The Effect of 3-Chloro-Substitution on the Antimicrobial Activities of Some Cobalt (II) *-Ketoamines and Their Adducts

Abstract

Four cobalt (II) 3-chloro-ß-ketoamines, seven cobalt (II) ß-ketoamines and fifteen 2,2'-bipyridine and 1,10-Phenanthrdine adducts were screened against thirteen organisms namely Bacillus subtilis  Bacillus cereus, Staphylococcus aureus, Pseudomonas flourescens, Pseudomonas auriginosa, Escherichia coli, Aeromonas spp, Flavobacterium spp, Salmonella spp and Streptococcus pyogens. The cobalt (II) ß-ketoamines were more effective than their cobalt (II) 3-chloro-ß-ketoamines analogs. The adducts all showed less antimicrobial activities than the parent, cobalt(II) ß-ketoamines and cobalt (II) 3-chloro ß-ketoamines, even though the cobalt (II) ß-ketoamines adducts, were more effective than their corresponding cobalt (II) 3-chloro-ß-ketoamine adducts. Antimicrobial activities in all cases, were related to the electron density on the coordinated cobalt atom. Thus, the lower the electron density on the coordinated cobalt atom in these ß-ketoamines, 3-chloro-ß-ketoamines and adducts the lower the antimicrobial activity.

     The minimum inhibitory concentrations for cobalt (II) ß-ketoamines and adducts were between 1.25-3.95 mg/ml while that of cobalt(II) 3-chloro-ß-ketoamines and adducts were between 1.29-5.20mg/ml.