光谱法研究顺铂与溶菌酶的相互作用

目的:研究顺铂与溶菌酶相互作用的光谱学特征。方法:应用光谱法研究顺铂与溶菌酶的相互作用机制;计算其结合常数、结合位点数和结合距离;根据热力学参数判断作用力类型;考察二者的相互作用对溶菌酶构象的影响。结果:顺铂对溶菌酶的荧光淬灭过程为生成复合物的静态淬灭;供能体与受能体之间的距离小于7nm,发生了非辐射能量转移;二者以氢键和范德华力结合为主;同步荧光光谱和三维荧光光谱表明结合反应影响了氨基酸残基所处的微环境。结论:顺铂能与溶菌酶结合并改变溶菌酶的构象。     

药物与溶菌酶相互作用的研究进展

药物发挥疗效主要是通过与体内疾病相关的生物大分子作用,影响或改变后者的生物学功能,从而产生防治疾病的效果。药物与生物大分子作用的方式和亲和力的大小是其发挥活性的一个重要方面。因此,研究药物与生物大分子的相     

牡荆苷与溶菌酶相互作用的荧光光谱学研究

目的在模拟人体生理条件下,研究牡荆苷与溶菌酶的相互作用的光谱学特征。方法利用同步荧光光谱法和荧光光谱法研究牡荆苷与溶菌酶的相互作用机制、作用力类型,考察牡荆苷对溶菌酶构象的影响。结果牡荆苷对溶菌酶的荧光猝灭机制为静态猝灭,牡荆苷与溶菌酶的结合常数、结合位点数分别为6.73×10~5 L/mol、1.12,其作用力以疏水作用为主。同步荧光光谱法测定的结合位点靠近色氨酸,并使色氨酸的疏水性增强。结论牡荆苷与溶菌酶结合并改变溶菌酶的构象,共存金属离子对牡荆苷与溶菌酶的相互作用有一定的影响。     

光谱法和分子对接法研究盐酸雷尼替丁与溶菌酶的相互作用

目的 用荧光光谱法、紫外光谱法和分子对接研究生理条件下盐酸雷尼替丁与溶菌酶相互作用的光谱特性,为盐酸雷尼替丁的体内代谢过程提供一定的理论依据.方法 在激发波长(λex)282 nm条件下,测定盐酸雷尼替丁与溶菌酶在不同温度下的荧光猝灭光谱;使用Stern-Volmer曲线方程判断猝灭机制;计算其结合常数(K)、结合位点...     

一测多评法测定藏茴香中异绿原酸A、新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸C

目的 建立一测多评法（QAMS）测定藏茴香中6种咖啡酰奎宁酸类成分含量,并验证该方法在藏茴香质量评价中应用的可行性与适用性。方法 取藏茴香粉末（过三号筛）0.5 g,精密加入70%甲醇 20 mL ,超声处理（250 W、频率 53 kHz）30 min,制备供试品溶液;采用Phenomenex GeminiR C₁₈（250 mm×4.6 mm,5 μm）色谱柱,以乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,检测波长为 330 nm,体积流量 1.0 mL·min^-1,柱温 30 ℃,进行专属性、供试品提取条件、检测波长选择、色谱条件、线性关系、精密度、重复性、稳定性、加样回收率方法学考察,建立异绿原酸A、新绿原酸、绿原酸、隐绿原酸、异绿原酸 B、异绿原酸 C成分含量检测的 HPLC法;以异绿原酸 A为内参成分,分别计算新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸C 5种成分的相对校正因子,分别采用3种不同色谱仪和3种色谱柱进行相对校正因子、相对保留时间耐用性考察,对藏茴香样品同时采用外标法与 QAMS 测定 6 种成分的质量分数,比较 2 种测定方法结果的差异。结果 建立的6种成分的HPLC检测方法的专属性、供试品提取条件、检测波长选择、色谱条件、线性关系、精密度、重复性、稳定性、加样回收率均符合要求;新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸C的相对校正因子平均值分别是 1.362、1.257、1.335、1.470、1.134,3种不同色谱仪和 3种色谱柱对相对校正因子、相对保留时间均无明显影响;QAMS与外标法2种方法测定3批藏茴香样品中6种成分得到的结果之间无显著差异。结论 建立的QAMS简便、准确、可靠,可用于藏茴香中6种咖啡酰奎宁酸类成分——异绿原酸A、新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸C的定量分析。     

