胆舒软胶囊的振动光谱分析

目的:建立鉴别中药材及其制剂中组分的分子振动光谱方法.方法:采用拉曼光谱法和红外光谱法鉴别胆舒软胶囊及对照品,测定胆舒胶囊中的薄荷素油的量,结果与气相法进行比较.结果:无论红外光谱还是拉曼光谱,胆舒软胶囊所呈现的峰均比对照品峰为多,但不干扰薄荷素油峰的鉴别,比较胆舒软胶囊和薄荷素油光谱,可快速鉴别胆舒软胶囊真伪.结论:建立的鉴别方法简便、快速、专属性强,灵敏度高.     

阿司匹林包合物的拉曼光谱和红外光谱研究

目的:通过拉曼光谱和红外光谱法分析阿司匹林包合物,探索拉曼光谱法作为一种新的验证包合物形成方法的可行性。方法:通过共聚焦拉曼光谱仪和傅里叶红外光谱仪分别测定并获得β-环糊精、阿司匹林、β-环糊精和阿司匹林物理混合物、阿司匹林包合物的拉曼图谱和红外图谱并将其进行对照分析。结果:在红外图谱和拉曼图谱中,阿司匹林的一些特征峰在其包合物中发生了位移,部分峰强发生变化甚至消失。结论:拉曼光谱和红外光谱同时表明,阿司匹林通过氢键作用嵌入β-环糊精的疏水空腔形成了包合物,其苯环结构、羰基结构和酯基结构被包裹于β-环糊精的空腔结构中。     

盐酸吗啡、咖啡因的FTIR检验及谱图解释

目的 提高用红外光谱法鉴定盐酸吗啡、咖啡因纯品、二者混合物的水平.方法 用红外光谱法有针对性地选择特征峰,探明盐酸吗啡、咖啡因红外光谱与结构的关系.结果 获得盐酸吗啡、咖啡因的特征峰.结论 该方法 克服了鉴定中的盲目性,重现性好,特异性强.     

拉曼光谱分析盐酸曲马多的结构特征

目的通过盐酸曲马多共聚焦拉曼光谱探讨其结构特征。方法用共焦拉曼光谱仪测定盐酸曲马多拉曼光谱图。结果所测药物图谱峰形良好,峰强明显,指纹性强,能够反映出盐酸曲马多的结构信息。结论共聚焦拉曼光谱仪可用于盐酸曲马多的结构特征分析,且拉曼光谱是一种简单、灵敏的光谱分析工具,有望成为药物分析中一种有效的鉴别手段。     

丙二醇与丙三醇红外光谱鬼峰的研究

目的：发现丙二醇与丙三醇红外光谱中鬼峰出现的缘由,建立方法去除鬼峰的干扰。方法：比较不同含水量样品的红外图谱膜法得到的红外光谱,分析鬼峰出现的原因;通过加热膜法控制鬼峰。结果：膜法制图1645cm^-1处有中等强度吸收峰,且含水量越高该峰强愈大;加热膜法制图该吸收峰消失或峰强显著降低。结论：鬼峰为水的吸收峰,采用加热膜法可避免鬼峰出现或有效控制鬼峰强度。     

拉曼光谱法直接测定甲硝唑片含量

目的 建立拉曼光谱法直接测定甲硝唑片含量的方法。方法 从便携式激光拉曼光谱仪的标准光谱图库中选出甲硝唑标准拉曼光谱图，再从甲硝唑标准拉曼光谱图(200～3 000 cm^–1)中筛选出适宜用于含量测定的特征峰，通过线性、重复性、回收率等方法学验证建立拉曼光谱直接测定甲硝唑片含量的方法，将甲硝唑片从药瓶中取出后直接用拉曼光谱法测定含量并将测定结果与HPLC测定结果做比较分析。结果 甲硝唑标准拉曼光谱图中1 533 cm^–1处的特征峰未受辅料干扰，专属性和稳定性最好，适宜用作含量测定的特征峰。拉曼光谱直接测定甲硝唑片含量的方法在26～1 000 mg·g^–1线性良好，线性方程为y=7.989 5x+0.394 8，相关系数为0.999 4；该方法的检测限和定量限分别为10和26 mg·g^–1。在高、中、低3个含量下，该方法的日内和日间精密度的RSD值分别为0.08%,0.12%,0.11%和0.47%,0.48%,0.65%。同一甲硝唑片重复测定6次的RSD值为0.41%。在回收率试验中，该方法测定高、中...     

