维生素B_1对蘑菇酪氨酸酶抑制作用机理的研究

报道了维生素B1对蘑菇酪氨酸酶的单酚酶和二酚酶活力的影响以及抑制作用机理.研究结果表明,维生素B1(Vit B1)对蘑菇酪氨酸酶的单酚酶和二酚酶活性均有抑制作用.测定导致单酚酶活力和二酚酶活力下降50%的抑制剂浓度(IC50)分别为15和20 mmol/L.Vit B1对蘑菇酪氨酸酶的单酚酶的迟滞时间有明显的延长效应,21 mmol/L Vit B1使得单酚酶的迟滞时间从52 s延长到277 s.Vit B1对二酚酶的抑制作用表现为竞争性抑制类型,测定抑制常数(KI)为11.7 mmol/L

Lica光激化学发光免疫分析系统检测乙肝两对半的性能评价

目的对Lica光激化学发光免疫分析系统主要性能进行初步评价。方法以美国临床实验室标准化协会(CLSI)制定的评价标准,通过一系列实验设计,对Lica光激化学发光免疫分析系统进行乙肝"两对半"检测的精密度、准确度、线性、分析灵敏度等进行评价。结果 Lica光激化学发光免疫分析系统进行乙肝"两对半"检测,批内不精密度变异系数在1.49%～4.40%,总不精密度在2.15%～6.22%,回收试验的回收率为96.32%～106.54%,HbsAg、Anti-HBs、HBeAg、Anti-HBe、Anti-HBc的分析灵敏度分别为0.04ng/mL、1.72mIU/mL、0.09PEIU/mL、0.31PEIU/mL、0.02PEIU/mL。结论 Lica光激化学发光免疫分析系统各方面性能良好,测定样本快速、准确、精密可靠,能适应医院日常样本的检测需要

Capillary Electrophoretic Separation of Enantiomorphs of Shikimic Acid

采用毛细管电泳分离莽草酸及其对映体。试验了缓冲溶液的种类、浓度、pH值、分离电压、进样时间、添加剂对分离的影响。结果表明:以30mmol·L-1三(羟甲基)氨基甲烷-30mmol·L-1 H3BO3(pH8.6)为缓冲体系,在波长214nm,分离电压为15kV,进样时间为10s的条件下,实现了对莽草酸及其对映体的分离。High performance capillary electrophoresis was applied to the separation of enantiomorphs of shikimic acid. Several important factors influential to the separation i. e- pH and concentration of the running buffer solution, working voltage of separation, time of sample introduction and the use of additives, were studied and optimized. Enantiomorphs of shikimic acid were separated satisfactorily under the follwing optimized conditions： （2） running buffer solution： 30 mmol·L^-1 Tris·HCl＋30 mmol·L^-1 H3BO3 （pH 8. 6）; （2） working voltage of separation.. 15 kV; （4） wavelength of UV-detection： 214 nm; （4） time of sample introduction： 10 s.广西自然科学基金项目(桂科自:0236037； 桂科自:0640038)资

溴麝香草酚蓝比色法测定叶下珠生物碱的含量

目的测定叶下珠中总生物碱的含量。方法以溴麝香草酚蓝为显色剂于415 nm波长处测定吸光度。结果苦参碱在0.004~0.02 mg/m l范围内线性关系良好(r=0.997 54);其与溴麝香草酚蓝所形成的离子对产物在6 h内稳定;平均加样回收率为98.65%(RSD=1.98%)。结论该方法简单、快速、准确,可用于生药及产品的生物碱质量控制。广西自然科学基金项目资助(No.0640038

Ion Chromatography for Content Determination of Various Phosphate Forms in Tripolyphosphate

研究了离子色谱法测定食品添加剂三聚磷酸盐中不同形态磷酸盐含量的方法。用NaOH溶液梯度淋洗,选用1.0ml/min的流速,成功测定了三聚磷酸盐中各组分(正磷酸盐、焦磷酸盐、三聚磷酸盐和三偏磷酸盐)的含量。各磷酸盐在测定条件下有很好的线性范围,检测限(S/N=3)为0.010～0.063mg/L,保留时间的相对标准偏差为0.38%～0.79%,峰面积的相对标准偏差为2.21%～6.96%,样品的加标回收率为97.45%～106.89%,整个分析过程可在10min内完成。实验结果表明,该方法具有分析时间短、灵敏度高、线性范围宽、试剂用量少等优点。 An ion chromatography method was developed for determination of contents of various phosphate forms in tripolyphosphate, in the present study. Phosphates were eluted with100 mmol/L NaOH solution in gradient at a flow rate of 1.0 ml/ min. The method presented good linearities between the peak areas and concentrations of orthophosphate, pyrophosphate, tripolyphosphate, and trimetaphosphate and their detection limit ranged from 0.010 to 0.063 mg/L. The relative standard deviations （RSD） of the retention time varied between 0.38% and 0.79% and the RSD of the peak area was between 2.21% and 6.96%. The recoveries of the above phosphates in spiked tripolyphosphate sample ranged from 97.45% to106.89%. This complete analysis procedure lasted 10min. Our results indicated that this method is rapid and accurate with a wide linear range and less consumption of chemicals.广西科学基金项目(桂科回:0144001

Application of Capillary Electrophoretic Finger Print Atlas to the Determination of Flavones in the TCM of Phyllanthus Urinarial

建立了叶下珠药材中黄酮的毛细管电泳指纹图谱。以硼砂和十二烷基磺酸钠(pH9.0)为背景电解质溶液,运行电压15kV,紫外检测波长245nm,流体静压力进样15s(高度12cm),对不同产地叶下珠药材进样检测。按电泳峰共有率fi≥70%为依据,确定10个不同产地叶下珠药材中黄酮的毛细管电泳指纹峰为8个,各产地叶下珠的毛细管电泳指纹图谱与标准毛细管电泳指纹图谱的相似度较好。在制备供试液后不同时间进样测定,各指纹峰的相对迁移时间的相对标准偏差小于5%,相对峰面积的相对标准偏差在3.0%～7.8%之间,结果表明样品在48h内稳定。The electrophoretic finger print atlas of flavones in the TCM of phyllanthus urinarial was established by capillary electrophoresis. A mixture of 60 mmol · L^-1 borax solution and 16 mmol · L^-1 sodium dodecyl sufate solution （adjusted to pH 9 with 0. 1 mmol · L^-1 boric acid solution preliminarily） was used as background electrolyte, and moving voltage of 15 kV was applied. UV-detection at the wavelength of 245 um was adopted- Samples were introduced hydrostatically at a height of 12 cm for 15 s. Samples of phyllanthus urinarial grown in 10 different areas were taken for analysis. Base on the value of rate of common electrophoretic peaks fi≥ 70%, a set of electrophoretic finger print atlas of 8 peaks was determined for flavones in phyllanthus urinarial samples from 10 different areas in our country. Good similarities between the eleetrophoretie finger print atlases of the samples and the standards were obtained. Relative standard deviation among the values of relative migration times of various finger print peaks obtained at different time of sample introduction was less than 5 %, and values of RSD＇s for the relative peak areas were in the range from 3. 0% to 7. 8%. The results obtained proved that the sample was stable within 48h.广西自然科学基金项目(桂科自:0640038)资