Synthesis, in vitro antitubercular activity and 3D-QSAR of novel quinoxaline derivatives.

Twenty new quinoxalines bearing azetidinone and thiazolidinone groups were synthesized by cyclocondensation of Schiff bases of quinoxaline-2, 3-dione and were characterized with several analytical tools. They were tested against Mycobacterium tuberculosis H37Rv at a concentration of 10 μg/mL by Microplate Alamar Blue Assay method. Quinoxaline derivatives with 2-chloro, dimethylamino and nitro substitutions exhibited in vitro activity, comparable to that of the drug, isoniazid. Three-dimensional quantitative structure-activity relationship studies indicated that electrostatic and steric field descriptors could explain the observed activity. The developed model fits the data well and has good predictive capability (r² = 0.81, q² = 0.71, F = 27.06, r² _pred = 0.84, r²(m) = 0.84, r² BS = 0.80). Electronegative groups play an important role in the antitubercular activity.