振动光谱法研究对乙酰氨基酚固体分散体的分散性

目的:用拉曼和红外光谱法研究对乙酰氨基酚固体分散体的分散性,以期获得一种新的简单易行的检查固体分散体分散性的方法。方法:用溶剂-熔融法制备对乙酰氨基酚固体分散体,用显微共焦拉曼光谱仪和傅里叶变换红外光谱仪分别采集对乙酰氨基酚、PEG 6000、对乙酰氨基酚:PEG 6000(1∶5)的物理混合物以及对乙酰氨基酚固体分散体的拉曼光谱和红外光谱并进行对比分析。结果:对乙酰氨基酚与PEG 6000之间存在氢键效应,对乙酰氨基酚高度分散在PEG 6000中。结论:拉曼光谱法快速、直接、对样品无损伤,是一种新的理想的检查固体分散体分散性的方法。     

醛酮类药用辅料的振动光谱分析

目的:建立醛酮类药用辅料的拉曼光谱分析方法。方法:采集了几种醛酮类药用辅料的红外光谱和拉曼光谱,分别归属其振动光谱峰并分析比较光谱差异与结构之间的关系。结果:和红外光谱一样,拉曼光谱可以给出关于化合物结构的指纹信息,并可和红外光谱相互补充佐证。结论:建立的方法快速、简便、专属性强,可用于醛酮类药用辅料的鉴别。     

拉曼与近红外、中红外光谱在药品掺杂筛选应用中的前景分析

目的通过比较分析光谱法的原理、应用与药品快速检测需求,筛选最适合的快速检测信号采集方法。方法对比分析各类光谱定性分析基础、光谱数据信息采集手段、不同用户群的需求。结果红外、拉曼光谱比近红外光谱在定性鉴别方面更具优势,红外光谱可以作为实验室使用的初筛方法,拉曼光谱可以作为普筛方法使用。结论拉曼光谱为药品掺杂筛选一线首选信息采集方法。     

六氟异丙醇在难溶性多肽圆二色谱检测中的应用

二级结构是多肽药物发挥药理活性的重要基础,圆二色谱法是测定多肽二级结构最常用的方法,但一些难溶性多肽在检测中往往会遇到溶解度低和溶剂吸收干扰等困难。为了解决难溶性多肽在圆二色谱测定中溶剂选择的困难,文章从溶剂特性及原理出发,提出使用六氟异丙醇作为难溶性多肽的圆二色谱溶剂,并通过对多肽在纯六氟异丙醇及其与PBS混合溶剂的溶解实验和圆二色谱检测,验证了难溶性多肽在上述溶剂中溶解度较高,溶液均一且透明。CD图谱中多肽二级结构特征峰显著、稳定、结构信息充足,且未产生明显的溶剂吸收干扰。这些结果证明了六氟异丙醇可以作为难溶性多肽的良好溶剂,为其圆二色谱检测提供一种新的溶剂选择。     

Evaluation of a Raman Chemometric Method for Detecting Protein Structural Conformational Changes in Solution

Raman scattering shows promise as a powerful routine tool, to determine both secondary and the smaller tertiary structural changes that precede aggregation in both solutions and solids. A method was developed utilizing principal component analysis (PCA) of Raman spectra for detection of small, but meaningful, pH induced changes in tertiary protein structure linked to aggregate formation using α-lactalbumin solutions as a model. The sample preparation and spectral parameters, were optimized for a bulk Raman probe. Analysis of large regions (600–1850 cm^?1) yielded principal component (PC) scores useful for semi-quantitative comparison of protein conformation between formulations. PC loadings corresponded to specific structural peaks known to change with solution pH. PCA of circular dichroism (CD) spectra of dilute solutions yielded similar results. Sucrose is a common formulation excipient with a Raman spectrum that overlaps many protein peaks. With sucrose in the protein solution, the ability of PCA to discern protein structural changes from the Raman spectra was somewhat reduced. Analysis of a more limited spectral region (1530–1780 cm^?1) with negligible sucrose spectral contribution improved the discrimination of protein conformational states. The new Raman method accurately distinguished differences in protein structure in concentrated solutions. The long-term goal is to explore Raman characterization as a routine monitoring tool of protein stability in both solution and solid states.     

