INVESTIGATION OF THE ANTIVIRAL ACTION OF THE PHOTOACTIVE COMPOUND PHENYLHEPTATRIYNE

Abstract— Murine cytomegalovirus, a herpes virus, was used as a model virus to investigate the mechanism of the anti-viral action of phenylheptatriyne in long wave ultraviolet light. The genome and proteins of the inactivated virus penetrated the nuclei of susceptible cells normally. Furthermore, the viral genome did not contain extra single strand breaks or cross-links. However, cells infected with the treated virus did not synthesize late viral proteins, as determined by polyacrylamide gel electrophoresis. nor did they synthesize late viral RNA and viral DNA according to nucleic acid hybridization tests. Thus the compound may interfere with an early viral function so that the replication cycle cannot proceed.     

菁染料与溴化银相互作用性质的研究

本文用计时电位法及电位滴定研究了十六种不同染料与溴化银之间的相互作用,进一步证明了具有离域π-电子的菁染料才能与卤化银形成络合物的论点。从得到的平衡常数K表明,固体表面上的卤化银-染料与溶液中银离子-染料具有相同键性质,都是银离子与染料离域π-电子作用的结果。     

ON THE NATURE OF INTERACTION BETWEEN PROFLAVINE and DNA

Abstract— The fluorescence decay of the mutagenic drug proflavine (PF) bound to DNA at a phosphate-to-drug ratio of 420 is found to be a non-exponential function of time. The deviation from exponentiality is shown to increase with increasing GC content of DNA. Thus, heterogeneity in the high affinity binding sites is clearly demonstrated. The nucleotides guanosine-5'-monophosphate (GMP) and cyti-dine-5'-monophosphate (CMP) are shown to form complexes with PF in 10^-3M sodium cacodylate buffer at pH 6.6. In addition, GMP quenches substantially the fluorescence of PF while CMP enhances it slightly. The fluorescence decay curves for 5 × I0^-6 M PF in the presence of GMP concentrations greater than 10^-2 M exhibit a deviation from exponentiality which parallels that exhibited by the fluorescence decay curves for PF bound to DNA of increasing GC content. It is inferred that (a) guanine is responsible for the quenching of the fluorescence of PF on binding to DNA; and (b) the forces involved in the interaction between PF and DNA are specific in nature. The implications of these findings concerning the mutagenic properties of acridine derivatives are discussed. Nanosecond depolarization studies reveal a quite fast depolarization of the fluorescence of bound PF; for the PF- Cl. perfringens DNA complex the rotational correlation time is about 26 ns. Time-resolved emission spectroscopy in the nanosecond scale demonstrates that, despite the change in the orientation of the drug, the electronic structure of the PF-DNA complex is not substantially altered during the lifetime of the excited singlet electronic state of the drug.     

四氮大环铜配合物和DNA的相互作用

本文合成了四氮大环铜配合 物，以紫外和溴化乙锭荧光法研究了它和DNA的相互作用，以琼脂糖凝胶电泳就它作为化学核酸酶的可能性进行了初步研究。     

INTERACTION BETWEEN UPOSOMES AND MONOLAYERS IN THE PRESENCE OF CALCIUM

Abstract

The interaction between phospholipid vesicles (phosphatidylcholine : phosphatide acid, 90:10 w/w) and phosphatidylcholine : cholesterol (70:30, molar ratio) monolayers at air/water interfscks has been studied at. several concentrations of calcium cation ( Ca²⁺). The liposome vesicles were SUVs and MLVS.

The vesicles interact with the monolayers, rapidly causing a large increase in surface pressure. Limiting values of surface pressure, 2.07-6.99 mN.m-1 for SUVs, and 7.01-11.11 mN.m^?1 for MLVs, were reached in less than 40?min.

Calcium ion concentration affects the liposome size in MLVs, producing an increase of gyration radius. The SUVs are little influenced. The change in size can be due to a variation of liposome composition induced by calcium: cholesterol molecules can migrate from monolayer to liposomes and the redistribution of exchanged lipids in the outer bilayer can also explain the size variation.     

壳聚糖与尿素的相互作用及其应用研究进展

尿素能够显著破坏甲壳素/壳聚糖分子氢键结构和疏水相互作用,增加其临界胶束浓度,促进多糖大分子的溶解,并能减少其在溶液中的自聚集现象.碱-尿素水溶液可以作为一种新型的甲壳素/壳聚糖绿色溶剂,有望用于对刺激性要求较为苛刻的食品、生物医学等领域.壳聚糖衍生物特别是其与过渡金属离子的配合物具有良好的尿素吸附功能,可用于尿毒症患者血液中小分子毒物的吸附,对机体刺激性小且不吸附血清蛋白等生物大分子.有望成为血液灌流治疗法中清除尿素等小分子毒性物质的良好吸附剂.壳聚糖还可以作为包膜材料,制备壳聚糖包膜尿素,与普通的包膜尿素相比性能更为优越.     

