胶束溶液中钙黄绿素-荧光桃红间荧光共振能量转移的研究及应用

研究了钙黄绿素-荧光桃红体系的荧光共振能量转移机理及其在蛋白质测定中的应用.实验表明:在聚乙烯醇存在下,于HAc-NaAc缓冲液(pH 5.30)中,钙黄绿素与荧光桃红之间能发生有效的能量转移.根据Frster理论,探讨了钙黄绿素与荧光桃红分子间能量转移机理.结果表明:蛋白质的加入使钙黄绿素-荧光桃红体系发生荧光猝灭...     

基于钙黄绿素－臧红T荧光共振能量转移检测六偏磷酸钠

在pH8．5的Tris－HCl缓冲溶液中,钙黄绿素作为能量供体（D）可以与藏红T受体（A）发生有效的荧光共振能量转移（FRET）,但加入六偏磷酸钠（SHMP）后,因其与受体发生静电作用破坏了该能量转移体系,使得荧光供体钙黄绿素荧光强度的增加（△FD）与受体藏红T荧光强度的降低（△FA）的比值（△FD／△R）-9SHMP浓度（csHMP）呈良好的线性关系．基于此,建立了一种检测六偏磷酸盐的新方法．在优化条件下,该方法的检测范围为3．0×10^-6-1．0×10^-5mol／L,对6．0×10拍mol／L的六偏磷酸盐连续平行测定11次,其相对标准偏差（RSD）为3．1％．该方法具有选择性好、操作简单和检测速度快等优点,已成功应用于饮料中六偏磷酸钠的分析检测．     

荧光共振能量转移测定杀虫单

1引言 研究了钙黄绿素（Calcein）与酚藏花红（PF）的荧光共振能量转移现象，并且将其作为探针用来测定杀虫单，扩大了荧光共振能量转移的应用领域。该方法准确、简便，灵敏度高，检出限低，同时能消除仪器噪音影响，结果令人满意。     

DNA荧光探针—荧光素-中性红体系的研究

基于DNA对荧光素(FL)-中性红(NR)分子间荧光能量转移的抑制作用，以荧光素-中性红为荧光探针，考察该探针与DNA的结合反应，建立了准确测定DNA的新方法，在pH＝6.5条件下，hsDNA、ctDNA和smDNA的浓度与荧光素-中性红体系的荧光比值变化量Δ(Fd／Fa)成线性关系，响应线性范围分别为0．25-6．25μg／mL、0．10-5．00μg／mL、0．10-4．00μg／mL，0.025μg/mL和0．023μg／mL；分析测定了DNA合成样品，回收率91．3％-101．4％，相对标准偏差小于4．2％．     

光导纤维荧光法测定水中的痕量氰化物

钙黄绿素的水溶液在pH6—10范围内有很强的荧光发射,pH9—10时最大激发波长为500nm,最大发射波长为520nm。钙黄绿素能与铜离子形成络合物使荧光淬灭,而氰根却又能从钙黄绿素和铜的络合物中置换出钙黄绿素,使荧光重新显现。据此,Ryan等人曾利用这一性质实现氰根的定量测定,检测下限为10ppb。本文研究了少量抗坏血酸对钙黄绿素-铜-氰根体系的荧光显著增强作用,使测定氰根的灵敏度提高一个数量级以上,检测下限     

钙黄绿素-刚果红荧光光度法测定片剂及尿液中莫西沙星含量

在pH6.0的Britton-Robinson(B-R)缓冲溶液中,刚果红与钙黄绿素能够发生有效的能量转移,使钙黄绿素荧光猝灭.莫西沙星的加入,又使得钙黄绿素重现荧光,据此建立了测定莫西沙星的新方法.将该方法用于片剂和尿液中莫西沙星的测定,结果满意.实验表明,该方法简单、快速、灵敏、准确.     

