广山楂HPLC指纹图谱建立及其活血化瘀作用谱效关系研究

目的 建立广山楂Malus doumeri指纹图谱,测定各批次广山楂的“活血化瘀”药效学指标,探讨广山楂化学成分与活血化瘀功效的谱效关系。方法 采用HPLC法建立18批广山楂的指纹图谱。利用大鼠高脂模型,测定不同批次广山楂的“活血化瘀”药效学指标,包括高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）、低密度脂蛋白胆固醇（low density lipoprotein cholesterin,LDL-C）、总胆固醇（total cholesterol,TC）、三酰甘油（triglyceride,TG）含量及血液流变学指标等。运用偏最小二乘回归法（partial least-square method regression,PLSR）、灰色关联度分析法,分析广山楂化学成分与活血化瘀药效指标间的谱效关系。结果 构建了广山楂的HPLC图谱,确定了6个共有峰,并指认了其中的2个共有峰（绿原酸、根皮苷）。活血化瘀实验表明,不同批次广山楂活血药效指标间具有明显差异,在标定的广山楂6个特征峰中,峰2～6与HDL-C呈正相关,峰1、5、6与LDL...     

根皮苷可增强索拉非尼抑制肝癌细胞能量代谢及活力

目的：探讨根皮苷联合索拉非尼对肝癌细胞能量代谢与凋亡的影响。方法：将根皮苷5 μmol/L和（或）索拉非尼5 μmol/L作用于HepG2细胞48 h后,检测肝癌细胞活力、肝癌细胞葡萄糖摄取与细胞内ATP含量、caspase-3活力与凋亡细胞计数。结果：索拉非尼组肝癌细胞活力降低,与对照组差异有统计学意义（P<0.05）;索拉非尼与根皮苷联合组肝癌细胞活力进一步降低,与其他各组（对照组、索拉非尼组及根皮苷组）差异均有统计学意义（P<0.05）。根皮苷组葡萄糖摄取及ATP生成减少,与对照组差异有统计学意义（P<0.05）;索拉非尼与根皮苷联合组葡萄糖摄取及ATP生成进一步减少,与其他组差异均有统计学意义（P<0.05）。索拉非尼组与根皮苷组caspase-3活力与细胞凋亡较对照组增强（P<0.05）;索拉非尼与根皮苷联合组caspase-3活力与细胞凋亡进一步增强,与其他组差异均有统计学意义（P<0.05）。结论：根皮苷可以通过抑制肿瘤细胞ATP生成和促进肿瘤细胞凋亡来提高索拉非尼疗效。     

Glucose transport across isolated bovine pigment epithelium

Glucose transport across the isolated bovine pigment epithelium was studied in vitro by mounting the tissue in a chamber and exposing the apical and basal surfaces to separate solutions. Analysis of the total unidirectional glucose fluxes, for both directions, indicates that a carrier-mediated transport system exists with a significant net flux in the choroid to retina direction. The apparent kinetic constants of carrier-mediated glucose transport are: K_m = 9·5 mm, V_max = 0·71 μmol/cm²/hr for the retina to choroid direction, and K_m = 27 mm, V_max = 2·1 μmol/cm²/hr for the choroid to retina direction. Comparison of the kinetic parameters show that only the maximum velocities were significantly different. The total unidirectional glucose fluxes were insensitive to phloridzin (0·1 mm), sodium reduction (50%) and potassium reduction (90%). Phloretin (0·1 mm) and calcium reduction (90%) were effective in reducing the total unidirectional flux significantly in both directions. These findings suggest that glucose transport across bovine pigment epithelium involves a carrier-mediated transport system, and calcium is an effective modulator of the unidirectional glucose flux.     

Studies on the depression of gamma-aminobutyric acid potentials by phloridzin in cat dorsal root ganglion cells in vitro

Phloridzin has been used as a tool to investigate membrane transport mechanisms. We have demonstrated that phloridzin acts to depress chloride flux resulting from activation of a gamma-aminobutyric acidA (GABAA) receptor on cat dorsal root ganglion cells. This action appears not to involve an inwardly directed chloride pump postulated for these neurons but rather affects a site associated with the GABA receptor-chloride complex.     