西尼地平与人血清白蛋白相互作用的荧光光谱法研究

本文采用荧光分光光度法研究了西尼地平与人血清白蛋白(HSA)间的相互作用。根据Stern-Volmer方程确定了西尼地平对人血清白蛋白的猝灭类型为静态猝灭。通过计算求得生理条件下(pH=7.4)西尼地平与HSA的结合常数为3.3×105,结合位点数为1.24。实验考察了pH及微量金属离子对药物与HSA相互作用的影响。最后根据热力学方法确定了该药物与人血清白蛋白之间的作用力类型为静电作用力。     

荧光光谱法研究忍冬苷与牛血清白蛋白的相互作用

本文首次采用荧光光谱法研究了忍冬瞢与牛血清白费白（BSA）在模拟人体生理条件下的相互作用。结果表明忍冬苷对BSA的荧光猝灭作用属于静态猝灭．且296K下结合常数Ka为3．82×10^-5L·mol^-1,结合位点数n为1．16;热力学分析表明二者主要靠氢键和范德华力结合;位点竞争实验则显示忍冬苷主要通过Site I与BSA相结合;最后还考察了几种常见的共存离子对相互作用的影响。     

荧光光谱法研究青蒿素及双氢青蒿素与肝微粒体的相互作用

目的研究抗疟药青蒿素(ART)与双氢青蒿素(DHA)和大鼠肝微粒体(RLM)以及人肝微粒体(HLM)之间的相互作用。方法在模拟人体生理条件下,采用荧光光谱法,得出青蒿素、DHA与RLM和HLM的结合参数。结果青蒿素和DHA对RLM和HLM的猝灭机制不同,它们对RLM的猝灭机制均为静态猝灭,而对HLM的猝灭作用为混合猝灭;其相互间作用力均为氢键和范德华力,其结合反应均为自发的热力学反应。结论青蒿素和DHA对大鼠和人肝微粒体均有结合,且结合力存在种属差异,同时青蒿素和DHA与同种肝微粒体的结合能力也存在差异。     

荧光光谱法研究盐酸黄连素与乙烯吡咯烷酮的相互作用

采用荧光光谱法研究了盐酸黄连素（Ber）与乙烯吡咯烷酮（VP）在水溶液中的相互作用。结果表明：乙烯吡咯烷酮的包合作用导致盐酸黄连素Ber荧光强度减弱而其峰值波长基本不变，并证实形成了1：1包合物；测定了它在不同温度下的包合形成常数Kf及其热力学函数。     

荧光光谱法研究安非他酮与人血清白蛋白的相互作用

目的 研究安非他酮与人血清白蛋白(human serum albumin,HSA)的相互作用。方法 通过荧光光谱法研究安非他酮对HSA的荧光猝灭光谱和同步荧光光谱的影响。由Stern-Volmer方程确定安非他酮对HSA的荧光猝灭机制,双对数方程确定反应结合位点和结合常数。根据热力学方程讨论两者间主要的作用力类型。结果 荧光猝灭光谱显示,安非他酮对HSA有猝灭作用,在17 ℃和37 ℃时的猝灭速率常数分别为5.714 8×10³和3.126 1×10³ L·mol^-1·s^-1,反应前后的焓变和熵变均<0,结合点数为1。结论 安非他酮对HSA的猝灭过程为静态猝灭,二者间的结合力主要为氢键和范德华力。     

Spectroscopic studies on the interaction between erlotinib hydrochloride and bovine serum albumin

Background and the purpose of the study

The binding ability of a drug to serum albumin has influence on the pharmacokinetics of a drug. In the present study, the mutual interaction of anticancer drug erlotinib hydrochloride with bovine serum albumin (BSA) using fluorescence and UV/vis spectroscopy was investigated.