钙黄绿素蓝荧光猝灭测定茶叶中的锰

本文研究了Ｍｎ（Ⅱ）－钙黄绿素蓝的荧光体系的测定方法及条件，在ＰＨ９．５－１０．０的硼砂－氢氧化钾缓冲溶液中，钙黄绿素蓝的λｅｘ为３６２ｎｍ，λｅｍ为４４６ｎｍ，Ｍｎ（Ⅱ）与钙黄绿素蓝生成的１：１络合物猝灭钙黄绿素蓝的荧光。锰量的线性范围为０．０５－１．０μｇ／１０ｍＬ，方法灵敏度高，检测限为５ｎｇ／ｍＬ。该方法用于茶叶中锰的测定，结果满意。     

微顺序注射-钙黄绿素荧光猝灭法测定利福平

在碱性条件下,利福平对钙黄绿素产生的化学发光信号具有显著的抑制作用,据此结合微顺序流动注射分析技术,建立了快速测定利福平的微顺序注射-钙黄绿素荧光猝灭方法。在碱性介质中,钙黄绿素浓度为33.33μg/m L时其发光强度达到最大值;在此实验条件下,利福平在20.64~103.2μg/m L范围内与钙黄绿素荧光猝灭强度呈良好的线性关系,方程为I_F=-192.57ρ+44624(r=0.9997)。     

金纳米粒子-钙黄绿素荧光共振能量转移体系测定青霉胺

利用金纳米粒子-钙黄绿素荧光共振能量转移体系,建立了一种简单、灵敏、快速测定药物青霉胺的方法。初步探讨了方法机理,并对体系pH、反应时间、Au NPs和钙黄绿素的浓度等实验条件进行了优化。优化实验条件下,方法的线性范围为1. 87×10~(-7)~1. 68×10~(-5)mol·L~(-1),检出限(3S/N)为6. 87×10~(-8)mol·L~(-1)。该法用于青霉胺药品中青霉胺的测定,结果满意。     

钙黄绿素-钯（Ⅱ）荧光光度法测定土壤中甲拌磷残留

基于钙黄绿素在pH 6.4的NaoH-KH2PO4缓冲溶液中有荧光,钯(Ⅱ)与钙黄绿素反应使其荧光猝灭,甲拌磷与钙黄绿素-钯(Ⅱ)反应置换出钙黄绿素,重显荧光,分别以493 nm和514 nm为激发波长和发射波长,建立了一种测定甲拌磷的新方法.方法的线性范围为2.0×10-5～2.0×10-7mol·L-1,相关系数为0.9988,检出限为5.3×10-9mol·L-1.用该法对土壤样品进行分析,并与色谱法对照,结果比较满意.     

AFM‐Correlated CSM‐Coupled Raman/Fluorescence Studies on Selective Interactions of Water Soluble Porphyrins with DNA

The Raman and fluorescence spectroscopic properties of water‐soluble oxo‐titanium(IV) mesotetrakis (1‐methyl pyridium‐4‐yl) porphyrin (O=Ti(TMPyP)⁴⁺) bound with calf thymus DNA and artificial DNAs such as double stranded poly[d(A‐T)₂] and poly[d(G‐C)₂] have been investigated on the single DNA molecule basis by AFM‐correlated confocal scanning microscope (CSM)‐coupled Raman and fluorescence spectroscopic techniques as well as the ensemble‐averaged spectroscopy. The ensemble‐averaged spectroscopic studies imply that the porphyrin interacts with DNA in different groove binding patterns depending on the base pairs. AFM‐images of the different DNAs bound with O=Ti(TMPyP)⁴⁺ were measured, and their morphologies are found to depend on kind of base pairs interacting with O=Ti(TMPyP)⁴⁺. Being correlated with the AFM images, the CSM‐coupled Raman and fluorescence spectral properties of the three different single O=Ti(TMPyP)⁴⁺‐DNA complexes were observed to be highly resolved and sensitive to base pair‐dependent axial ligation of Ti‐O bond as compared to the corresponding ensemble‐averaged spectral properties, which affect the groove binding and its strength of the O=Ti(TMPyP)⁴⁺ with DNA. The axial ligation was found to be accompanied by vibration structural change of the porphyrin ring, leading to keep the shape of double stranded poly[d(A‐T)₂] rigid while poly‐[d(G‐C)₂] and calf thymus DNA flexible after binding with the oxo‐titanyl porphyrin. The base pair dependence of the fluorescence decay times of the DNA‐bound porphyrins was also observed, implying that an excited‐state charge transfer takes place in the G‐C rich major groove in calf thymus DNA. These results suggest that binding of O=Ti(TMPyP)⁴⁺ is more preferential with the G‐C rich major groove than with the A‐T rich minor groove in calf thymus DNA so that the morphology of DNA is changed.     

