Induced optical activity in poly-L-lysine-methyl orange system

The absorption and cicular dichroism spectra of the complex of poly-L -lysine (PLL) in the random coil form with methyl orange (MO) have been measured in aqueous solution. A new absorption band is observed at the shorter wavelength compared with that of the free dye. Although MO does not show a formation of dimer or aggregation with an increase in concentration, circular dichroism bands are observed at the wavelength corresponding to the wavelength of the new absorption band. These induced circular dichroism bands may arise from the dimeric MO molecules bound to PLL in the random coil form. The main contribution to the interaction between MO molecules is shown to be the electro static interaction. The observed circular dichroism spectra and the configuration of dimeric MO molecules bound to PLL can be explained by the dipole couping mechanism.     

Enzymatic Maceration of Plant Tissue

Tissue cells of Vicia faba were separated from the leaf pieces by the pectinase treatment after which the chlorophyll determination method was employed. The separation proceeded at a constant rate for 3 hours', the maximum rate of separation was at pH 5.3. The optimal pH shifted to 5.5 in the presence of 0.001 M 2Na-ethylenediaminetetraacetic acid (EDTA), which accelerated the separation at pH levels higher than 5.5. The separation was enhanced by NaCl and MgCL₂ and delayed by CaCl₂ and hypertonicity produced by sugars. Indoleacetic acid (IAA) and naphthaleneacetic acid (NAA) accelerated the separation at physiological concentrations. The rate of separation differed markedly by the age of the leaf and the species which offered the substrate material.