Novel modified Ussing chamber for the study of absorption and secretion in human endoscopic biopsies

The aim of this study was to design and evaluate a modified Ussing chamber, that makes use of constant air suction (modified Ussing air suction chamber, MUAS) for fixation of biopsy specimens. Standard size forceps biopsies were taken from the descending part of duodenum from patients undergoing endoscopy. Short circuit current (SCC) and conductance (G) were measured during basal conditions and after addition of different sugars and secretagogues. Histologic examination was performed to determine the degree of tissue damage after study in the chamber. Basal SCC was 54.7 ± 4.3 μA cm^–2 and G was 58.7 ± 4.7 mS cm^–2 (mean ± SEM, n=48) and steady values of these parameters were observed for at least 2 h. Reproducible and steady responses in SCC were obtained with D ‐glucose (SCC_max=172 ± 22.1 μA cm^–2; EC₅₀=6.9 ± 0.7 mM , n=5) and D ‐galactose (SCC_max=233 ± 55.7 μA cm^–2; EC₅₀=9.2 ± 0.7 mM , n=3), and secretory responses with 5‐hydroxytryptamine, 100 μM (ΔSCC= 16.1 ± 3.8 μA cm^–2, n=10), histamine, 100 μM (ΔSCC=24.0 ± 4.1 μA cm^–2, n=10) and prostaglandin E₂, 1 μM (ΔSCC=30.3 ± 5.4 μA cm^–2, n=6). Experimental biopsy specimens showed intact surface epithelium by histologic examination and did not differ from controls apart from minor indications of edge damage. No difference in basal electrical parameters and D ‐glucose fluxes were found between Helicobacter pylori positive and negative patients. Our data suggests that the MUAS chamber represents a promising alternative approach to measure transport processes in intestinal endoscopic biopsies.     

反相高效液相色谱法测定根皮苷原料药的含量

目的采用反相高效液相色谱法测定根皮苷原料药含量,以满足质量控制的要求。方法采用RP-HPLC法,色谱柱为Inertsil ODS-3柱(4.6×150 mm,5μm)。流动相为乙腈-0.15%磷酸(25∶75),柱温30℃,流速1.0 ml/min,检测波长285nm。结果此条件下根皮苷分离良好,在0.4950～49.50μg·mL-1浓度范围内线性关系良好,回归方程为:Y=46.370X-0.673(r=0.9999,n=3),平均回收率为99.40%,相对标准偏差为0.67%。结论建立根皮素原料药含量测定的HPLC方法专属性强、灵敏度高,为根皮素质量控制提供参考依据。     

红槭树枝条酚类成分及其抗氧化和抑制α-葡萄糖苷酶活性研究

目的 研究红槭树枝条甲醇提取物中的酚类化学成分及其抗氧化和抑制α-葡萄糖苷酶活性.方法 采用甲醇浸泡提取红槭树枝条,系统溶剂萃取其甲醇提取物,并用硅胶、Sephadex LH-20、ODS和制备HPLC等各种柱色谱技术对其醋酸乙酯部位进行分离纯化,根据化合物的理化性质和谱学数据鉴定化合物结构,并对单体化合物进行DPPH自由基清除和抑制α-葡萄糖苷酶活性测试.结果 从红槭树枝条醋酸乙酯部位中分离得到了10个酚类化合物,分别鉴定为儿茶素(1)、表儿茶素(2)、表儿茶素-3-O-没食子酸酯(3)、槲皮素-3-O-α-L-鼠李糖苷(4)、槲皮素-3-O-(3"-没食子酰基)-吡喃鼠李糖苷(5)、槲皮素-3-O-(2"-没食子酰基)-吡喃鼠李糖苷(6)、根皮苷(7)、条茶槭甲素(8)、条茶槭乙素(9)和条茶槭丙素(10).结论 化合物3、5～7为首次从红槭树枝条中分离得到,其中化合物7是首次从槭树科植物中分离得到的一个查耳酮类成分.所有化合物均具有很强的抗氧化活性,化合物3和8具有很强的抑制α-葡萄糖苷酶活性.     

Synthesis of deuterated dihydrochalcones

The dihydrochalcones phloretin and phloridzin are major phenolic constituents of apple fruit. Phloretin‐d₄, deuterated at both the α and β positions, was prepared by hydrogenolysis of naringenin and by deuterium exchange from unlabelled phloretin using Pd/C and sodium formate with methanol‐d₁ as the source of deuterium. Deuterated derivatives of the glycosides, phloridzin and naringin dihydrochalcone, were similarly prepared. Copyright © 2006 John Wiley & Sons, Ltd.     

木姜叶柯总黄酮分离纯化研究

目的优选木姜叶柯总黄酮的分离纯化工艺。方法以总黄酮中主要有效成分根皮苷为优选指标,采用静态与动态吸附洗脱相结合的方法优选木姜叶柯总黄酮分离纯化工艺。结果筛选出分离纯化效果最佳的聚酰胺树脂（80～100目）,其最佳工艺条件为：上柱根皮苷量（mg）与树脂（mL）的比例〈23∶1,上样液中根皮苷浓度为7.68 mg/mL,吸附流速为每小时1倍树脂体积（1 BV/h）,洗脱剂乙醇浓度为20%,洗脱流速为2 BV/h,洗脱剂用量为20 BV。纯化后木姜叶柯总黄酮的含量可达80%以上,根皮苷含量达65%以上。结论所优选的纯化工艺合理可行,可较好地分离纯化木姜叶柯总黄酮。