磺化锌酞菁与胶束间的相互作用

用吸收光谱和荧光光谱研究了不同磺化程度酞菁与不同胶束间的相互作用并计算了结合常数。低磺化程度酞菁与三类胶束间均可发生相互作用,其标志是胶束的解聚作用;而高磺化程度酞菁与此显著不同,可结合在阳离子胶束表面,与非离子胶束无明显作用,而阴离子胶束对磺化酞菁只起促聚作用。用磺化程度变化导致酞菁分子体积、电荷及疏水性变化解释了实验结果。     

竹红菌甲素和吲哚类化合物的相互作用

本文利用吸收光谱,荧光光谱研究了竹红菌甲素(以下简称HA)和吲哚类化合物的相互作用。发现HA和吲哚类化合物在一定条件下可形成复合物。这种复合物带有电荷转移性质。吲哚环上带有给电子取代基,位阻小,溶剂的极性大和溶液呈中性有利于该复合物的形成。     

稀土与染料的相互作用

本文用可见吸收光谱、核磁共振谱、红外光谱等分析方法,研究了Nd、Eu与阳离子染料、酸性染料、活性染料及直接染料之间的相互作用。结果表明稀土与大多数染料之间没有形成稳定的配合物,在中性或酸性条件下与含磺酸基的染料之间只形成磺酸盐,与含羧酸基的染料之间形成羧酸盐。只有与酸性媒介染料之间形成稳定的配合物,其结构与铬及其配合物相似。     

阴离子型聚氨酯水分散液与明胶相互作用的研究

将明胶作为皮蛋白的模型化合物与阴离子型聚氨酯水分散液（ＡＰＵ）反应，来探讨聚合物型助剂与皮革在分子水平上的相互作用机理．该文采用紫外 可见光谱、红外光谱研究了混合体系对ｐＨ值的依赖性，明胶／ＡＰＵ配比、极性化合物对体系相互作用的影响．     

曙红Y与CTMAB非共价作用机理的研究及应用

用微相吸附-光谱修正(MPASC)技术研究了曙红Y与阳离子表面活性剂CTMAB相互作用的机理。在pH 6.8的缓冲溶液中进行试验,结果表明,上述反应属Langmuir单分子层吸附。按曲线的截距计算反应产物中曙红Y与CTMAB的结合比为1∶2(分别在20,40及60℃试验)。按曲线的斜率计算结合反应的常数,在不同温度条件下测得的常数值不同:2.56×105(20℃),1.11×105(40℃)及3.86×104(60℃)。在曙红Y与CTMAB的反应体系中加入定量的阴离子表面活性剂(如十二烷基磺酸钠,SLS),则一定量的曙红Y将从CTMAB吸附聚合体中释出。根据这一灵敏的置换反应,建立了污水中阴离子洗涤剂的测定方法。此法用于污水样品分析,得到的RSD(n=6)值小于5%。用标准加入法检测方法的回收率在99.8%~108.9%之间。     

INFLUENCE OF SURFACE-MODIFICATION FOR CALCIUM CARBONATE ON THE INTERACTION BETWEEN THE FILLERS AND POLYDIMETHYLSILOXANE

The surface of calcium carbonate(CaCO_3)particles was modified with stearic acid(SA)and the chemical structures of the product were characterized by FT-IR analysis.The interaction between polydimethylsiloxane(PDMS)and CaCO_3 fillers with different surface character was investigated by means of dynamic rheological and bound rubber tests for uncured compounds and mechanical properties measurements for the corresponding vulcanites.The results of dynamic tests indicate that with the increase of SA mass fract...     

钨基加氢脱氮催化剂载体与活性前身物的作用

为研究载体表面化学性质和钨前物结构对钨基加氢脱氮催化剂活性的影响，以ＩＲ，ＸＲＤ，程序升温硫化方法，研究了十二磷钨酸和偏钨酸铵两种不同结构的前身物在Ａｌ２Ｏ３的活性表面的分散状态。     

THE ANTI-HIV ACTIVITIES OF PHOTOACTIVE TERTHIOPHENES

Abstract— Various synthetic analogues of the naturally occurring terthiophene, α-terthienyl (αT), were evaluated for anti-human immunodeficiency virus (HIV) activity. The compounds were incubated individually with a known amount of the virus, with or without UVA radiation (long-wavelength ultraviolet) and residual virus was monitored for its ability to produce cytopathic effects in cell culture and the production of virus-specific protein (p24). The basic terthiophene structure was essential for good anti-HIV activity, although various side chains, such as alcohols, bromo, methyl, thiomethyl and trimethylsilyl groups, permitted retention of maximum activity. Under optimum conditions, as little as 12 ng/mL of these compounds ( i.e approximately 3 × 10⁻⁸ M ) could inactivate 10³ infectious virions. None of the compounds however were more active than αT itself. In all cases, UVA radiation was essential. Several side chains decreased the antiviral efficacy, and some side chains abrogated the activity.     

