Comprehensive Physicochemical Investigation of a Water-Soluble Adduct of C70 with l-Methionine and l-Cysteine

We study the physicochemical and biological properties of water-soluble adducts of fullerene C70 with l-methionine (C70-Met, C70(C5H11NO2S)3) and l-cysteine (C70-Cys, C70(C3H7NO2S)3). The adducts were characterized using 13C NMR, IR, and UV spectroscopy, elemental analysis, and HPLC. The measured physicochemical properties included temperature and concentration dependence of density, viscosity, refraction, electrical conductivity, surface tension of aqueous solutions, solubility in binary systems (C70-Met–H2O and C70-Cys–H2O) and ternary systems (C70-Met–NaCl–H2O and C70-Cys–NaCl–H2O), as well as determination of the partition coefficient in an n-octan-1-ol–water system. In addition, investigation of binding to human serum albumin and DNA was conducted as well as antiradical activity in the model reaction with a stable 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) was studied.