Physicochemical studies on the stability of influenza haemagglutinin in vaccine bulk material.

The relative unknown conformational stability of monovalent bulks of influenza virus haemagglutinin (HA) from three different strains (B/Guangdong, A/New Caledonia and A/Panama) was investigated with fluorescence and circular dichroism (CD) spectroscopy. Various stress conditions (concentration of denaturant, freeze-thawing, pH and temperature) affected the spectroscopic properties of the haemagglutinin proteins differently. Unfolding experiments revealed a poor stability of Guangdong haemagglutinin (GD-HA) in comparison with New Caledonia (NC-HA) and Panama haemagglutinin (P-HA). Freeze-thawing altered the secondary and tertiary structure of Guangdong haemagglutinin and only the tertiary structure of Panama haemagglutinin. From pH 4.6-9.2 the tertiary structures of Guangdong, New Caledonia and Panama haemagglutinin were all affected to a different extent. The secondary structure was only altered at low pH. Incubation of haemagglutinin at 60 degrees C resulted in denaturation of the protein and a dramatic change of the fluorescence spectrum, indicative of oxidised tryptophan (Trp). In conclusion, fluorescence and circular dichroism spectroscopy are highly suitable techniques to monitor the stability of haemagglutinin in a straightforward and fast way.     

食管癌组织Raman光谱的研究

目的探讨激光Raman光谱仪在检测食管癌组织和正常组织的Raman光谱差异，为临床医师早期诊断食管癌提供辅助手段。方法从临床手术获取新鲜组织后，利用激光Raman光谱仪，在激发光源波长为632．8nm照射下。检测食管癌组织和正常组织的Raman光谱。结果通过对食管癌组织和正常组织的激光Raman光谱分析，在64例食管癌组织的Raman光谱中，其中52例分别在波数为1661，9cm^-1和2936．7cm^-1附近均具有两个明显的特征峰，9例只在波数为2936．7cm^-1附近具有特征峰。3例无特征峰；而正常食管组织的激光Raman光谱在该范围内无明显可分辨的特征峰，只是一个平滑的曲线。结论找出不同食管组织Raman光谱的差异，这些差异可作为各类食管组织Raman光谱的特征。为激光Raman光谱技术应用于食管癌的早期诊断提供了重要的实验依据。     

头孢拉定中三种有关物质的表面增强拉曼光谱研究

摘 要 目的:研究头孢拉定中三种有关物质的拉曼光谱及表面增强拉曼光谱, 对三种目标物在不同酸碱条件下的表面增强拉曼光谱进行分析。方法: 用便携式拉曼光谱仪对三种物质的常规拉曼光谱与不同酸碱条件下的表面增强拉曼光谱进行考察,并参照头孢拉定有关物质与主成分实际比例模拟实验,测定了不同条件下头孢拉定的有关物质。 结果: 三种物质均能在表面增强拉曼光谱中表现出跟常规拉曼光谱相对应的特征峰信息,酸碱度对于三种物质表面增强拉曼光谱的检测均有一定的影响。在体系偏酸性的条件下可实现头孢氨苄与7 氨基去乙酰氧基头孢烷酸的同时检出,偏碱性的条件下光谱表现为头孢氨苄的特征峰;而双氢苯甘氨酸在两种pH条件下的光谱特征性都不明显。结论: 头孢拉定有关物质的表面增强拉曼光谱体现出一定的指纹性特征,可用表面增强拉曼光谱对头孢拉定有关物质进行初步鉴别。     

