Humic-like compounds formed from -tryptophan and -glucose in the presence of CU (II)

This study concerns the humic-like polymeric compounds formed by D-glucose plus L-tryptophan and by L-tryptophan alone, both on Cu-saturated nontronite, montmorillonite and kaolinite and on quartz in the presence of Cu(II) ions. These mineral-organic systems were kept in thermostat at 70°C for 30 days and submitted to alternate wetting-drying cycles. Higher amounts of humic-like compounds were extracted from quartz-organic than from clay-organic systems, showing the remarkable action of Cu(II), which even overcame the high catalytic power of clays.