The Schiff base 2-[(E)-(quinolin-3-ylimino)methyl]phenol (H-QMP) was crystallized in Pc space group and complexed with Ni(II) and Co(II) in [M(QMP)(2)] and Cu(II) and Zn(II) in [M(QMP)(CH3COO)]H2O compositions. Elemental analyses, mass spectrometry, IR, UV-vis spectroscopy, conductance study and magnetic susceptibilities were used to characterize the complexes. The thermograms obtained in the range of 30-1000 degrees C were used for kinetic and thermodynamic calculations. The activation energies and order of pyrolysis were calculated using Horowitz-Metzger method. The calculated activation energies were subsequently used for the calculations of thermodynamic parameters including Delta S*, Delta H* and Delta G*. It was found that the thermal stability and activation energy follow the order Cu(II)>Ni(II)>Co(II)>Zn(II) and E-Ni* > E-Cu* > E-Co* > E-Zn*, respectively. All the compounds were also studied for their urease and alpha-chymotrypsin inhibition, showing medium to moderate activities for both the enzymes except nickel complex. Nickel complex shows IC50 = 9.9 +/- 0.124 mu M +/- SEM, and the activity was rationalized by carrying out molecular modeling studies. (C) 2013 Elsevier B.V. All rights reserved.