Circular dichroism and fluorescence spectroscopic analyses of a proline-rich glycoprotein from human parotid saliva

A proline-rich glycoprotein (PRG) was isolated from human parotid saliva and examined by circular dichroism and fluorescence spectroscopy. Addition of guanidine hydrochloride to PRG labeled with an extrinsic dansyl probe had no effect on the fluorescence spectra's 511 nm lambda-max location. Thermodynamic calculations supported the contention that PRG has no significant tertiary structure. Circular dichroism results for PRG were simulated by computer and a secondary structure composed of 70% random coil and 30%β-form conformation was predicted. Circular dichroism of PRG failed to detect either poly-L-proline type I or II structures. Deglycosylation of PRG had no measurable effect on the circular dichroism spectrum, indicating that the carbohydrate side chains had little influence on PRG secondary structure. Based upon mathematical calculations, β-turns were predicted around three glycosylated Asn residues of PRG. These collective data suggest that PRG is composed of a disordered polypeptide chain with at least three of the N-linked Asn residues participating in some type of β-turn.     

EFFECT OF TEMPERATURE UPON THE CIRCULAR DICHROISM OF BRADYKININ

Analysis of the effect of temperature on the circular dichroism spectrum of bradykinin has led to a more precise understanding of the solution conformation of the peptide. Circular dichroism and ¹³C n.m.r. have been used in a complementary fashion to support the picture that bradykinin spends a maximum of about 20% of its time in a partially ordered conformation featuring a γ-turn with Pro⁷ as the second residue. Since the γ-turn probability is insensitive to temperature, some other conformational effect dominated by the structure of water presumably produces the pronounced change in the circular dichroism spectrum with increasing temperature.     

Purification and conformation of ribosomal protein L25 from E. coli ribosome

Ribosomal protein L25 from the large subunit of E. coli ribosomes has been purified using a new procedure involving a 2 m LiCl extraction followed by phosphocellulose chromatography in 6 m urea elution buffer. The conformation of purified L25 was studied employing circular dichroism and ultraviolet absorption spectroscopy in reconstitution buffer. The analysis of the far u.v. circular dichroism spectrum of L25 indicates L25 contains ～ 16%α-helix and ～ 19%β-structure. The conformation of L25 was also studied using the predictive methods of Chou & Fasman and Maxfield & Scheraga. Both of these methods predict approximately three times the percent α-helix present in L25 as compared with that determined from the analysis of the circular dichroism spectrum. A structure for L25 is predicted which contains two positively charged binding domains and is consistent with published binding data on the interaction of 5S RNA and L25. The large difference in the %α-helix as determined from the analysis of the circular dichroism spectrum and the predictive techniques is suggested to result from the denaturing effects of 6 m urea used in the preparation of ribosomal proteins.     

Argutalactone, an unprecedented sesquiterpenoid lactone with a 6/5/7 tricyclic system from Incarvillea arguta

Argutalactone (1), a novel sesquiterpenoid lactone featuring an unprecedented 6/5/7 rigid skeleton, was isolated from the roots of Incarvillea arguta. The structure and relative configuration of 1 were established by extensive analysis of spectroscopic data. The absolute configuration of 1 was determined as 2R,5S,10R,12S based on the analysis of biogenetical transformation, comparison of the optical rotation with literature data, and comparison of the experimental circular dichroism spectrum with the calculated electronic circular dichroism spectra.     

丹参素的抗癌活性研究

目的：建立体外抗癌天然药物筛选模型,评价丹参素的抗癌活性。方法：以遗传物质DNA为靶标,溴化乙锭（EB）为致癌物质,丹参素为试药,利用荧光光谱检测丹参素对EB-DNA体系的荧光猝灭效应;利用圆二色谱技术检测丹参素对EB-DNA体系的干扰作用。结果：丹参素能明显抑制EB-DNA体系的荧光强度,且具有浓度依赖性;丹参素能够有效阻断EB嵌入DNA的碱基对中,维持DNA分子的正常构象。结论：丹参素抑制致癌剂对DNA链的嵌合,从而起抗癌活性。该模型可应用于抗癌功效的天然药物的筛选中。