Cytostatics. VIII. Relations between chemical constitution and antimicrobial activity in beta -aminoketones

Six aliphatic beta -amino ketones, 5 alpha -phenyl-beta -amino ketones, 7 beta - aminopropiophenones, and 9 alpha -phenyl-beta -aminopropiophenones were tested for in vitro fungistatic and bacteriostatic activity and were compared with dimethylaminoacetophenone, 1-dimethylamino-4-phenyl-4-butanone, 1- dimethylamino-3-phenylpropane, 1-dimethylamino-3-phenyl-3-propanol, and 1-dimethylamino-2,3-diphenyl-3-propanol. Aliphatic beta -amino ketones had no significant antimicrobial activity. With phenyl-substituted beta -amino ketones, antimicrobial activity depended on the no. and position of the aromatic residues, and substitution on the carbonyl C atom or the alpha -C atom by a phenyl residue or the presence of such residues at both C atoms were prerequisites for good antimicrobial activity. Replacement of the dimethylamino group with diethylamine, pyrrolidine, piperidine, or morpholine groups reduced activity, as did incorporation of methoxy and chloro groups into the benzene ring of the beta - aminopropiophenones and alpha -phenyl-beta -aminopropiophenones