Mitra A, Nath R K, Chakraborty A K
Department of Chemistry, Tripura University, Agartala, India.
Indian J Biochem Biophys. 1992 Oct;29(5):411-4.
The acidic capsular polysaccharide isolated from Klebsiella K7 induced metachromasy in the cationic dye pinacyanol chloride indicating its chromotropic character. Interaction of the biopolymer with the cationic dye was studied by visible absorption spectrophotometry, and thermodynamic parameters of the interaction evaluated. The polymer induced a metachromatic blue shift in the spectrum from 600 nm to 495 nm. The spectral changes were studied during interaction of the dye with the polymer at different polymer/dye molar ratios (P/D = 0 approximately 50). Effects of co-solvents on the stability of the dye-polymer compound were studied. A complete reversal of metachromasy was observed upon addition of different alcohols and urea solution. Thermodynamic parameters obtained from the spectral data indicated chromotropic character of the polymer in interacting with the cationic dye molecules in solution.
从肺炎克雷伯菌K7分离出的酸性荚膜多糖可使阳离子染料哌花青氯发生异染现象，表明其具有变色特性。通过可见吸收分光光度法研究了该生物聚合物与阳离子染料的相互作用，并评估了相互作用的热力学参数。该聚合物在光谱中引起了从600nm到495nm的异染蓝移。研究了在不同聚合物/染料摩尔比（P/D = 0至50）下染料与聚合物相互作用期间的光谱变化。研究了共溶剂对染料-聚合物化合物稳定性的影响。加入不同的醇类和尿素溶液后，观察到异染现象完全逆转。从光谱数据获得的热力学参数表明该聚合物在溶液中与阳离子染料分子相互作用时具有变色特性。