Electronic excitation energy transfer between nucleobases of natural DNA

Transfer of the electronic excitation energy in calf thymus DNA is studied by time-resolved fluorescence spectroscopy. The fluorescence anisotropy, after an initial decay starting on the femtosecond time scale, dwindles down to ca. 0.1. The in-plane depolarized fluorescence decays are described by a stretched exponential law. Our observations are consistent with one-dimensional transfer mediated by charge-transfer excited states.     

光谱法研究盐酸小檗碱与DNA的相互作用

采用荧光和紫外(UV)光谱等手段,研究了中药有效成分小檗碱(Ber)与脱氧核糖核酸(DNA)的键合作用。结果发现,小檗碱能插入到DNA双螺旋碱基对之间的空腔中,使小檗碱在eλm=530 nm处较弱的荧光强度显著提高;酸度显著影响其相互之间的作用;随着DNA浓度的增大,Ber的荧光强度增大,显示了很好的光敏性能。偏振、荧光猝灭实验等也进一步表明:Ber与DNA的作用方式主要是嵌插结合;离子强度的大小会影响Ber与DNA之间的作用。在pH=3.0适宜酸度条件下,建立了以Ber为探针定量测定DNA的分析方法。方法线性范围为0~5.2×10-5mol/L,精密度(RSD)为2.7%(n=7),检出限为1.43×10-7mol/L。     

Fluorescence energy transfer between Acridine Orange and Safranine T and its application in the determination of DNA

The fluorescence energy transfer (FET) between Acridine Orange and Safranine T, two intercalators of DNA, was studied in this paper. The FET efficiency between Acridine Orange and Safranine T is higher and the critical distance, R(0), is longer in the intercalated state than in the free one. A new method for the determination of calf thymus DNA (ctDNA) was presented. The linear range of the calibration curve is (0 approximately 1.1)x10(-5) mol l(-1) in bases for ctDNA, and the limit of detection is 2.6x10(-7) mol l(-1).     

双大环多胺Zn(Ⅱ)配合物及其与DNA作用的溴乙锭荧光探针

以1,4,7,10-四氮杂环十二烷(Cyclen)为原料合成的一种新型双大环多胺配体及其双核Zn2+配合物,其结构用1H NMR、质谱和元素分析等测试技术进行了表征。 以溴乙锭(EB)为探针,用荧光光谱法研究了双环多胺配体及其Zn(Ⅱ)配合物与小牛胸腺DNA的作用,当cComplex 6/cDNA=0.51时,DNA/EB体系的荧光强度降低至原来的47.3%,表明双大环配合物是以嵌入方式与小牛胸腺DNA结合。 化合物对DNA/EB体系的荧光猝灭顺序为：双大环多胺双核Zn(Ⅱ)配合物＞双大环多胺配体＞四氮杂环多胺Zn(Ⅱ)配合物＞四氮杂环多胺。     

4-Anilinopyrimido[4',5':4,5]selenolo(2,3-b)quinoline and 4-piperazino pyrimido[4',5':4,5]selenolo(2,3-b)quinoline: new DNA intercalating chromophores with antiproliferative activity

We have used circular dichroism, hydrodynamic methods, absorbance, and fluorescence titration to study the interaction of 4-anilinopyrimido[4',5':4,5] selenolo (2,3-b)quinoline (APSQ) and 4-piperazinopyrimido[4',5':4,5] selenolo(2,3-b)quinoline (PPSQ) with DNA. The association constants of APSQ and PPSQ were of the order of 10(4)M(-1). The fluorescence properties at ionic strength 0.01M are best fit by the neighbor exclusion model, with K=0.58-9.2 x 10(4)M(-1) and an exclusion parameter of 0.9-6.4 bp. Binding to the GC-rich DNA of Micrococcus lysodeikticus was stronger than the binding to calf thymus DNA, suggest that drug binds preferentially to G+C pairs at low r. CD spectra indicate that stacking of these compounds with DNA induces a strong helicity in the usually disordered structure of this double strand. Viscosity experiments show with sonicated calf thymus DNA with PPSQ an twice increase in slope (m) as that with APSQ. PPSQ increases the T(m) for calf thymus DNA melting by approximately 10 degrees C as binding approaches saturation, with biphasic melting. The cytotoxicities of these compounds on leukemia HL-60, K-562, B16F10 melanoma and Colo-205 are quite similar and inhibition (IC(50)) was in the range of 0.39-9.80 microM. The anticancer efficacy against B16F10 melanoma has provided evidence of major anticancer activity for PPSQ. Single or multiple intraperitonial (i.p.) doses of drug proved high level activity against the subcutaneous (s.c.) grafted B16 melanoma, significantly increase in life span (ILS 139% and 170%). The aim of this study was to analyze the physiochemical properties of these compounds in an attempt to understand its superior biological activity.     