Methods

The BSA solution (0.1 mM) was prepared daily in Tris buffer (0.05 mol l-1, pH =7.4) and treated at final concentration of 1.67×10-5 M with different amounts of erlotinib hydrochloride to obtain final concentrations of 0, 0.2, 0.4, 0.8, 1, 2, 4, 6, 8, 20 and 42 µM receptively. The mixture was allowed to stand for 5 min and the fluorescence quenching spectra were recorded at 298, 303, 308 and 313 K.

Results

It was found that erlotinib hydrochloride caused the fluorescence quenching of BSA by the formation of a BSA-erlotinib hydrochloride complex. The mechanism of the complex formation was then analyzed by determination of the number of binding sites, apparent binding constant K, and calculation of the corresponding thermodynamic parameters such as the free energy (△G), enthalpy (△H) and entropy changes (△S) at different temperatures. Results showed that binding of erlotinib hydrochloride to BSA was spontaneous, and the hydrophobic forces played a major role in the complex formation. The distance, r, between donor (BSA) and acceptor (erlotinib hydrochloride) was found to be less than 8 nm suggesting the occurrence of non-radiative energy transferring and static quenching between these two molecules.

Conclusion

The results provided preliminary information on the binding of erlotinib hydrochloride to BSA and the presence of a single binding site on BSA and K values for the association of BSA with erlotinib hydrochloride increased by the increase in temperature.     

HPLC测定风热清胶囊中的绿原酸和牛磺熊去氧胆酸

目的建立测定风热清胶囊中绿原酸和牛磺熊去氧胆酸的方法。方法采用HPLC法,绿原酸的测定用Kromasil C18柱(150 mm×4.6 mm,5μm),流动相为乙腈-0.4%磷酸溶液(9:91),流速为0.8 m.lmin-1,柱温为35℃;牛磺熊去氧胆酸的测定用Phenomenex双子星C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.03 mo.lL-1磷酸二氢钠溶液(65:35)(磷酸调pH4.4),流速为0.8 ml.min-1,柱温35℃。结果绿原酸进样量0.3176~2.3820μg与峰面积的线性关系良好(r=0.9999),平均回收率为103.82%,RSD=0.30%;牛磺熊去氧胆酸进样量0.2036~1.6288μg与峰面积的线性关系良好(r=0.9999),平均回收率为98.72%,RSD=0.98%。结论所用方法简便可行、重复性好,可控制风热清胶囊的质量。     

RP-HPLC法测定蒲公英中绿原酸与咖啡酸的含量

目的测定蒲公英中绿原酸与咖啡酸的含量。方法采用Diamonsil C18色谱柱,流动相为乙腈-磷酸二氢钠缓冲液(13∶87,v/v),检测波长323 nm。结果绿原酸在2.4~48.0μg/mL(r=0.999 5),咖啡酸在1.0~20.0μg/mL(r=0.999 7)线性关系良好,咖啡酸、绿原酸的平均回收率分别为99.7%(RSD=0.8%)和100.8%(RSD=1.1%)。结论该方法准确、可靠、重现性好,可作为控制蒲公英药材质量的方法。     

西南地区有柄石韦UPLC指纹图谱的建立及酚酸类成分的测定

目的:建立西南地区有柄石韦的超高效液相色谱(UPLC)指纹图谱,并测定其中4种酚酸类成分(新绿原酸、咖啡酸、绿原酸、隐绿原酸)的含量.方法:采用Waters Cortecs T3 C18(100 mm×2.1 mm,1.6μm)色谱柱,以甲醇-0.1％磷酸溶液为流动相进行梯度洗脱,流速为0.35 mL/min,检测波长...     

