ABSTRACT
Objective:To establish the HPLC fingerprint of Centellae herba and determine the content of asiaticoside, madecassic acid and asiaticoside B simultaneously; To compare the quality differences of Centellae herba collected in different months. Methods:The chromatographic condition was a Shimadzu InertSustain C18 column (4.6 mm×250 mm, 5 μm) with a mobile phase consisting of acetonitrile and 2 mmol/L beta cyclodextrin in gradient elution at the flow rate of 0.8 ml/min. The detection wavelength was 204 nm, and the column temperature was 30 ℃. The different Centellae herba materials of collected in 2-12 months from Chenzhou were studied by the similarity evaluation combined with cluster analysis, principal component analysis and the three contents determination. Results:The HPLC fingerprint of Centellae herba was established and 9 common peaks were designated. The eleven samples were different, which can be aggregated into 4 categories and the quality of Centellae herba collected in July was the best. Conclusion:The established fingerprint and multi-components quantitative method are stable and reliable, which can provide a reference for the quality control and the utilization of Centellae herba resource.
ABSTRACT
Selectively activating the distal inactive C-H bond for functionalization is one of the on-going challenge in organic synthetic chemistry. In recent years, benefiting from the development of selective synthesis methods, novel methodologies not only make it possible to break non-traditional chemical bonds and attain more diversity in inactive sites, but also provide more possibilities for the diversification of complex natural products. Direct C-H bond functionalization approaches make it feasible to explore structure-activity relationship (SAR), generate metabolites and derivatives, and prepare biological probes. Among them, direct oxidation of inert C-H bonds is one of the most common methods for natural product diversification. In this review, we focus on the application of remote functionalization of inert C-H bonds for natural products derivatization, including the establishment of oxidation methods, the regulation of reaction sites, and the biological activities of derivatives. We highlight the challenges and opportunities of remote functionalization of inert C-H bonds for natural product diversification through selected and representative examples. We try to show that inert C-H bond oxidation, properly regulated and optimized, can be a powerful and efficient strategy in both synthetic and medicinal chemistry.
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The traditional primary culture methods of human normal epithelial cells have disadvantages of low activity of cultured cells,the low cultivated rate and complicated operation.To solve these problems,researchers made many studies on culture process of human normal primary epithelial cell.In this paper,we mainly introduce some methods used in separation and purification of human normal epithelial cells,such as tissue separation method,enzyme digestion separation method,mechanical brushing method,red blood cell lysis method,percoll layered medium density gradient separation method.We also review some methods used in the culture and subculture,including serum-free medium combined with low mass fraction serum culture method,mouse tail collagen coating method,and glass culture bottle combined with plastic culture dish culture method.The biological characteristics of human normal epithelial cells,the methods of immunocytochemical staining,trypan blue exclusion are described.Moreover,the factors affecting the aseptic operation,the conditions of the extracellular environment,the conditions of the extracellular environment during culture,the number of differential adhesion,and the selection and dosage of additives are summarized.
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Objective To study the effects of ischemic postconditioning and ischemic preconditioning on cerebral ischemia-reperfusion injury following middle cerebral artery occlusion in rats.Methods A reversible focal cerebral ischemia-reperfusion injury was modeled using middle cerebral artery occlusion. Thirty male Sprague-Dawley rats were randomized into three groups (n = 10 in each group) : a cerebral ischemia-reperfusion group, an ischemic postconditioning group and an ischemic preconditioning group. The impairment of neurological function was scored and the infarct volume, the activity of superoxide dismutase and malondiadehyde (MDA) content were measured after the operation.Results In the ischemic postconditioning and preconditioning groups the neurological function was better and the infarction volume was significantly smaller compared with the model group. In the preconditioning group both infarction volume and neurological function were significantly better than in the postconditioning group. In the brain tissues of the preconditioning and postconditioning groups MDA content was lower, while the activity of superoxide dismutase was significantly higher than in the model group.Conclusions lschemic postconditioning can attenuate pathological injury induced by focal cerebral ischemia and repedusion. The neuroprotective effect induced by ischemic preconditioning is stronger than that induced by ischemic postconditioning.
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AIM:To observe the therapeutic effect of dihydromyricetin on experimental schistosoma japonicum hepatic fibrosis in mice. METHODS:60 mice infected with schistosma japonicum cercariae percutanoeusly were divided into 3 groups:model group,praziquantel group, praziquantel plus dihydromyricetin group and other 20 normal mice were used as control group.After treatment with medicine for 8 weeks,the liver was removed and weighed.The contents of ALT and AST in serum were assayed using the corresponding kits.Moreover, the degree of hepatic fibrosis was observed Via HE and was scored.The expression of collagenⅠprotein and collagenⅢprotein were measured by immunohistochernical method.RESULTS: The mice that infected with schistosoma japonicum, had a featuring increment in liver weights,serum ALT,AST contents,the expression of collagenⅠprotein,collagenⅢprotein (P
