J-BAND INDUCED IN PSEUDOISOCYANINE BY POLYANION OF HIGH CHARGE-DENSITY

Induction of J-band in N,N''-diethylpseudoisocyanine chloride (PIC) depended primarily on the suitable conformation of the polyanion in addition to its charge density. PIC failed to exhibit J-band with Bael (Aegle marmelos) exudate gum polysaccharide, BP (charge density 0.19 per monosaccharide unit) and Bael fruit gum polysaccharide, AMA (charge density 0.074). Unlike the failure of chondroitin 4-sulphate (CS-4, charge density 1.0) to exhibit J-band chondroitin 6-sulphate (CS-6, charge density 1.0), Heparin (Hep, charge density 1.5) and dextran sulphate (DS, charge density 2.0) exhibited sharp red shifted J-band in PIC (1.0 x 10(-5) M). The stoichiometry of polyanion-dye compounds was found to be approximately 2 : 1 for the systems exhibiting J-band. Ethanol concentrations needed to reverse the exhibition of J-band were 40, 30 and 20% for PIC-DS (P/D = 3.0), PIC-Hep (P/D = 10.0) and PIC-CS-6 (P/D = 42.0) systems respectively.