BINDING, EXCITATION ENERGY TRANSFER AND PHOTOSENSITIZATION IN GRISEOFULVIN-DNA MIXTURES

Abstract— The weak and reversible binding of the antifungal drug, griseofulvin (GF), to calf thymus DNA has been demonstrated by difference spectroscopy and the quenching of the fluorescence of GF by DNA observed. The value of K _n was determined to be 800 M ^-1by fluorescence quenching titration. Adenosine and guanosine also exhibit difference spectra with GF and quench GF fluorescence indicating that they may be the site of both binding and energy transfer. The in vitro photosensitization of DNA by griseofulvin is shown to occur. It is proposed that the clinically observed in vivo photosensitizing action of griseofulvin may result from binding followed by excitation energy transfer and that this may also be important in the antifungal activity of the drug.     

DNA structure, binding mechanism and biology functions of polypyridyl complexes in biomedicine

There is considerable research interest and vigorous debate about the DNA binding of polypyridyl complexes including the electron transfer involving DNA. In this review, based on the fluorescence quenching experiments, it was proposed that DNA might serve as a conductor. From the time-interval CD spectra, the different binding rates of A- and A-enantiomer to calf thymus DNA were observed. The factors influencing the DNA-binding of polypyridyl complexes, and the potential bio-functions of the complexes are also discussed.     

三聚氰胺对DNA潜在损伤作用的研究

在生理酸度条件下(pH 7.4),采用溴化乙锭(EB)为荧光探针的荧光光谱法、I-离子荧光猝灭效应、DNA熔点和粘度效应等手段,研究了三聚氰胺与DNA的相互作用。随着DNA的加入,三聚氰胺的荧光强度明显减小而且三聚氰胺能够猝灭DNA-EB复合物的荧光,说明三聚氰胺能够竞争置换EB而与DNA作用;三聚氰胺的加入使得DNA的粘度增大,DNA-EB的熔点降低;DNA的加入减小了I-对三聚氰胺荧光的猝灭程度。三聚氰胺以嵌插方式作用于DNA的亲核位点,意味着三聚氰胺进入生物体后有可能通过形成DNA加合物的形式造成DNA损伤,从而最终导致基因突变。     

Antitumor activity of 4-amino and 8-methyl-4-(3diethylamino propylamino)pyrimido[4',5':4,5]thieno (2,3-b) quinolines

The interaction of 4-aminopyrimido [4',5':4,5] thieno (2,3-b) quinoline and 8-methyl-4-(3-diethylaminopropylamino) pyrimido [4',5':4,5] thieno (2,3-b) quinoline with DNA was studied by UV-Vis and fluorescence spectrophotometry as well as by hydrodynamic methods. On binding to DNA, the absorption spectra underwent bathochromic and hypochromic shifts and the fluorescence was quenched. These compounds are able to bind to DNA with an affinity of about 10(6) M(-1) for calf thymus DNA at ionic strength 0.01 M and their intercalating characteristic (lengthening of the DNA) depends upon the length of the chain. Binding to the GC-rich DNA of Micrococcus lysodeikticus was stronger than the binding to calf thymus DNA at ionic strength 0.01 M. The cytotoxicities of these compounds on leukemia HL-60, melanoma B16F10 and neuro 2a cells are quite similar and inhibition (IC50) is in the range of 0.992-3.968 microM. The anticancer efficacy against B16 melanoma, has provided evidence of major antitumor activity for 8-methyl-4-(3diethylaminopropylamino) pyrimido [4',5':4,5] thieno(2,3-b)quinoline. Single or multiple intraperitonial (i.p) doses of drug proved high level activity against the subcutaneous (s.c) grafted B16 melanoma, significantly increasing survival (p<0.001) and inhibiting tumor growth (T/C of 4%). This study offers a new intercalation functional group to DNA-targeted drug design.