Bhattacharjee and colleagues [28] presented pyrazolone compounds 32, 33, 34 and 35 (Fig. 3 ) which exhibited favorable inhibitory effect against Bacillus cereus with the MIC values of 0.78, 0.78, 0.78 and 0.39 mg/mL, respectively, and suppressed the growth of Klebsiella pneumoniae with the MIC values of 0.78, 0.39, 0.39 and 0.78 mg/mL, respectively.