INTERACTION BETWEEN THE SURFACE GLYCOSYLATED POLYPROPYLENE MEMBRANE AND LECTIN

A glycopolymer bearing glucose residues was tethered onto the surface of polypropylene microporous membrane by UV-induced graft polymerization ofα-allyl glucoside.Concanavalin A (Con A),a glucose recognizing lectin,could be specifically adsorbed to the membrane surface.On the other hand,the membrane surface showed no recognition ability to another lectin peanut agglutinin.Moreover,the recognition complex between the glycosylated membrane surface and Con A could be inhibited by glucose and mannose solutio...     

染料和聚电解质间的相互作用——在染料-磺化聚苯乙烯络合物中的能量转移和染料荧光强度的增强

本工作对磺化聚苯乙烯-吖啶橙体系的光物理行为进行了研究。发现吖啶橙的荧光强度强烈地依赖于所用染料和聚电解质的当量比(P/D)。在P/D=100时观察到有最大的荧光强度。经过校正,此值和Fox等研究苯乙烯和乙烯基共聚物的能量转移中所得结果基本一致。这表明在高分子电解质-染料络合物中能发生有效的能量转移。 本工作还研究了亚甲蓝对吖啶橙荧光的猝灭效应。观察到当体系中加入聚电解质时猝灭效应得以增强。     

粘度法研究PAM与R12SO3Na之间的相互作用

采用粘度法研究了纯水及含有NaCl和R_4OH(正丁醇)时, PAM(聚丙烯酰胺)与R_(12)SO_3Na(十二烷基磺酸钠)之间的相互作用。结果表明, 在所研究的范围内, PAM与R_(12)SO_3Na胶束之间能形成PAM-R_(12)SO_3Na胶束聚集体。但在纯水和NaCl溶液中, 两者之间的作用较弱。若体系中同时存在R_4OH时, 作用较强。可能是PAM分子中的—C=O —C—NH_2与混合胶束中的醇羟基以氢键相结合, 形成PAM-胶束聚集体, 所以体系的比浓粘度(ηsp/cp)随PAM浓度(cp)的降低而急剧增大, 表现出典型的聚电解质性质。     

THE PHOTOTOXICITY OF PHENYLHEPTATRIYNE: OXYGEN-DEPENDENT HEMOLYSIS OF HUMAN ERYTHROCYTES AND INACTIVATION OF Escherichia coli

Abstract— Phenylheptatriyne (PHT) plus near-ultraviolet light(320–400 nm; NUV) hemolyzed human erythrocytes in an oxygen dependent manner. When the phototoxicity of PHT plus NUV was tested with a series of Escherichia coli strains carrying all four possible combinations of genes controlling excision proficiency ( uvrA6 vs uvrA ⁺) and catalase activity (HPII, katF vs katF *), the membrane was found to be an important lethal target. Consistent with this observation. PHT plus NUV did not induce histidine independent ( his-4 ⁺) mutations in the four tester strains (RT7h-RT10h). Using tester strain RT10h, it was shown that there was no inactivation by PHT plus NUV in nitrogen. Results of experiments with an E. coli fatty acid auxotroph (K1060) treated with PHT plus NUV are also consistent with membrane proteins being the chief targets for attack. Radicals were formed during the photolysis of PHT plus NUV in aqueous solutions, both in the presence of air and under nitrogen. Since PHT plus NUV did not hemolyze erythrocytes or inactivate E. coli cells under nitrogen, these radicals are not cytotoxic.     

INTERACTION BETWEEN TYROSINE AND DIVALENT SULFUR IN FLUORESCENCE QUENCHING AND IN THE PHOTOCHEMISTRY OF RIBONUCLEASE

Abstract— –Ribonuclease is inactivated in aqueous solution by u.v. light through different mechanisms according to whether divalent sulfur or aromatic amino acids are the primary light absorbers. At 284 nm, absorbed mainly by tyrosine, the presence of O₂ inhibits photoinactivation and H₂S formation, but does less so at 254 or 313 nm. Based on data with model substances containing disulfide groups a mechanism is indicated in which excited tyrosine is quenched through electron transfer to adjacent divalent sulfur within the protein. Disulfide compounds are shown to be very efficient quenchers of tyrosine fluorescence.     

PHOTOCHEMISTRY OF THE PHOTOTOXIC POLYACETYLENE PHENYLHEPTATRIYNE*

Abstract— Investigation of the photochemistry of the phototoxic polyacetylene phenylheptatriyne, PHT, was undertaken to obtain further information on competing photo-oxidative type II and non-oxidative processes observed in vivo. Laser excitation (308 or 337 nm) led to the formation of a strong triplet signal with a lifetime of 28 μs in MeOH. The triplet was efficiently quenched by the triplet quencher 1,3-octadiene (k_q - 1.6 × 10⁹M^-1s^-1). Quenching by O₂ occurred with a rate constant (1.7 × 10⁹M^-1s^-1) comparable to the rate of electron transfer to methylviologen (1.4 × 10⁹M^-1 s^-1). The formation of singlet oxygen established earlier (type II reaction) in the former case and the semioxidized PHT radical in the latter case are consistent with the competing phototoxic processes observed in vivo.