Spectroscopic studies on the interaction between silicotungstic acid and bovine serum albumin

The interaction between silicotungstic acid and bovine serum albumin (BSA) was investigated using fluorescence and UV/vis. The experimental results showed that the fluorescence quenching of BSA by silicotungstic acid is a result of the formation of SiW–BSA complex; static quenching and non-radiative energy transferring were confirmed to result in the fluorescence quenching. The binding site number n, apparent binding constant K_A and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BSA was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic interaction force plays a major role in stabilizing the complex. The effect of silicotungstic acid on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.     

Multiple spectroscopic studies on the interaction between olaquindox,a feed additive,and bovine serum albumin

The interaction between olaquindox (OLA) and bovine serum albumin (BSA) was investigated using fluorescence, UV–vis absorption and circular dichroism (CD) spectroscopy. The results showed that the fluorescence quenching of BSA by OLA was a static quenching process induced by the formation of OLA–BSA complex. The binding constant of OLA–BSA complex was calculated to be 1.299 × 10⁴ L mol⁻¹ (293 K). The negative values of ΔH⁰ and ΔS⁰ indicated that hydrogen bond and van der Waals interactions played major roles in stabilizing the complex. Site probe competition experiments and number of binding sites (n) revealed that OLA could bind to site I in subdomain IIA of BSA, and the binding distance (r) was evaluated to be 3.643 nm according to Förster’s non-radiative energy transfer theory. The results of CD and three-dimensional fluorescence spectra suggested some conformational changes of BSA after OLA binding.     

Effects of chlorogenic acid and its metabolites on the sleep-wakefulness cycle in rats

The effect of chlorogenic acid on the sleep-wakefulness cycle in rats was investigated in comparison with those of caffeic acid (the metabolite of chlorogenic acid) and dihydrocaffeic acid (the metabolite of caffeic acid). A significant prolongation of sleep latency was observed with chlorogenic acid and caffeic acid at a dose of 500 and 200 mg/kg, respectively. On the other hand, no remarkable effects were observed with dihydrocaffeic acid even at a dose of 500 mg/kg. Caffeine caused a significant increase in sleep latency and waking time and decrease in non-rapid eye movement sleep time at a dose of 10 mg/kg. In contrast, chlorogenic acid and its metabolites had no significant effects on each sleep state. From these results, it may be concluded that chrologenic acid caused a mild arousal effect compared with that of caffeine, and the effect of chlorogenic acid may have occurred through its metabolite caffeic acid.     

绿原酸缀合物HA-CGA的抗菌活性研究

目的 合成透明质酸(HA)-绿原酸(CGA)的水溶性缀合物HA-CGA并对其结构进行表征,并比较该缀合物与单体药物CGA的抗菌活性。方法 将HA溶于水中,用1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC·HCl)将其活化,然后加入溶于DMF的CGA进行酯化反应,最后将反应溶液在水中透析除杂,冻干,得到缀合物HA-CGA,并采用核磁共振氢谱法、红外光谱法对HA-CGA结构进行表征;采用平板计数法来比较CGA和HA-CGA对大肠埃希菌、金黄色葡萄球菌等2种细菌的抑制作用。结果CGA和HA-CGA对2种细菌均有不同程度的抑制作用,其中HA-CGA抗菌活性强于CGA。结论 通过HA对CGA的结构进行修饰,增加了CGA的水溶性,进一步提高了CGA的抗菌性能。     

RP-HPLC测定宁夏原周区金银花中绿原酸含量的动态变化

目的研究宁夏原周区金银花中绿原酸含量的动态变化。方法采用RP-HPLC法测定。结果绿原酸的含量在六月份最高,九月份最低。同一天内,以上午10.00~12.00采收的含量最高。结论若以绿原酸含量为指标,金银花以六月份为最佳采收期,且在上午10.00~12.00采收为佳。