Effect of hydrogen peroxide on the binding of Merocyanine 540 to human erythrocytes

The fluorescent dye Merocyanine 540 (MC540) is often used as a probe to monitor the molecular packing of phospholipids in the outer leaflet of biomembranes. In a previous study we showed that the increased staining of erythrocytes with a perturbed membrane structure was mainly due to an increase in the fluorescence yield of cell-bound MC540, rather than to an increase of the number of bound molecules. Erythrocytes and ghosts exposed to continuous fluxes of H₂O₂ exhibited pronounced lipid peroxidation. Further, red blood cells subjected to this form of oxidative stress also showed increased staining with MC540. It appeared that this was caused by a strong increase in binding of MC540, together with a slight red shift of the fluorescence emission maximum and a small increase in the fluorescence yield of bound MC540. The changed MC540 binding characteristics were not observed when lipid peroxidation was suppressed by the presence of the antioxidant BHT in the incubation medium. However, open ghosts exposed to H₂O₂ showed no increase of MC540 binding, excluding a direct involvement of lipid peroxidation. Measurement of fluorescence emission spectra and gel filtration studies showed that MC540 can bind to H₂O₂-exposed hemoglobin. Experiments with erythrocytes lysed in hypotonic medium after exposure to H₂O₂ revealed that peroxidation of lipids with H₂O₂ induced a non-specific permeabilization of the plasma membrane to MC540, thereby allowing MC540 to bind to the oxidatively denatured, more hydrophobic hemoglobin. These results indicate that conclusions about packing of phospholipids in the outer leaflet of the membrane based on increased MC540-staining should be drawn with care. Received 27 September 1996; received after revision 5 November 1996; accepted 27 November 1996     

含咔唑偶合组分单偶氮分散染料应用性能研究

咔唑杂环化合物为偶合组分的新型单偶氮分散染料曾被国内某企业替代分散黄RGFL作过批量拚色；其耐碱、耐还原性较强、色光稳定。本文对2-氯-4-硝基和2，5-二氯苯胺重氮盐与咔唑N-乙基咔唑偶合成的4只染料的常规高温高压和热熔法染色性能、牢度作了研究：它们的吸附等温线类似朗格缪尔型；高温高压法的提升力为20～40g／L；190℃升华牢度为3～4级；3％染色深度棉沾色3～5级、2％时皂洗原样变化3～4级、白布沾色3～5级，干、湿摩擦牢度4～5级；极限温升131～148℃；热熔法染色最佳温度为200～210℃；固色率74～94％，提升力为20～40g／L；3％染色深度棉沾色2～3级；干、湿摩牢度为4～5级。高温高压法染色吸尽率、存在的两法差异及部分牢度尚待改进。     

循环伏安法测定光敏染料的半波电位

用循环伏安法测定了几种若丹菁和份菁的半波电位．计算了染料的最低空位能级和最高占有能级．结果表明该法灵敏度高，重现性好，速度快．     

钼的几种有机染料显色比较研究

本工作系统地研究以以Mo-SCN_二元体系为基础，分别与己基紫、结晶紫、孔雀绿．罗丹明B、罗丹明6G．甲基紫及次甲基蓝7种不同类型的碱性染料和表面活性剂组成的显色体系的光度法分析性能，提出了2种新的体系，并将一种用于某些样品中钼的测定。     

红外激光调Q,锁模染料的研究

合成了６个结构为（ＲＣＳＣＳＲ’）２Ｎｉ的镍铬硫代双烯型红外激光调Ｑ、滑模染料。它们的最大吸收长在９３０￣１４５５ｎｍ。对１０６４ｎｍ激光获得满意调Ｑ。脉宽３￣６ｎｓ；对１０７９ｎｍ及１３４０ｎｍ激光进行锁模，脉宽４０ｐｓ及９０￣１００ｐｓ。     

闪光灯泵浦多重染料激光器

研究了染料体系的光谱转换率、热效应和多重染料对灯泵染料激光器输出的影响；通过计算施主和受主的光谱转换率，得出系统中施主和受主浓度都低的结论；提出了分离施主和受主是使用多重染料的最佳方案．实验表明，分离Ｃ６－Ｒ６Ｇ体系比单独Ｒ６Ｇ体系激光输出高２．６倍，而分离三重染料体系又比分离Ｃ６－Ｒ６Ｇ体系使激光输出提高１．８倍，理论计算与实验结果相符．     

等色染料离子对──溴酚蓝·亚甲蓝体系在测定某些二价金属方面的应用

研究了溴酚蓝（ＢＰＢ）·亚甲蓝（ＭＢ）等色染料离子对在萃取光度法中测定Ｆｅ、Ｃｏ、Ｎｉ、Ｚｎ、Ｃｄ、Ｃｕ及Ｈｇ的应用。将二价金属离子和邻二氮菲及溴酚蓝形成三元络合物Ｍｅ（ｐｈｅｎ）３·ＢＰＢ〔１〕，并用二氯乙烷萃取分离，把有机相中的三元络合物用酸解析并反萃入水相，加入与溴酚蓝等色的亚甲蓝溶液继续萃取，萃入有机相的等色染料离子对因双显色协同作用和增敏效应而提高了测定方法的灵敏度，所测Ｆｅ、Ｃｏ、Ｎｉ、Ｚｎ、Ｃｄ、Ｈｇ的摩尔吸光系数均在１０５Ｌ／ｍｏｌ·ｃｍ以上。     

稀土与酸性染料的相互作用研究

通过在不同酸度下，不同类型的稀土与染料相互作用，结果表明稀土与酸性染之间没有发生络合作用。