiform nucleus and the posterior limb of internal capsule on T1-weighted images of the cerebral MRI is valuable for the diagnosis of neonatal HIE and the accuracy of diagnosis can be improved when combined with 1H MRS.</p>